Which head element is more effective for cement augmentation of TFNA? Helical blade versus lag screw.

BACKGROUND: Early fixation and rehabilitation is the gold standard treatment for intertrochanteric femur fractures. Cement augmentation through perforated head elements has been developed to avoid postoperative complications such as cut-out or cut-through. The purpose of this study was to compare two head elements in terms of cement distribution using computed tomography (CT) and to examine their initial fixation and clinical outcomes. METHODS: Elderly patients who had intertrochanteric fractures were treated with a trochanteric fixation nail advanced (TFNA) helical blade (Blade group) or a TFNA lag screw (Screw group). In both groups, 4.2 mL of cement was injected under an image intensifier (1.8 mL of cement was directed cranially and 0.8 mL each caudally, anteriorly, and posteriorly). Patient demographics and clinical outcome were investigated post-operatively. Cement distribution from the center of the head element was evaluated with CT. Maximum penetration depth (MPD) were measured in the coronal and sagittal planes. On each axial plane, the cross-sectional areas in the cranial, caudal, anterior and posterior directions were calculated. The sum of cross-sectional areas (successive 36 slices) was defined as the volume of the head element. RESULTS: The Blade group included 14 patients, and the Screw group included 15 patients. In the Blade group, MPD in the anterior and caudal direction was significantly greater than that in the posterior direction (p < 0.01). In the Screw group, volume in the cranial and posterior direction was significantly greater than that in the Blade group (p = 0.03). Subsequently, the total volume in the Screw group was significantly larger than that in the Blade group (p < 0.01). No significant correlation was detected between bone mineral density, T score, young adult mean, and total cement volume. Change in radiographic parameters and clinical outcome such as Parker score and visual analog scale were similar in both groups. No patients suffered from cut-out / cut through or non-union. CONCLUSIONS: The position of cement distribution through the lag screw is different from that through the helical blade, and the total volume of the head element is significantly larger in the lag screw. Both groups had similarly effective results in terms of mechanical stability after surgery, postoperative pain and early phase of rehabilitation. TRIAL REGISTRATION: Current Controlled Trials ISRCTN45341843, 24/12/2022, Retrospectively registered.

Biomechanical analysis of recently released cephalomedullary nails for trochanteric femoral fracture fixation in a human cadaveric model.

BACKGROUND: Recently, two novel concepts for intramedullary nailing of trochanteric fractures using a helical blade or interlocking dual screws have demonstrated advantages as compared to standard single-screw systems. However, these two concepts have not been subjected to a direct biomechanical comparison so far. The aims of this study were to investigate in a human cadaveric model with low bone quality (1) the biomechanical competence of nailing with the use of a helical blade versus interlocking screws, and (2) the effect of cement augmentation on the fixation strength of the helical blade. METHODS: Twelve osteoporotic and osteopenic human cadaveric femoral pairs were assigned for pairwise implantation using either a short TFN-ADVANCED Proximal Femoral Nailing System (TFNA) with a helical blade head element or a short TRIGEN INTERTAN Intertrochanteric Antegrade Nail (InterTAN) with interlocking screws. Six osteoporotic femora, implanted with TFNA, were augmented with bone cement. Four groups were created: group 1 (TFNA) paired with group 2 (InterTAN), both consisting of osteopenic specimens, and group 3 (TFNA augmented) paired with group 4 (InterTAN), both consisting of osteoporotic specimens. An unstable trochanteric AO/OTA 31-A2.2 fracture was simulated and all specimens were tested until failure under progressively increasing cyclic loading. RESULTS: Stiffness in group 3 was significantly higher versus group 4, p = 0.03. Varus (°) and femoral head rotation around the femoral neck axis (°) after 10,000 cycles were 1.9 ± 1.0/0.3 ± 0.2 in group 1, 2.2 ± 0.7/0.7 ± 0.4 in group 2, 1.5 ± 1.3/0.3 ± 0.2 in group 3 and 3.5 ± 2.8/0.9 ± 0.6 in group 4, being significantly different between groups 3 and 4, p = 0.04. Cycles to failure and failure load (N) at 5° varus or 10° femoral head rotation around the neck axis in groups 1-4 were 21,428 ± 6020/1571.4 ± 301.0, 20,611 ± 7453/1530.6 ± 372.7, 21,739 ± 4248/1587.0 ± 212.4 and 18,622 ± 6733/1431.1 ± 336.7, being significantly different between groups 3 and 4, p = 0.04. CONCLUSIONS: Nailing of trochanteric femoral fractures with use of helical blades is comparable to interlocking dual screws fixation in femoral head fragments with low bone quality. Bone cement augmentation of helical blades provides significantly greater fixation strength compared to interlocking screws constructs.

