Endosteal Biologic Augmentation for Surgical Fixation of Displaced Femoral Neck Fractures

Role of Fibular Allograft in Proximal Humerus Fractures: A Systematic Review

OBJECTIVES

To analyze the outcomes and complication rates of fibular allografts (FA) as an augmentation technique for proximal humeral fractures and determine their appropriate indications.

DATA SOURCES

English- and Spanish-language articles in PubMed, MEDLINE, Embase, Web of Science (Core Collection), and Google Scholar databases were systematically reviewed with the Preferred Reporting Items for Systematic Reviews guidelines on April 10, 2020.

STUDY SELECTION

Studies of patients with proximal humeral fractures treated primarily with FA and locking compression plates and with a minimum follow-up of 6 months were included, and presenting results with standardized clinical scales, radiological values, and operative complications.

DATA EXTRACTION

Two authors independently extracted data from the selected studies with a standardized data collection form. Subsequently, each extracted data set was consolidated on the agreement of authors.

DATA SYNTHESIS

From the initial screening of 361 articles, 5 case series and 6 retrospective cohort studies were included. A meta-analysis was not performed.

CONCLUSIONS

FA improved the clinical and radiological results, thereby reducing complications. The optimal indication for this procedure may be a 4-part fracture with medial column disruption in younger adults.

LEVEL OF EVIDENCE

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

Comparison between headless cannulated screws and partially threaded screws in femoral neck fracture treatment: a retrospective cohort study

The choices of the treatments for femoral neck fractures (FNF) remain controversial. The purpose of this study is to evaluate the prognoses of the variable pitch fully threaded headless cannulated screws (HCS) in the fixation of femoral neck fractures and to compare them with those of partially threaded cannulated screws (PCS). Between 1st January 2012 and 31st December 2016, there were 89 patients with the main diagnose of FNF who accepted the treatment of closed reduction cannulated screw fixation in Peking University People’s Hospital. 34 cases of PCS and 23 cases of HCS met the criterion. The characteristics, prognoses and the imaging changes of all cases were described and the differences between the two groups were compared. Statistical analyses were performed using SPSS version 23.0 (SPSS Inc., USA). Mann–Whitney U test, Analysis of Variance and Chi-square test were used. Statistical significance was defined as P value (two sided) less than 0.05. There was no significant difference in the general characteristics, fracture classifications and reduction quality between the two groups. HCS group had a significant lower angle decrease rate (30.4% vs. 58.8%, P = 0.035), femoral neck shortening rate (26.1% vs. 52.9%, P = 0.044) and screw back-sliding rate (21.7% vs. 50.0%, P = 0.032), but a higher screw cut-out rate (21.7% vs. 0.0%, P = 0.008). In non-displacement fracture subgroup, HCS had significant higher Harris Score (92 vs. 90, P = 0.048). Compared with PCS, HCS had a lower screw back-sliding rate, femoral shortening rate, angle decrease rate and similar function score, but would result in more screw cut-outs in displaced FNF. As a conclusion, HCS should not be used in displaced FNF due to its higher screw cut-out rate, and its potential advantage in non-displaced FNF needs to be further proved. Further qualified investigations with a larger scale of patients and longer follow-up are needed in the future.

[Treatment of unstable femoral neck fracture with posteromedial comminutations by cannulated screws and medial bracing plate combined with bone allograft]

Objective

To evaluate the effectiveness of unstable femoral neck fracture with posteromedial comminutations treated by cannulated screws and medial bracing plate combined with bone allograft.

Methods

The clinical data of 18 patients with unstable femoral neck fracture with posteromedial comminutations treated by cannulated screws and medial bracing plate combined with bone allograft between July 2016 and March 2020 were retrospectively analyzed. The age ranged from 22 to 64 years, with a median age of 43 years. The causes of injury included 11 cases of falling injury, 3 cases of traffic accident injury, and 4 cases of fall from height injury. According to Garden classification, the femoral neck fracture was classified as type Ⅲ in 3 cases, type Ⅳ in 15 cases, and all patients were type Ⅲ according to Pauwels classification. The time from injury to operation was 1-5 days, with an average of 2.3 days. The fracture healing time and complications were recorded. The quality of fracture reduction was evaluated by Garden index immediately after operation; at last follow-up, the degree of femoral neck shortening was determined by Zlowodzki method, Harris score was used to evaluate hip function.

