Hybrid screw fixation for femoral neck fractures: Does it prevent mechanical failure?

IntroductionTraditionally, femoral neck fracture fixation has been performed using three partially threaded cancellous screws. However, fracture collapse with femoral neck shortening, and varus deformation frequently occurs due to posterior medial comminution and lack of calcar support. We hypothesize replacing the inferior neck/calcar screw with a fully threaded, length stable, screw will provide improved biomechanical stability, decrease femoral neck shortening and varus collapse.MethodsTen matched cadaveric pairs (20 femurs) were randomly assigned to two screw fixation groups. Group 1 (Hybrid) utilized one fully threaded calcar screw & two partially threaded superior screws. Group 2 (PT) utilized all partially threaded screws. Specimens underwent standardized femoral neck osteotomies, 45° from the horizontal, with 5 mm posteromedial wedge removed to simulate posteromedial comminution. Screws were placed using fluoroscopic guidance. Specimens were biomechanically tested using two loading sequences: 1) Axial load applied up to 700 N, followed by cyclic loading at 2 Hz with loads of 700 to 1,400 N for 10,000 cycles. 2) All surviving constructs were cyclically loaded to failure in stepwise incremental manner with max load of 4,000 N. Paired t-tests used to compare stiffness, cycles to failure, and max load to failure (defined as 15 mm load actuator displacement).ResultsConstruct stiffness was 2848 ± 344 N/mm in PT vs. 2767 ± 665 for Hybrid (P = 0.628). Load to failure demonstrated, hybrid superiority with max cycles to failure (3797 ± 400 cycles) vs. (2981 ± 856 cycles in PT) (p = 0.010), and max load prior to failure (3290 ± 196 N) vs. (2891 ± 421 N in PT) (p = 0.010). No significant difference in bone mineral density was noted in any of the specimens.ConclusionsOur study is the first to assess the biomechanical effects of hybrid fixation for femoral neck fractures. Hybrid screw configuration resulted in significantly stronger constructs, with higher axial load and increased cycles prior to failure. The advantageous mechanical properties demonstrated using a fully threaded inferior calcar screw provides a length stable construct which may prevent the common complication of excessive femoral neck shortening, varus collapse and poor functional outcome.     

Ideal screw positions for multiple screw fixation in femoral neck fractures – Study of proximal femur morphology in a Japanese population

Background

Despite the fact that multiple screw fixation is a common option of surgical treatment for femoral neck fractures, there is a paucity of precise morphological study of the femoral neck. To identify appropriate positions and spacing of hip screws for multiple-screw femoral neck fracture fixation, proximal femur morphology in Japanese patients was studied.

Unipolar or bipolar hemiarthroplasty for femoral neck fractures in the elderly?

This prospective randomized trial compared the efficacy of unipolar versus bipolar hemiarthroplasty in elderly patients (> or = 65 years) with displaced femoral neck fractures in terms of quality of life and functional outcomes. One hundred fifteen patients with a mean age of 82.1 years were enrolled in this study and randomized to either unipolar or bipolar hemiarthroplasty. Quality of life and functional outcomes were assessed using the Musculoskeletal Functional Assessment instrument and Short Form-36 health survey. Seventy-eight patients completed 1 year of followup. There were no differences between the groups in estimated blood loss, length of hospital stay, mortality rate, number of dislocations, postoperative complications, or ambulatory status at 1 year. There also were no significant differences between the two groups at either point in postoperative Short Form-36 or Musculoskeletal Functional Assessment instrument scores. Results of this prospective randomized study suggest that the bipolar endoprosthesis provides no advantage in the treatment of displaced femoral neck fractures in elderly patients regarding quality of life and functional outcomes.     

Internal fixation for displaced fractures of the femoral neck. Does bone density affect clinical outcome?

The results of meta-analysis show a revision rate of 33% for internal fixation of displaced fractures of the femoral neck, mostly because of nonunion. Osteopenia and osteoporosis are highly prevalent in elderly patients. Bone density has been shown to correlate with the intrinsic stability of the fixation of the fracture in cadaver and retrospective studies. We aimed to confirm or refute this finding in a clinical setting. We performed a prospective, multicentre study of 111 active patients over 60 years of age with a displaced fracture of the femoral neck which was eligible for internal fixation. The bone density of the femoral neck was measured pre-operatively by dual-energy x-ray absorptiometry (DEXA). The patients were divided into two groups namely, those with osteopenia (66%, mean T-score -1.6) and those with osteoporosis (34%, mean T-score -3.0). Age (p = 0.47), gender (p = 0.67), delay to surgery (p = 0.07), the angle of the fracture (p = 0.33) and the type of implant (p = 0.48) were similar in both groups. Revision to arthroplasty was performed in 41% of osteopenic and 42% of osteoporotic patients (p = 0.87). Morbidity (p = 0.60) and mortality were similar in both groups (p = 0.65). Our findings show that the clinical outcome of internal fixation for displaced fractures of the femoral neck does not depend on bone density and that pre-operative DEXA is not useful.     