Impact of Anterior Malposition and Bone Cement Augmentation on the Fixation Strength of Cephalic Intramedullary Nail Head Elements.

Background and Objectives: Intramedullary nailing of trochanteric fractures can be challenging and sometimes the clinical situation does not allow perfect implant positioning. The aim of this study was (1) to compare in human cadaveric femoral heads the biomechanical competence of two recently launched cephalic implants inserted in either an ideal (centre-centre) or less-ideal anterior off-centre position, and (2) to investigate the effect of bone cement augmentation on their fixation strength in the less-ideal position. Materials and Methods: Fourty-two paired human cadaveric femoral heads were assigned for pairwise implantation using either a TFNA helical blade or a TFNA screw as head element, implanted in either centre-centre or 7 mm anterior off-centre position. Next, seven paired specimens implanted in the off-centre position were augmented with bone cement. As a result, six study groups were created as follows: group 1 with a centre-centre positioned helical blade, paired with group 2 featuring a centre-centre screw, group 3 with an off-centre positioned helical blade, paired with group 4 featuring an off-centre screw, and group 5 with an off-centre positioned augmented helical blade, paired with group 6 featuring an off-centre augmented screw. All specimens were tested until failure under progressively increasing cyclic loading. Results: Stiffness was not significantly different among the study groups (p = 0.388). Varus deformation was significantly higher in group 4 versus group 6 (p = 0.026). Femoral head rotation was significantly higher in group 4 versus group 3 (p = 0.034), significantly lower in group 2 versus group 4 (p = 0.005), and significantly higher in group 4 versus group 6 (p = 0.007). Cycles to clinically relevant failure were 14,919 ± 4763 in group 1, 10,824 ± 5396 in group 2, 10,900 ± 3285 in group 3, 1382 ± 2701 in group 4, 25,811 ± 19,107 in group 5 and 17,817 ± 11,924 in group 6. Significantly higher number of cycles to failure were indicated for group 1 versus group 2 (p = 0.021), group 3 versus group 4 (p = 0.007), and in group 6 versus group 4 (p = 0.010). Conclusions: From a biomechanical perspective, proper centre-centre implant positioning in the femoral head is of utmost importance. In cases when this is not achievable in a clinical setting, a helical blade is more forgiving in the less ideal (anterior) malposition when compared to a screw, the latter revealing unacceptable low resistance to femoral head rotation and early failure. Cement augmentation of both off-centre implanted helical blade and screw head elements increases their resistance against failure; however, this effect might be redundant for helical blades and is highly unpredictable for screws.

Comparison of Helical Blade Systems for Osteoporotic Intertrochanteric Fractures Using Biomechanical Analysis and Clinical Assessments.