Results

The operation time was 62-98 minutes (mean, 75 minutes); intraoperative blood loss was 101-220 mL (mean, 153 mL). Cannulated screws guide wire was inserted 3-5 times (mean, 4 times). Intraoperative fluoroscopy was performed 9-21 times (mean, 15 times). The hospital stay was 5-11 days (mean, 7.2 days). All the patients were followed up 12-40 months with an average of 17.3 months. There was no postoperative complication such as accumulated pneumonia, lower extremity deep venous thrombosis, nail cutting, nail withdrawal, internal fixation fracture, and so on. There was no fracture nonunion and osteonecrosis of the femoral head during the follow-up; the fracture healing time was 7-15 weeks, with an average of 12.1 weeks. The quality of fracture reduction was evaluated immediately after operation, the results were grade Ⅰ in 15 cases and grade Ⅱ in 3 cases. At last follow-up, there were 2 cases with femoral neck shortening less than 5 mm and 1 case with 5-10 mm. The incidence of femoral neck shortening was 16.7%. The Harris score of hip joint was 73-97, with an average of 93.5; among them, 12 cases were rated as excellent, 3 cases as good, and 3 cases as fair, with an excellent and good rate of 83.3%.

Conclusion

For the treatment of unstable femoral neck fracture with posteromedial comminutations, cannulated screws and medial bracing plate combined with bone allograft are dramatically effective due to earlier weight bearing, faster fracture healing, and better hip function recovery.

Endosteal substitution with medial plate in the treatment of acute distal femur fracture (AO/OTA type A): surgical technique and case-series

INTRODUCTION

Distal Femur fractures account for 4- 6% of all femur fractures and can be challenging to treat. The aims of this study are: (1) to describe a surgical technique using a medial distal femur endosteal plate to augment the stability of standard lateral plate fixation; (2) to report the results of a case-series of acute distal femur fractures (AO/OTA Type A/ Vancouver periprosthetic fractures Type C) treated using this technique.

METHODS

This study describes the surgical steps for placement of a medial endosteal plate in combination with lateral locking plate in a cadaver model using fluoroscopy guidance. In addition, a retrospective database chart review for all patients with acute distal femur fractures treated with this technique over the last five years was performed. Exclusion criteria were involvement of type B and C distal femur intraarticular fractures, treatment with other endosteal substitutions (i.e., intramedullary nail fixation and fibula allograft), and treatment for non-union or pathological fractures.

RESULTS

Twelve patients were identified with mean age of 75 years. All patients were female and all of them were allowed full weight bearing and full range of motion exercises immediately post-operatively. The complete follow up for one patient was not available; however, the mean fracture union was confirmed at 3.8 months in 10 of 12 patients. One patient had a failed construct at three months in the context of a periprosthetic fracture with a loose implant that was initially thought to be stable. One acute superficial surgical site infection was reported and healed uneventfully following debridement, primary closure, and antibiotic treatment.

CONCLUSION

We believe that the placement of a medial endosteal plate can be a useful augment for standard lateral plate fixation in acute distal femur fractures, particularly in the context of severe comminution or poor bone quality. Uneventful healing was confirmed in 10 of 12 cases and no patients were restricted with regard to motion or weight bearing immediately post-operatively. Further studies with larger sample size would be required to fully assess this technique.

LEVEL OF EVIDENCE

IV. Therapeutic Study (Surgical technique and Cases-series).

Failed Proximal Humerus Osteosynthesis Using Intramedullary Fibular Strut Allograft Conversion to Reverse Shoulder Arthroplasty

Comminuted proximal humerus fractures are more frequently being treated utilizing an intramedullary fibular strut allograft to assist with open reduction internal fixation. Although this technique has led to improved outcomes, avascular necrosis, rotator cuff failure, and/or prominent hardware may still occur necessitating conversion to reverse shoulder arthroplasty. The presence of an intramedullary strut allograft makes this conversion technically demanding and creates certain potential complications unique to this group. This manuscript details the conversion of a proximal humerus open reduction internal fixation with a fibular strut allograft to reverse shoulder arthroplasty including presurgical workup, surgical techniques, and pitfalls for undertaking this increasingly common scenario.