Two or three screws for fixation of femoral neck fractures?

This study compares the stability of 3 cannulated cancellous lag screws with that of 2 cannulated cancellous lag screws for fixation of subcapital femoral neck fractures. Using 10 matched pairs of human cadaveric femurs, subcapital femoral neck osteotomies were created, reduced, and then randomized to 1 of the 2 fixation methods. The constructs were tested with anterior loading to 500 N, incremental axial loading from 100 N to 1000 N, and cyclic loading at 1000 N. The specimens stabilized using 3 screws showed greater resistance to anterior loading, less inferior femoral head displacement, and less superior gapping at the osteotomy site. Although 2 screws may be an acceptable fixation method for this fracture type, the addition of a third screw provides supplemental stability and appears justified.     

High incidence of “in–out–in” posterosuperior screws after cannulated screw fixation of femoral neck fractures

European Journal of Orthopaedic Surgery & Traumatology - Cadaveric models have demonstrated a high incidence of extraosseous “in–out–in” (IOI) posterosuperior screws...     

Prosthetic replacement in treatment of subcapital femoral neck fractures in the elderly

OBJECTIVE: To compare the results of femoral head replacement (FHR) and total hip replacement (THR) in treatment of subcapital femoral neck fractures (SFNF). METHODS: Between May 1987 and July 1998, 56 elderly patients (6 5-90 years; average 73.5 years) with SFNF were treated with prosthetic replacement. Six cases were treated with unipolar FHR, 18 cases with Bateman bipolar FHR, and 32 cases with Bateman bipolar THR. All domestic prostheses were installed with cement. RESULTS: There was no significant difference between the 2 groups in operating time and blood transfusion. Forty-nine patients were followed-up for an average of 5 years and 10 months. No wound infection or death was related to surgery. Complications in Group FHR were significantly higher than that i n Group THR. CONCLUSIONS: Since FHR is difficult to fit the bony acetabulum, it is only indicated for senile cases with poor conditions. However, the bi polar THR installed with cement is indicated for most elderly patients. Since th e femoral head and acetabulum can fit each other completely, it is more stable for taking weight-bearing earlier with less complications.     

Miniarthrotomy assisted percutaneous screw fixation for displaced medial malleolus fractures – A novel technique

Aim

To describe here a technique of miniarthrotomy assisted percutaneous screw insertion for displaced Herscovici type B and C medial malleolar fractures.

Method

Incision was made centred over the superomedial angle of the ankle mortise, about half a cm medial to tibialis anterior. Arthrotomy was done and reduction obtained. Percuntaneously, two 4 mm cancellous cannulated screws were inserted through medial malleolus.

Results and conclusion

This approach allows direct visualization of reduction, removal of entrapped soft tissue and preservation of saphenous vein and nerve.     

Displaced femoral neck fractures: internal fixation or arthroplasty?

Femoral neck fractures are a challenge for orthopedic surgeon due to the high rate of complication for such fractures. The aim of this study was to propose a treatment algorithm based on author's current concept in management of femoral neck fractures. Fractures were classified according Garden in four types but, for practical reasons, fractures were considered undisplaced (Garden I and II) and displaced (Garden III and IV). Treatment method was chosen based on next criteria: patient's age, associated pathology, patient's mental status and expectations, quality of the bone (osteoporosis), type and age of fracture, quality of reduction. Based on this criteria, the proposal algorithm may led to close reduction and internal fixation, open reduction and internal fixation or arthroplasty.     