Background and Objectives: This study aimed to compare the biomechanical properties and outcomes of osteoporotic intertrochanteric fractures treated with two different helical blade systems, the trochanteric fixation nail-advanced (TFNA) and proximal femoral nail antirotation II (PFNA), to evaluate the efficacy and safety of the newly introduced TFNA system. Materials and Methods: A biomechanical comparison of the two helical blades was performed using uniaxial compression tests on polyurethane foam blocks of different densities. The peak resistance (PR) and accumulated resistance (AR) were measured during the 20 mm advancement through the test block. For clinical comparison, 63 osteoporotic intertrochanteric fractures treated with TFNA were identified and compared with the same number of fractures treated with PFNA using propensity score matching. Ambulatory status, medial migration, lateral sliding, fixation failure, and patient-reported outcomes were compared between the two groups over a minimum of 1 year's follow up. Results: The uniaxial compression test showed that a slightly, but significantly lower resistance was required to advance the TFNA through the test block compared with the PFNA (20 PCF, p = 0.017 and p = 0.026; 30 PCF, p = 0.007 and p = 0.001 for PR and AR, respectively). Clinically, the two groups showed no significant differences in post-operative ambulatory status and patient-reported outcomes. However, in TFNA groups, significantly more medial migration (TFNA, 0.75 mm; PFNA, 0.40 mm; p = 0.0028) and also, lateral sliding was noted (TFNA, 3.99 mm; PFNA, 1.80 mm; p = 0.004). Surgical failure occurred in four and two fractures treated with the TFNA and PFNA, respectively. Conclusions: The results of our study suggest that the newly introduced TFNA provides clinical outcomes comparable with those of the PFNA. However, inferior resistance to medial migration in the TFNA raises concerns regarding potential fixation failures.

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.

Conventional versus helical blade screw insertion following the removal of the femoral head screw: a biomechanical evaluation using trochanteric gamma 3 locking nail versus PFN antirotation.

OBJECTIVE: When a hip screw needs to be changed, choosing between the conventional (C-type) and helical blade (H-type) types is difficult. In this biomechanical study, we compared these two screw types relative to the type of the initial screw used. METHODS: C- or H-type screws were inserted (leading screw) in three types of polyurethane bone models (Sawbone, Pacific Research Laboratories, Inc., Washington, USA: 130 × 180 × 40 mm) of different bone mineral densities (pounds per cubic feet [PCF] 5, 80 kg/m3; PCF 10, 160 kg/m3; and PCF 15, 240 kg/m3), and then successively or alternately inserted (following screw) after the leading screw removal. An original model (original C and H) of a leading screw without removal was created as a control. The strengths of resistance to pullout (PO) and rotational stress were measured. For each experimental condition, there were 30 experimental models. RESULTS: The original C screw was superior in PO strength, and the original H-type screw was superior in rotational strength. When the C- or H-type screw was the leading screw, using the C-type screw again as the following screw (C1-C2, H1-C2) showed the greatest resistance to PO, and using the H-type screw as the following screw (C1-H2, H1-H2) showed superior resistance to rotational strength. However, the rotational strength of the C2 screw decreased by more than 50% compared with that of the original C screw. Moreover, the PO and rotational strengths of the H2 screw decreased to less than 30% overall compared with those of the original H screw. CONCLUSION: The H-type screw should be used for second-time screw insertion procedures in cases where it is difficult to choose between PO and rotational strengths.

Reverse total shoulder arthroplasty using helical blade to optimize glenoid fixation and bone preservation: preliminary results in thirty five patients with minimum two year follow-up.

PURPOSE: Glenoid loosening is a common cause of reverse total shoulder arthroplasty (RTSA) failure, and grafting of the glenoid is often required for revision due to bone loss due to the central peg in most glenoid baseplates. Helical blades have been used in the hip to optimize bone fixation in proximal femoral fracture. This study presents the initial results of specifically designed helical blade in the shoulder to optimize glenoid bone fixation and preservation as part of RTSA. METHODS: Thirty-five patients underwent RTSA with glenoid helical blade fixation. An uncemented glenoid baseplate was used with a central helical blade partially coated with hydroxyapatite and two or three screws. Outcome analysis was performed pre-operatively and at two years. RESULTS: All patients were satisfied with the results and significant improvement was observed in functional outcome scores between baseline and final follow-up. There was a single intra-operative undisplaced glenoid fracture which did not compromise the baseplate fixation. There was no radiographic evidence of loosening or radiolucencies around the helical blade. CONCLUSIONS: The helical blade provides a satisfactory primary fixation. Because of its length (21 mm), care should be taken in cases of pre-existing bone loss or sclerotic bone to avoid glenoid fracture or anterior cortical perforation. Helical blade has the potential to facilitate glenoid implant revision by preserving the glenoid bone stock.

Screw-blade fixation systems in Pauwels three femoral neck fractures: a biomechanical evaluation.