Augmented Fixation for Fractures of the Appendicular Skeleton

Despite advances in technology such as locked plating, osteoporotic bone and bone defects remain challenging complications for orthopaedic surgeons. The concept of augmented fixation is useful in these settings. Augmented fixation can be described as improving construct strength and stability by enhancing the surrounding environment. By understanding and using the techniques of alternative fixation strategies, endosteal or medullary support, structural grafting, or the use of bone graft substitutes in combination with standard or integrated fixation, surgeons can improve the chances of success when treating difficult fractures. The purpose of this article is to introduce the reader to the concept of augmented fixation, review strategies for its application, and review applicable published results.

Posttraumatic Avascular Necrosis After Proximal Femur, Proximal Humerus, Talar Neck, and Scaphoid Fractures

Posttraumatic avascular necrosis (AVN) is osteonecrosis from vascular disruption, commonly encountered after fractures of the femoral neck, proximal humerus, talar neck, and scaphoid. These locations have a tenuous vascular supply; the diagnosis, risk factors, natural history, and treatment are reviewed. Fracture nonunion only correlates with AVN in the scaphoid. In the femoral head, the risk is increased for displaced fractures, but the time to surgery and open versus closed treatment do not seem to influence the risk. Patients with collapse are frequently symptomatic, and total hip arthroplasty is the most reliable treatment. In the humeral head, certain fracture patterns correlate with avascularity at the time of injury, but most do not go on to develop AVN due to head revascularization. Additionally, newer surgical approaches and improved construct stability appear to lessen the risk of AVN. The likelihood of AVN of the talar body rises with increased severity of talar injury. The development of AVN corresponds with a worse prognosis and increases the likelihood of secondary procedures. In proximal pole scaphoid fractures, delays in diagnosis and treatment elevate the risk of AVN, which is often seen in cases of nonunion. The need for vascularized versus nonvascularized bone grafting when repairing scaphoid nonunions with AVN remains unclear.

Femoral Head Vascularity: Implications Following Trauma and Surgery About the Hip

Traumatic injury and surgical intervention about the hip joint place the arterial supply to the femoral head (FH) at risk. Compromised perfusion may lead to FH ischemia, cell death, and osteonecrosis. Progression to FH collapse may lead to pain, functional impairment, and decreased quality of life, especially in younger patients. This review describes the arterial supply to the FH, analyzes the impact of femoral neck fractures on FH vascularity, and explores the vascular implications of various surgical interventions about the hip, offering specific techniques to minimize iatrogenic damage to the vessels supplying the FH. [Orthopedics. 2019; 42(5):250-257.].

Novel Treatment Options for the Surgical Management of Young Femoral Neck Fractures

In physiologically young patients with displaced femoral neck fractures, surgical treatment is aimed at achieving fracture union while preserving native hip anatomy and biomechanics. The intracapsular environment, tenuous vascular supply, and unfavorable hip biomechanics contribute to the high complication rates seen after osteosynthesis of these fractures. Conventional fixation methods for osteosynthesis of femoral neck fractures include multiple cancellous screws, fixed-angle dynamic implants, and fixed-angle length-stable constructs. Despite several biomechanical and clinical studies evaluating various surgical options, the optimal fixation construct to allow healing and prevent nonunion of displaced femoral neck fractures is not known. This article will review the clinical data regarding conventional fixation constructs and describe the technique and rationale behind 2 novel alternative treatment options for these challenging fractures. The surgical technique and clinical examples for constructs involving multiple cannulated screws/Pauwels screw augmented with a fibular strut graft, as well as a novel fixed-angle locking plate with controlled dynamic compression, are presented.

The Use of Fibular Allograft in Complex Periarticular Fractures Around the Knee

Although the use of fibular strut allografts in proximal humerus fractures has gained popularity, their use in other types of fractures is less well described. Fibular allografts have recently been used in the repair of complex periarticular fractures of the proximal tibia and distal femur. Fibular allografts can be inserted in a variety of manners to achieve goals specific to each individual fracture pattern. In the proximal tibia, insertion through a fracture line or cortical window facilitates joint surface elevation, prevents subsidence and enhances overall construct stability. In distal femoral fractures, including complex periarticular fractures, insertion through the fracture or cortical window permits indirect reduction of the medial cortex and provides necessary medial column support. An additional option in distal femur fractures includes fibula insertion as an intramedullary nail, allowing enhanced fixation in short distal fracture segments. In all cases, the use of a fibular allograft augments poor bone stock and provides improved screw purchase and construct stability when combined with conventional plating methods. Here we present a series of cases at our institution illustrating an array of novel techniques utilizing endosteal fibular allografts in the fixation of complex periarticular fractures about the knee.