The anterior approach for the fixation of displaced talar neck fractures—A cadaveric study

BackgroundTalar neck fractures are rare and are associated with high complication rates. Adequate surgical exposure is essential in the operative management of these challenging injuries. The anterior approach is an alternative to the more commonly described and utilized anterolateral and anteromedial approaches.ObjectiveThe main objective was to compare the surface area of talus visible and quality of exposure via the anterior approach, with the anteromedial and anterolateral approaches.Materials and methodsAn anterior approach was performed on five fresh frozen cadaveric specimens. The surface area of talus visible was measured using an Immersion Digital Microscribe and analyzed with the Rhinoceros 3D graphics package. Standard anterolateral and anteromedial approaches were performed in the same specimens and areas visible measured using the same method.ResultsThe talar surface area visible using the anterior approach is significantly greater than that visible using the anterolateral approach or anteromedial, without and with medial malleolar osteotomy, as well as combination approaches.ConclusionThe anterior approach offers excellent visualization in the fixation of displaced talar neck fractures. Greater talar surface area is visible using this approach compared to traditional approaches.     

Factors associated with avascular necrosis of the femoral head and nonunion in patients younger than 65 years with displaced femoral neck fractures treated with reduction and internal fixation

Introduction

Few studies have evaluated treatment of displaced femoral neck fractures in patients younger than 65 years, and risk factors for AVN or nonunion have not been clearly delineated within this age range.

Method

To determine factors associated with avascular necrosis of the femoral head (AVN) and nonunion in patients younger than 65 years with displaced femoral neck fractures treated with reduction and internal fixation, we conducted a retrospective study of 29 displaced femoral neck fractures in 29 consecutive patients treated at a single institution. The influence of age, trauma energy, open reduction, and time from fracture to treatment on development of AVN and nonunion was evaluated.

Results

Patients who developed AVN were significantly older and suffered lower energy trauma than cases without AVN. No recorded variables were associated with nonunion. Logistic regression determined that only age was independently associated with AVN. Age was a good predictor for developing AVN, with a C statistics of 0.861, and a best cutoff determined at 53.5 years.

Conclusion

Patients between 53.5 and 65 years presented a higher risk of AVN. A primary arthroplasty should be considered in this subgroup.     

Functional outcome of modified Pauwels�� intertrochanteric osteotomy and total hip arthroplasty in femoral neck fractures in elderly patients

Background:

A high union rate (75%-100%) with a lower incidence of avascular necrosis (8%-9.3%) has been reported with intertrochanteric osteotomy in femoral neck fractures in elderly whereas arthroplasty eliminates the incidence of nonunion and avascular necrosis We present a series of femoral neck fracture in elderly treated with modified Pauwels’ intertrochanteric osteotomy and total hip arthroplasty for their functional outcome.

Materials and Methods:

29 elderly patients of 60 years and above sustaining fresh subcapital femoral neck fracture underwent total hip arthroplasty (group I, n=14) and modified Pauwels’ intertrochanteric osteotomy (group II, n=15). Functions were evaluated using modified Harris hip score, d''Aubigne and postel criteria and SF-36 score at 6, 12, 52 and 100 weeks.

Results:

The fracture union in group II was achieved in 14 (93.3%) patients at the fracture site at an average of 15 weeks and osteotomy united in all patients. Avascular necrosis of the femoral head was observed in one patient (6.7%). Average operative time was 88.9 and 65.6 minutes in group I and II, respectively (P value = 0.00001). An average of 0.8 and 0.2 unit blood was transfused in patients in group I and II, respectively (P value = 0.001). Average time of full weight bearing was 6.1 weeks and 11.6 weeks in group I and group II, respectively. At 100 weeks 71.4% (n = 10) patients in group I and 80% (n = 12) patients in group II showed good to excellent results on the basis of modified Harris hip score. 71.4% (n = 10) patients in group I and 66.6% (n = 10) patients in group II showed good to excellent results on the basis of d''Aubigne criteria. Average SF-36 score was 17.2% in group I and 17.6% in group II. Revision osteotomy was performed in one patient in group II because of implant cut through. Another patient in group II underwent THR because of painful hip. One patient in group I presented with dislocation after 3 weeks of surgery.

Conclusion:

Functional results of total hip arthroplasty and intertrochanteric osteotomy are comparable and the valgus intertrochanteric osteotomy with osteosynthesis in subcapital femoral neck fractures in elderly patients of sixty years and above may be considered as an option.     

“No high tech”: a new, non-invasive technique for accurate guide wire placement in the dynamic hip screw fixation of femoral neck fractures

Placement of the guide wire in the dynamic hip screw operation can be a challenging task to the trauma surgeon. Complications can arise related to incorrect guide wire entry point, making multiple wrong tracks or even accepting an unsatisfactory lag screw placement. Insisting to optimise the guide wire position can lead to increase in operation time and radiation exposure time. A new, non-invasive technique is described to assist precision placement of the guide wire in the dynamic hip screw fixation of femoral neck fractures using no more than a size A4 plain folded paper and a non-permanent marker pen. The new, non-invasive, no-high-tech method can help trauma surgeons shorten the operation time and reduce the radiation exposure time needed to place the guide wire in the dynamic hip screw fixation of femoral neck fractures.     