OBJECTIVES: To reduce mechanical complications after osteosynthesis of femoral neck fractures, improved fixation techniques have been developed including blade or screw-anchor devices. This biomechanical study compares different fixation systems used for treatment of unstable femoral neck fractures with evaluation of failure mode, load to failure, stiffness, femoral head rotation, femoral neck shortening and femoral head migration. METHODS: Standardized Pauwels type 3 fractures (AO/OTA 31-B2) with comminution were created in 18 biomechanical sawbones using a custom-made sawguide. Fractures were stabilized using either SHS-Screw, SHS-Blade or Rotationally Stable Screw-Anchor (RoSA). Femurs were positioned in 25 degrees adduction and ten degrees posterior flexion and were cyclically loaded with an axial sinusoidal loading pattern of 0.5 Hz, starting with 300 N, with an increase by 300 N every 2000 cycles until bone-implant failure occurred. RESULTS: Mean failure load for the Screw-Anchor fixation (RoSA) was 5100 N (IQR 750 N), 3900 N (IQR 75 N) for SHS-Blade and 3000 N (IQR 675 N; p = 0.002) for SHS-Screw. For SHS-Screw and SHS-Blade we observed fracture displacement with consecutive fracture collapse as the main reason for failure, whereas RoSA mainly showed a cut-out under high loadings. Mean stiffness at 1800 N was 826 (IQR 431) N/mm for SHS-Screw, 1328 (IQR 441) N/mm for SHS-Blade and 1953 (IQR 617) N/mm for RoSA (p = 0.003). With a load of 1800 N (SHS-Screw 12° vs. SHS-Blade 7° vs. RoSA 2°; p = 0.003) and with 2700 N (24° vs. 15° vs. 3°; p = 0.002) the RoSA implants demonstrated a higher rotational stability and had the lowest femoral neck shortening (p = 0.002), compared with the SHS groups. At the 2700 N load point, RoSA systems showed a lower axial (p = 0.019) and cranial (p = 0.031) femoral head migration compared to the SHS-Screw. CONCLUSIONS: In our study, the new Screw-Anchor fixation (RoSA) was superior to the comparable SHS implants regarding rotational stability and femoral neck shortening. Failure load, stiffness, femoral head migration, and resistance to fracture displacement were in RoSA implants higher than in SHS-Screws, but without significance in comparison to SHS-Blades.

Microalgal cultivation and hydrodynamic characterization using a novel tubular photobioreactor with helical blade rotors.

Industrial-scale microalgal cultivation for food, feedstocks and biofuel production is limited by several engineering factors, such as cultivation systems. As a closed microalgal growth system, tubular photobioreactors are the most preferred ones in the mass algae production. In this work, microalgal cultivation and hydrodynamic characterization using a novel tubular photobioreactor equipped with helical blade rotors (HBRs) were investigated, with the aid of computational fluid dynamics and cultivation experiments to evaluate the effect of HBRs on the performance of tubular photobioreactor and growth of the Chlorella sp. The results showed that the use of HBRs in tubular photobioreactors would result in swirl flow and increase of radial velocity and circumferential velocity; it also indicated that the HBRs would enable microalgal cells to move forward helically and to be shuttled alternatively between the light zone and the dark zone. This has led to the faster growth rate of Chlorella sp. and no attachment on the tube surface in the tubular photobioreactor during the whole cultivation cycle. In conclusion, the HBRs could improve the performance of tubular photobioreactors and thus impact positively on the cultivation of microalgae cells for biotechnological industry.

Early experience of dynamic hip screw with spiral blade and locking side plate for the stabilization of trochanteric fractures.

OBJECTIVE: To evaluate early experience with helical hip system in osteoporotic elderly patients with per-trochanteric fractures. METHODS: The retrospective study was conducted at Aga Khan University Hospital, Karachi, and comprised records of patients having low-velocity pertrochanteric fractures who were fixed with spiral blade Dynamic Helical Hip Systemfrom July to December 2014 and were followed up for a minimum of 3 months. Demographic variables and clinical outcomes were noted from the medical records whereas operative details were recorded from the operative note. Radiological variables and outcomes were assessed by viewing appropriate pre-operative, post-operative and follow-up radiographs. RESULTS: Of the 32 patients in the study, 14(44%) were men and 18(56%) were women, with an overall mean age of 77.81±7.04 years and mean body mass index of 25.99±4.13 kg/m2. Of the total, 1(3.13%) patient had implant cut-out, 1(3.13%) had myocardial infarctionand 2(6.2) expired. CONCLUSIONS: The introduction of spiral blade dynamic hip screw manifested favourable results and good clinical and radiological outcomes with low cut-out rates.