Use of fully threaded cannulated screws decreases femoral neck shortening after fixation of femoral neck fractures

BACKGROUND

Femoral neck fractures (FNF) are becoming increasingly common as population ages. Nondisplaced fractures are commonly treated by cancellous, parallel placed, partially threaded cannulated screws (PTS). This allows controlled fracture impaction. However, sliding implants can lead to femoral neck shortening (FNS) that has been shown to be correlated with reduced quality of life and impaired gait pattern. Recently, in our institution we have changed the fixation of FNF to fully threaded screws (FTS) with or without an additional partially threaded screw in order to minimize this phenomenon. The aim of this study was to compare the FNS in patients treated with FTS as compared with our historical controls treated with PTS.

PATIENTS AND METHODS

Between 2014 and 2016, 38 patients with FNF were treated with FTS. Out of the 38, 24 were available for radiographic follow-up. 41 patients treated previously with PTS were available as a control group. Radiographic analysis was performed to assess the FNF in three vectors: Horizontal (X), Vertical (Y) and overall (Z) according to the neck-shaft angle.

RESULTS

Time for admission to surgery was longer in the PTS group (p = 0.04). Patient demographics and major complication rates were similar in the two patient groups. Average FNS in the X axis was significantly smaller in the FTS group than in the PTS group (2.8 ± 3.6 vs 7.6 ± 4.2 mm, p < 0.01) as well as the Y axis (1.2 ± 2.6 vs 4.9 ± 4.2 mm, p < 0.01) and thus also decreased overall Z shortening (2.3 ± 3.5 vs 6.23 ± 4.5 mm, p < 0.01). There was a tendency towards a more valgus reduction in the PTS (137° vs 134°, p = 0.08). There was a significantly smaller number of FTS patients with moderate (5-10 mm) or severe (> 10 mm) FNS. Screw pull-out > 5 mm occurred in 17/41 patients in the PTS but none in the FTS group (p < 0.01).

CONCLUSION

This study proves that use of FTS improves the radiographic results following FNF fixation using cannulated screws.

Diminished abductor muscular strength in patients with valgus-impacted femoral neck fractures treated by internal fixation: Clinical study and biomechanical considerations

BACKGROUND

Valgus-impacted femoral neck fractures treated with internal fixation occasionally result in unsatisfactory postoperative locomotive function, partially due to muscle shortening and a decrease in the moment arm. This study quantifies the degree of diminished abduction strength both clinically and biomechanically.

METHODS

Fifteen patients were enrolled in this study. Twelve patients with fracture healed in valgus-impacted position were further evaluated. Muscular strength around hip was examined, and values between the nonoperated and operated side were compared and analyzed. For the biomechanical study, two three-dimensional models were prepared: model I (control model without displacement) and model II (simulated malunion of a 15° valgus-impacted fracture). Two sets of hip flexion angles in each of the models were simulated with flexion angles of 0° and 23°.

RESULTS

Mean and standard deviation values for muscle strength from the nonoperative/operative side among the valgus group are as follows: flexion strength was 9.2 ± 4.0/9.2 ± 3.2, extension strength was 5.8 ± 2.8/6.1 ± 3.2, abduction strength at 0° was 9.1 ± 3.7/7.4 ± 3.6, abduction strength at 10° was 6.7 ± 3.0/5.5 ± 2.2, and knee extension strength was 15.3 ± 6.2/15.1 ± 6.0 (kgf). When comparing values between the nonoperative and operative sides, statistical significance was only observed in abduction strength ( p < 0.01). The biomechanical models prove that valgus impaction decreases the moment arm by approximately 10% at both flexion angle.

CONCLUSIONS

A significant decrease in abductor strength at 0° and 10° was observed in the valgus-healed group. This may be related to a decrease in the moment arm. Further research should be done to define the acceptable limit of deformity for the satisfactory postoperative functioning.

Endosteal Substitution With an Intramedullary Rod in Fractures of the Femur

BACKGROUND

Morbid obesity and segmental fracture/bone loss are challenging problems in the treatment of fractures and nonunions of the distal femur. The use of an intramedullary rod as an endosteal substitute for a deficient medial cortex along with a lateral locked plate is 1-tool to combat these problems. This article describes the technique used and its results at a single Level 1 trauma center.