Fixation of displaced femoral neck fractures in young adults: Fixed-angle devices or Pauwel screws?

BackgroundWe sought to compare the incidence of complications after fixation of displaced femoral neck fractures in young adults treated with fixed-angle devices versus multiple cancellous screws and a trochanteric lag screw (Pauwel screw).MethodsWe conducted a retrospective cohort study at a level I trauma centre. Sixty-two skeletally mature patients (age range, 16–60 years) with displaced femoral neck fractures were included in the study. Forty-seven were treated with a fixed-angle device (sliding hip plate with screw or helical blade) and 15 with multiple cancellous screws placed in a Pauwel configuration. The main outcome measure was postoperative complication of osteonecrosis or nonunion treated with a surgical procedure.ResultsSignificantly fewer failures occurred in the fixed-angle group (21%) than in the screws group (60%) (p = 0.008). Osteonecrosis was rare in the fixed-angle group, occurring in 2% of cases versus 33% of cases in the screws group (p = 0.002). Consistent with previous studies, good to excellent reductions were associated with a failure rate of 25% and fair to poor reductions were associated with a failure rate of 55% (p = 0.07). The best-case scenario of a good to excellent reduction stabilised with a fixed-angle device yielded a success rate of 85%.ConclusionIn young patients with displaced high-energy femoral neck fractures, fixed-angle devices resulted in fewer treatment failures than did Pauwel screws.     

Is external fixation in pediatric femoral fractures a risk factor for refracture?

The aim of this study was to investigate whether external fixation is a risk factor for refracture by comparing the outcomes of children who received three different forms of treatment of femoral fractures. One hundred ninety-two patients treated for femoral fracture between 1990 and 1999 who underwent final examination were assessed. One hundred were treated with hip spica casting after traction, 57 with closed reduction and external fixation, and 35 with open reduction and external fixation. Morbidity results such as time to union, length of hospital stay, refracture, and wire site infection were statistically evaluated. Patients undergoing open reduction had a greater time to union and length of hospital stay and a higher refracture rate. The difference was statistically significant. Wire site infection occurred in all three groups; there was no statistically significant difference between groups. The authors concluded that external fixation is not a risk factor for refracture in the treatment of pediatric closed femoral diaphyseal fractures, and that it may be used with ease in clinics with shortages of personnel and space.     

Valgus intertrochanteric osteotomy with single-angled 130° plate fixation for fractures and non-unions of the femoral neck

Non-union of femoral neck fractures may occur due to mechanical and biological factors. Valgus intertrochanteric osteotomy (VITO) alters hip biomechanics and enhances fracture union. The double-angled 120° plate is usually used for internal fixation of the osteotomy. It allows the osteotomy to heal with medialisation and verticalisation of the femoral shaft. This deformity causes medial ligament strain of the knee joint, genu valgum and ultimately osteoarthritis. This work presents our experience in treating vertical fractures and non-unions of the femoral neck by VITO and fixation by a single-angled 130o plate. Thirty-six patients presented with 19 recent vertical femoral neck fractures, and 17 non-unions were included. They were 26 men and ten women, and their ages averaged 37 years. Preoperative planning and VITO technique are described. Union was achieved in 35 patients (97%), and one recent fracture failed to unite (3%). Time to fracture union averaged four months in recent fractures and eight months in un-united fractures. All patients with united fractures had an almost normal configuration of the upper femur. Avascular necrosis of the femoral head was reported in five patients. Twenty-two patients (61%) were pain free, nine (25%) had hip pain on lengthy walks and the remaining five (14%) had persistent pain. Preoperative limb shortening averaged 2.5 cm, and post-operative shortening averaged 0.5 cm. We recommend VITO and fixation by a single-angled 130o plate for vertical femoral neck fractures and non-unions in relatively young adult patients.     