Intramedullary Femur Nailing in Intertrochanteric Fractures: Postoperatively Do Helical Blades Migrate More Than Lag Screws? A Randomized Controlled Trial.

Objectives: This was a prospective, randomized controlled trial to test functional outcomes between a single lag screw and helical blade nails in the treatment of intertrochanteric fractures. Methods: 72 patients with intertrochanteric fractures between March 2019 to November 2020 were randomized into two groups and treated with a lag screw or a helical blade nail. Intraoperative parameters such as operative time, blood loss, and radiation exposure were calculated. Postoperatively, tip apex distance, neck length, neck-shaft angle, lateral impingement of implant, union rate, and the functional outcomes were measured at the end of 6 month follow-up period. Results: There was a significant decrease in tip apex distance (p = 0.03) and neck length(p-0.04) with significant lateral impingement of the implant (p = 0.04) in the helical blade group compared to the lag screw group. The functional outcome calculated using the modified Harris Hip score & Parker and Palmer mobility score, at the end of 6 months, had no significant difference between the two groups. Conclusion: Both lag screw and helical blade devices can be used to successfully treat these fractures, although there is greater medial migration in the helical blade as compared to the lag screw.

[Femoral neck blade cut-in after internal fixation of a trochanteric femoral fracture with a TFNA©]. / "Schenkelhalsklingen-Cut-in" nach Osteosynthese einer pertrochantären Femurfraktur mittels TFNA©.

Following fixation of a trochanteric femoral fracture with a TFNA© and despite correct fracture reduction and fixation, a 96-year-old patient suffered a complete cut-in, i.e. a medialization of the entire femoral neck blade through the nail into the hip joint. Against the background of implant development and current literature, this increasingly frequent type of complication is described and distinguished from other fixation failures such as the cut-out. Attempts to explain this phenomenon as well as research options are presented and a pragmatic approach to avoid this problem is outlined.

The Effect of Bone Quality on Treatment of Intertrochanteric Fractures with Helical Blade Versus Lag Screw Fixation in Cephalomedulary Nails.

Introduction: The specific aim of this retrospective study was to determine whether bone quality has any effect on the complication rates or overall survivorship between helical blades and lag screws in cephalomedullary nails used for intertrochanteric hip fractures. Methods: The authors reviewed clinical charts and radiographic studies of patients between January 2012 and August 2019. We reviewed radiographic images (pre-, intra-, and post-operative) to evaluate fracture fixation type, fracture reduction grade, and post-operative complications. We collected dual energy x-ray absorptiometry scan results (T-score) and serum alkaline phosphatase (ALP) isoenzyme activity values to evaluate patient bone quality. Results: We included 303 cases (helical: 197, screw: 106) in the study. Complications were found in 31 (16%) helical blade cases and 23 (22%) lag screw cases. No statistically significant difference was detected when comparing complication rates with patient bone quality between the two groups. These two groups had similar one-year implant survivorship with respect to T-score, the low ALP level group, and normal ALP level group. The helical blade had higher implant survivorship compared to lag screw in five-year survival rate with respect to osteoporotic group, high ALP level group, and normal ALP level group (osteoporotic: 77% vs 69%, high ALP: 73% vs 67%, normal ALP: 70% vs 64%). Conclusions: Similar complication rates were observed between helical blade and lag screw constructs in cephalomedullary femoral nails when accounting for patient bone quality. However, the helical blade design had a higher five-year survival rate.

Blade Augmentation in Nailing Proximal Femur Fractures-An Advantage despite Higher Costs?