METHODS

Retrospective chart and radiographic review of all patients treated for acute fractures and nonunions of the distal femur using endosteal substitution with an intramedullary nail and a lateral locked plate. Fixation construct was determined at the surgeon's discretion and was strongly influenced by bone loss and patient body habitus.

RESULTS

Seven of 8 acute fractures and 8 of 8 nonunions healed without an unplanned reoperation. There were no cases of secondary displacement after fixation, and only 1 unplanned reoperation in the study group.

CONCLUSION

Endosteal substitution with an intramedullary rod and the use of a lateral locked plate provides the stability needed to allow bone healing under prolonged or supraphysiologic loads seen in morbid obesity or segmental bone loss.

LEVEL OF EVIDENCE

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

Focal osteonecrosis in the femoral head following stable anatomic fixation of displaced femoral neck fractures

INTRODUCTION

Femoral head (FH) osteonecrosis (ON) and subsequent segmental collapse is a major concern following displaced femoral neck fractures (FNF). We aimed to quantify residual perfusion to the FH following FNF and evaluate the viability of the FH overtime after surgical fixation.

MATERIALS AND METHODS

Twenty-three patients with FNF underwent dynamic contrast-enhanced (DCE)-MRI to estimate bone perfusion in the FH, using the contralateral side as control. Following open anatomic reduction and a length/angle-stable fixation, a special MRI sequence evaluated the FH for ON changes over time at 3 and 12 months after surgery.

RESULTS

We found significant compromise of both arterial inflow [83.1%-initial area under the curve (IAUC) and 73.8%-peak) and venous outflow (243.2%-elimination rate (K _el)] in the FH of the fractured side. The supero-medial quadrant suffered the greatest decrease in arterial inflow with a significant decrease of 71.6% (IAUC) and 68.5% (peak). Post-operative MRI revealed a high rate (87%-20/23) of small ON segments within the FH, and all developed in the anterior aspect of the supero-medial quadrants. Fracture characteristics, including subcapital FNF, varus deformity, posterior roll-off ≥20° and Pauwel's angle of 30°-50° demonstrated a greater decrease in perfusion compared to contralateral controls.

CONCLUSION

FNF significantly impaired the vascular supply to the FH, resulting in high incidence of small ON segments in the supero-medial quadrant of the FH. However, maintained perfusion, probably through the inferior retinacular system, coupled with urgent open anatomic reduction and stable fixation resulted in excellent clinical and radiographic outcomes despite a high rate of small ON segments noted on MRI.

LEVEL OF EVIDENCE

Level I: Prognostic Investigation.

Dynamic hip screw and fibular strut graft for fixation of fresh femoral neck fracture with posterior comminution

INTRODUCTION

Posterior comminution of the femoral neck fracture is a major cause of delayed and non-union owing to the loss of the buttressing effect against the posterior rotation. When a femoral neck fracture with posterior comminution is anatomically reduced, only the anterior portions of the femoral neck fracture surfaces are brought into contact leaving a posterior defect. The purpose of this study was to evaluate the use of fibular strut grafting and dynamic hip screw (DHS) for fresh femoral neck fractures with posterior comminution in young patient less than 50 years.

MATERIALS AND METHODS

Between October 2012 and March 2016, 35 patients aged 20-50 years, 30 men and 5 women underwent fixation using DHS and fibular strut grafts for Garden grades III (25 patients) and IV (10 patients) femoral neck fractures with posterior comminution. All fractures were reduced by closed methods, and no hip was aspirated. Clinical and radiological outcomes were evaluated.

RESULTS

All patients were in the age group of 20-50 years (mean 37 years). The mean delay in presentation after injury was 1 day. The mean final follow-up for these 35 patients was 27.2 months. Healing of the femoral neck was attained in 34 cases, with an average time to union of 4.8 months (range 4-8 months). One patient underwent arthroplasty due to failure of fixation. According to the Harris hip score, outcome was good to excellent in 30 patients, fair in 4, and poor in 1.

CONCLUSIONS

In our study, only one patient developed non-union and no patients had avascular necrosis of the femoral head. Closed reduction, fibular strut grafts, and DHS fixation is a reliable procedure for femoral neck fractures with posterior comminution in young adults.