Functional comparison between uncemented Austin-Moore hemiarthroplasty and osteosynthesis with three screws in displaced femoral neck fractures—a matched-pair study of 168 patients

There is no consensus as to whether osteosynthesis (OS) or hemiarthroplasty (HA) should be used as the primary treatment of displaced femoral-neck fracture. In a prospective matched-pair study, we compared 84 patients treated with OS with three screws and 84 patients treated with uncemented Austin-Moore HA focusing on functional parameters, reoperations and mortality. At 4 months after the fracture, functional recovery was not significantly different between the study groups. However, OS patients tended to have slightly better functional ability than HA patients, as more of them were able to walk out of doors (45.2% versus 39.2%), more were able to walk without walking aids (23.7% versus 16.7%), and more returned to live in their own homes (80%versus 72.9%). OS patients used slightly but not significantly less painkillers and had less hip pain than HA patients. OS patients had had 15.4% more reoperations by 4 months and 14.2% more by 1 year compared to the HA group. The 4-month and 1-year mortality rates of the study groups were of the same order. Functional recovery was slightly better after OS with three screws than after uncemented HA, although no significant differences were seen in a sample of this size. On the other hand, OS was associated with a higher reoperation rate.

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Résumé Il ny a aucun consensus sur le traitement initial de la fracture déplacée du col fémoral entre ostéosynthèse (OS) ou hémiarthroplastie (HA). Dans une étude prospective appariée avec focalisation sur les paramètres fonctionnels, les réinterventions et la mortalité, nous avons comparé 84 malades traités par OS avec trois vis et 84 malades traités par HA de type Austin Moore non cimentée. Quatre mois après la fracture, la récupération fonctionnelle nétait pas significativement différente entre les deux groupes de létude. Cependant, les malades OS avaient tendance à avoir une meilleure fonction que les malades HA, avec une meilleure possibilité de marche à lextérieur (45,2% contre 39,2%), de marche sans aide (23,7% contre 16,7%), et plus de retour à domicile (80% contre 7,9%). Les malades OS utilisaient, mais de façon non significative, moins dantalgiques que les malades HA et avaient moins de douleurs de hanche. Les malades OS avaient 15,4% de plus de ré-opérations à 4 mois et 14,2% dans lannée, comparés au groupe HA. Le taux de mortalité à quatre mois et à un an était du même ordre dans les deux groupes. La récupération fonctionnelle est légèrement meilleure après OS avec trois vis quaprès HA non cimenté, bien quaucune différence significative nait été relevée dans cet échantillon. En revanche, OS est associé à un taux supérieur de réinterventions.

     

Incidence and risk factors for failure of conservative treatment for valgus impacted femoral neck fractures in elderly patients with high-risk comorbidities–A bi-center retrospective observational study

Background–Establishing the ideal indications for conservative treatment for elderly patients with valgus impacted femoral neck fractures is difficult because few studies have identified predictive factors for the failure of this treatment method. This study aimed to report the outcomes of conservative treatment for elderly patients with valgus impacted femoral neck fractures and determine risk factors that lead to treatment failure.Methods–From January 2009 to December 2018, 206 patients with valgus impacted femoral neck fracture were identified at two institutions. Elderly patients with valgus impacted femoral neck fractures corresponding to an Orthopedic Trauma Association/AO Foundation (OTA/AO) classification of 31-B1.1 or 31-B1.2 who were treated conservatively were included in the study. The following data was collected to compare the preoperative characteristics of patients with valgus impacted femoral neck fractures: age, sex, bone mineral density, medical comorbidities (hypertension, diabetes mellitus, ischemic heart disease, arrhythmia, chronic kidney disease [CKD], and stroke), medial cortex displacement, valgus angle, posterior tilt, and retroversion. These data were used to assess the independent predictors for failure of conservative treatment using multiple logistic regression analysis.Results–The failure rate after conservative treatment for valgus impacted femoral neck fracture in the enrolled patient group was 27.3% (15 of 55). CKD, presence of medial cortex displacement, high posterior tilt, and high retroversion were all identified as independent predictors for failure. The cut-off values for retroversion and posterior tilt that predicted treatment failure were 12.5° (area under curve [AUC] 0.768, p = 0.002, 95% confidence interval [CI] 0.632–0.903, sensitivity 0.733, 1-specificity 0.300) and 7.5° (AUC 0.712, p = 0.016, 95% CI 0.542- 0.881, sensitivity 0.667, 1-specificity 0.325), respectively.Conclusions–The present study showed that a high union rate could be obtained if the indications for conservative treatment in for elderly patients with valgus impacted femoral neck fractures are well-defined. Thus, we believe that conservative treatment can be a viable option for valgus impacted femoral neck fractures when elderly patients with high-risk comorbidities have acceptable fracture angulation, no medial cortex displacement, and no CKD.Level of Evidence–Level III, retrospective cohort study.