BACKGROUND: Proximal femoral fractures occur with increasing incidence, especially in the elderly. Commonly used implants for surgical treatment are cephalomedullary nails. To increase stability, a perforated femoral neck blade can be augmented with cement. The study investigated whether this results in a relevant clinical advantage and justifies the higher cost. MATERIALS AND METHODS: This is a single-center retrospective study of 620 patients with proximal femur fractures treated with cephalomedullary nailing. Between January 2016 and December 2020, 207 male and 413 female patients were surgically treated with a proximal femur nail (DePuy Synthes) using a perforated blade and cement augmentation in cases with severe osteoporosis. Primary outcome measures were the rate of cut-out, tip apex distance and the positioning of the blade in the femoral head. Secondary outcome measures were the implant costs and operating times. RESULTS: Of the 620 femoral neck blades, 299 were augmented with cement. A total of six cut-outs were seen in the first 3 months after the operation. There were three in the cement-augmented group (CAB = cement-augmented blade) and three in the conventional group (NCAB = non-cement-augmented blade). There was a significant positive correlation between age and augmentation, with a mean difference of 11 years between the two groups (CAB 85.7 ± 7.9 vs. NCAB 75.3 ± 15.1; p < 0.05). There was no difference in the tip-apex distance (CAB 15.97 vs. 15.69; p = 0.64) or rate of optimal blade positions between the groups (CAB 81.6% vs. NCAB 83.2%; p = 0.341). Operation times were significantly longer in the cemented group (CAB 62.6 21.2 min vs. NCAB 54.1 7.7 min; p < 0.05), and the implant cost nearly doubled due to augmentation. CONCLUSION: When the principles of anatomic fracture reduction, optimal tip-apex distance and optimal blade position are combined with cement augmentation in cases of severe osteoporosis, a cut-out rate of less than 1% can be achieved. Nevertheless, it should be noted that augmentation remains expensive and prolongs surgery time without definite proof of mechanical superiority.

[Reasons of the guide pin eccentricity of helical blade during proximal femoral nail anti-rotation internal fixation for femoral intertrochanteric fractures].

OBJECTIVE: To analyze the reasons and the influence of internal fixation about the guide pin eccentricity of helical blade during proximal femoral nail anti-rotation (PFNA) internal fixation for femoral intertrochanteric fractures. METHODS: A retrospective analysis of the intraoperative imaging data of 175 patients with femoral intertrochanteric fractures, who underwent closed reduction and PFNA internal fixation between January 2018 and January 2020, was performed. There were 76 males and 99 females with an average age of 79.8 years (mean, 61-103 years). The internal between admission and operation was 12-141 hours (median, 32 hours). According to AO/Orthopaedic Trauma Association (AO/OTA) classification, the fractures were rated as type 31-A1 in 64 cases and type 31-A2 in 111 cases. In the intraoperative fluoroscopy image by C-arm X-ray machine, the caputcollum-diaphysis (CCD) was measured after closed reduction and internal fixation, respectively; the angles between the center line of the head nail hole and the axis of proximal nail and between the axis of guide pin and proximal nail were measured, and the difference between the two angles was evaluated; the quality of fracture reduction was evaluated according to the alignment of the medial cortex, anterior cortex of the head and neck bone block, and femoral shaft cortex; the position of the helical blade in the femoral head was evaluated according to the Cleveland method. RESULTS: The CCDs of proximal femur were (134.6±6.8)° after closed reduction and (134.9±4.3)° after internal fixation. There was no significant difference between pre- and post-internal fixation ( t=0.432, P=0.766). The angles between the center line of the head nail hole and the axis of proximal nail and between the axis of guide pin and proximal nail were (125.4±2.44)° and (126.3±2.3)°, respectively, showing significant difference ( t=2.809, P=0.044). The difference between the two angles was (0.8±2.2)°. The guide pin eccentricity of helical blade occurred in 47 cases. After tapping the helical blade along the eccentric guide pin, 10 cases had fracture reduction loss, and 5 cases had a poor position of the helical blade in the femoral head. CONCLUSION: During PFNA internal fixation, a variety of reasons can lead to the eccentric position of the guide pin of helical blade, including unstable fracture, soft tissue inserted, severe osteoporosis, mismatched tool, and fluoroscopic imaging factors. It is possible that the fracture end would be displaced again and the helical blade position may be poor when knocking into the helical blade along the eccentric guide pin. During operation, it should be judged whether the direction of the guide pin needs to be adjusted according to the eccentric angle.

Comparison of sliding distance of lag screw and nonunion rate according to anteromedial cortical support in intertrochanteric fracture fixation: A systematic review and meta-analysis.

INTRODUCTION: We compared the sliding distance of the lag screw, change in neck-shaft angle (NSA), and nonunion rates according to the anteromedial cortical support on anteroposterior (AP) and lateral view radiographs post intertrochanteric fracture reduction. MATERIAL AND METHODS: In this systematic review and meta-analysis, MEDLINE, Embase, and Cochrane Library databases were searched systematically for studies published before September 26, 2020. We performed synthetic analyses of the amount of lag screw sliding, change in NSA, and incidence of nonunion following reduction of intertrochanteric fractures by extramedullary reduction (EMR), neutral reduction (NR), and intramedullary reduction (IMR). The combined data of EMR and NR comprised the non-IMR group. RESULTS: Our study enrolled eight studies, representing 1,363 patients who underwent surgery for intertrochanteric fractures. A pooled analysis showed a larger sliding distance in the IMR group than in the non-IMR group (standard mean difference [SMD] = 1.47, 95% confidence interval [CI]: 0.73-2.20; P < 0.0001 and SMD = 1.27, 95% CI: 0.56-1.99; P = 0.0005, respectively) in both AP and lateral views. The pooled mean difference of change in NSA in the IMR group was -3.11° and differed significantly from that of the non-IMR group (95% CI: -4.07 to -2.16; P < 0.0001). In the lateral view, the nonunion rate was significantly higher in the IMR group than in the non-IMR group (odds ratio [OR] = 11.61; 95% CI, 3.32-40.62; P = 0.0001). In the subgroup analysis, the NR group showed a larger sliding distance than that of the EMR group in the AP view (SMD = 0.40, 95% CI: 0.04-0.76; P = 0.03); however, the reverse was true in the lateral view (SMD = 0.68, 95% CI: 0.38-0.97; P < 0.00001). CONCLUSION: In the current meta-analysis, larger sliding distances, more varus in NSA, and higher nonunion rates were observed in the IMR group than the non-IMR group, in both AP and lateral views. However, in the comparison between EMR and NR, it was difficult to conclude which of them was the ideal reduction method because of inconsistent results.

Does the fracture of the lateral wall affect the degree of collapse and the degree of sliding of the cephalic plate, in pertrochanteric fractures treated by intramedullary interlocking? Radiological study and review of the literature. / ¿Afecta la fractura de la pared lateral al grado de colapso y al grado de deslizamiento de la lámina cefálica, en fracturas pertrocantéreas tratadas mediante enclavado intramedular? Estudio radiológico y revisión de la literatura.

BACKGROUND: Lateral wall fracture has been recognized as an important sign of instability of pertrochanteric fractures. The aim of the present study is to assess the relationship between lateral wall fractures, helical blade telescoping and neck shortening in fractures treated with intramedullary nailing. MATERIAL AND METHOD: A descriptive radiological study was performed at our institution. Patients who suffered a pertrochanteric fracture, treated at Hospital 12 de Octubre by intramedullary nailing were included. All fractures were classified according to Evans and AO systems. Preoperative and postoperative radiological assessment was carried out including a lateral wall fracture classification, helical blade telescoping and femoral neck shortening. RESULTS: 210 patients were included, 48% had a fracture of the femoral lateral wall. Helical blade telescoping was higher in lower lateral wall fractures with respect to higher fractures. Difference was statistically significant (p<0.05). Neck shortening was higher in fractures with femoral lateral wall disruption; despite not have found any significant differences comparing to fractures with intact lateral wall (P=.39). Multivariate analysis showed statistically significant association between helical blade telescoping, neck shortening and lateral wall fracture. CONCLUSIONS: There is evidence of a higher helical blade telescoping and neck shortening in pertrochanteric fractures with lateral wall fracture treated with intramedullary nails, especially in those with most unstable patterns such us fractures of the lateral wall distal to the vastus ridge.

An alternative method to tighten the helical blade with impaired locking mechanism during operation of cephalomedullary nailing.

During the operation of proximal femoral nail antirotation (PFNA), surgeons may run across a rare problem that the helical blade fails to be tightened and locked by clockwise turning of the impactor handle. At this moment, three options can be taken: first, replace the unlocked helical blade and re-insert another new one; second, keep the unlocked helical blade in place, proceed and finish the operation as usual; and third, as we described, keep the first helical blade in situ and tighten and lock it by other instruments, such as the SW4.0 mm hexagonal screwdriver for the distal interlocking screw, which is already in the instrument box. The third option is the best, as it keeps the operation going and remains the fixation quality as usual.

TFNA Implant Failure with Helical Blade Cut-out.

INTRODUCTION: Trochanteric femoral nail-advanced (TFNA) was introduced in the market with better nail design, better alloy (titanium molybdenum) and both sliding and static locking options of the helical blade. Although, it was devised to overcome the shortcomings of roximal Femoral Nail Anti-rotation (PFNA), it still can have complications, if the principles of fracture management are not met. Here, we report a case of a TFNA implant failure with helical blade cut-out in an elderly osteoporotic patient treated for inter-trochanteric femur fracture. To the best of our knowledge, this is the first report of helical blade cut-out wit TFNA nail in world literature. CASE REPORT: An 83-year-old female patient was treated with a TFNA nail for inter-trochanteric femur fracture (AO 31A2.1). An acceptable reduction and stable fixation were achieved. The position of the helical blade in the head was in the optimal position with a tip apex distance (TAD) of 29 mm. The patient presented to us 6 weeks later with implant failure with helical blade cut out after a history of fall. Cemented bipolar hemiarthroplasty with calcar reconstruction using a mesh was done. The patient was clinically asymptomatic and was walking full weight-bearing till her last follow-up at 14 months. CONCLUSION: We can associate the failure seen in our case with an increased TAD of 29 mm, osteoporotic bone and a neutral to negative variance. Helical blade cut-out was seen as the blade was locked onto the nail with insufficient hold onto the osteoporotic head fragment which collapsed into varus, leading to cut-out. This case report emphasizes the importance of TAD, valgus reduction, and positive variance in avoiding implant failures, even with a newer implant like TFNA which was developed to improvise onto the shortcomings of PFNA nail.

Outcome of Proximal Femoral Nail Antirotation II fixation of Peritrochanteric Fracture of Femur.

BACKGROUND: Intramedullary fixation is biomechanically superior to extramedullary fixation for fracture of peritrochanteric region of femur in elderly which is often complicated due to associated osteoporosis. Helical blade of proximal femoral nail antirotation II has stronger purchase in the head of femur preventing rotation and cutout. This study was done to evaluate the outcome of Proximal Femoral Nail Antirotation II fixation in B.P. Koirala Institute of Health Sciences. METHODS: Retrospective review of the data of 100 traumatic peritrochanteric fracture cases operated between March 2017 and March 2018 was done for study. Cases lost to follow-up, deaths and incomplete functional outcome (VAS, HHS), intraoperative and postoperative data were excluded. Total of 71 cases were included in the study. RESULTS: Mean age of patients was 65 (+14) (range:19 to 86) years and were operated for intertrochanteric (54), subtrochanteric (16) and neck of femur (1) fractures. Trivial fall on ground was the commonest mechanism of injury (43 of 71). Mean injury to surgery time was 7 (+7) days and mean duration of hospital stay was 5.92 (+4) days. Mean blood loss during surgery was 132.61 (+21) ml and mean surgical time was 56 (+8) minutes. Mean visual analogue scale (VAS) Score was 7 at 2 weeks, 3 at 6 weeks and 1 at 12 weeks. Mean harris hip score was 80 (+10) at 6 months. CONCLUSIONS: Proximal femoral nail antirotation II is a reliable implant system to use for fixation of proximal femoral fractures with a good functional outcome and low complication rates.