Hidden osteonecrosis of the femoral head after healed femoral neck fractures: magnetic resonance imaging study of 58 consecutive patients

Clinical applications and cadaveric study of the free descending genicular artery perforator flap without the saphenous vein

BACKGROUND

The descending genicular artery (DGA) and medial thigh region have been underused as donor sites for perforator flaps. This study evaluated the anatomical relationship between the perforators of the DGA and the saphenous vein (SV) to review the clinical applications of the free descending genicular artery perforator (DGAP) flap for locoregional reconstruction.

METHODS

Fifteen cadavers were arterially perfused with red latex and dissected. Thirty-one patients with extremity tissue defects were treated with a free DGAP flap, including six patients who received a chimeric flap. The minimum distance between the DGAP and the SV was measured during surgery.

RESULTS

In all patients, the skin branch of the descending genicular artery was found in the medial femoral condyle plane in front of the SV. The average distance between the descending genicular artery perforator and the SV was 3.71 ± 0.38 cm (range: 2.9-4.3 cm). Thirty flaps survived completely, and one flap developed partial necrosis; however, this flap healed two weeks after skin grafting. The average follow-up time was 11.23 months.

CONCLUSIONS

We conclude that the SV can be preserved when harvesting the descending genicular artery perforator flap, causing less damage to the donor site and having no effect on flap survival. The free descending genicular artery perforator flap without the SV is a better therapy for complicated tissue defects.

Residual deformity after femoral neck fracture affects the location of osteonecrosis of the femoral head

Aims

The localization of necrotic areas has been reported to impact the prognosis and treatment strategy for osteonecrosis of the femoral head (ONFH). Anteroposterior localization of the necrotic area after a femoral neck fracture (FNF) has not been properly investigated. We hypothesize that the change of the weight loading direction on the femoral head due to residual posterior tilt caused by malunited FNF may affect the location of ONFH. We investigate the relationship between the posterior tilt angle (PTA) and anteroposterior localization of osteonecrosis using lateral hip radiographs.

Methods

Patients aged younger than 55 years diagnosed with ONFH after FNF were retrospectively reviewed. Overall, 65 hips (38 males and 27 females; mean age 32.6 years (SD 12.2)) met the inclusion criteria. Patients with stage 1 or 4 ONFH, as per the Association Research Circulation Osseous classification, were excluded. The ratios of anterior and posterior viable areas and necrotic areas of the femoral head to the articular surface were calculated by setting the femoral head centre as the reference point. The PTA was measured using Palm's method. The association between the PTA and viable or necrotic areas of the femoral head was assessed using Spearman's rank correlation analysis (median PTA 6.0° (interquartile range 3 to 11.5)).

Results

We identified a negative correlation between PTA and anterior viable areas (rho -0.477; p = 0.001), and no correlation between PTA and necrotic (rho 0.229; p = 0.067) or posterior viable areas (rho 0.204; p = 0.132).

Conclusion

Our results suggest that residual posterior tilt after FNF could affect the anteroposterior localization of necrosis.

Comparison of young femoral neck fractures treated by femoral neck system, multiple cancellous screws and dynamic hip screws: a retrospectively comparison study

BACKGROUND

Implant choice for the fixation of femoral neck fracture is one of the most important management controversies. This study aims to evaluate and compare the short-term outcomes associated with the use of the Femoral Neck System (FNS), Multiple Cancellous Screws (MCS), and Dynamic Hip Screws (DHS) in treating femoral neck fractures in a young patient population.

METHODS

From June 2018 to June 2021, a total of 120 surgeries for a primary femoral neck fracture were retrospectively analyzed. This review encompassed demographic details of the patients and the mechanisms behind the injuries. Key surgical parameters such as operation duration, intraoperative blood loss, fluoroscopy duration, and hospital stay were meticulously documented. The employed surgical technique was described. All patients were followed up at 6 weeks, 3 months, 6 months, and 12 months postoperatively. Avascular necrosis of the femoral head (AVN), nonunion, malreduction, implant failure or other complications were noted. The functional status at the last follow-up was assessed using the Harris functional scoring criteria.

RESULTS

There were 90 males and 30 females, with a mean age of 40.4 years. As to patient characteristics, there were no significant differences between the three groups. DHS group showed longer operation time(52.15 ± 4.80 min), more blood loss(59.05 ± 5.87 ml) and longer time of hospitalization(7.6 ± 0.90 d) than FNS group (39.65 ± 2.84 min, 45.33 ± 9.63 ml and 4.87 ± 0.48 d) and MCS group (39.45 ± 3.10 min, 48.15 ± 7.88 ml and 5.04 ± 0.49 d) (p < 0.05). In addition, the time of fluoroscopy in FNS group (15.45 ± 3.67) was less than that in MCS group (26.3 ± 4.76) and DHS group (27.1 ± 5.67) (p < 0.05). The cost of FNS group(44.51 ± 2.99 thousand RMB) was significantly higher than the MCS and DHS groups. The FNS, MCS and DHS groups showed a similar mean length of femoral neck shortening (LFNS) and Harris score. The FNS, MCS and DHS groups showed a similar mean rate of AVN and internal fixation failure.

CONCLUSIONS

Following successful fracture reduction, FNS, MCS, and DHS are effective for in the young femoral neck fractures. No difference was found in complications between the three groups. However, the reduced fluoroscopy time associated with FNS contributes to shorter operation durations. The adoption of minimally invasive techniques correlates with decreased blood loss and shorter hospital stays. Nevertheless, these advantages may be offset by the potential economic burden they impose.

Latent infections in conversion total hip arthroplasty following internal fixation of femoral neck fractures: a systematic review and meta-analysis of diagnostic methods

BACKGROUND

Accurate diagnosis of latent infections prior to conversion total hip arthroplasty (THA) following internal fixation of femoral neck fractures is crucial for successful surgical outcomes. This systematic review aimed to provide a comprehensive evaluation of the current literature regarding the diagnosis of latent infections before conversion THA.

METHODS

Systematic search of PubMed, EMBASE, and Cochrane (CENTRAL) databases was conducted, and the diagnostic accuracy of various markers and techniques was assessed. The quality of the included studies was evaluated using the QUADAS-2 instrument.

RESULTS

Five studies comprising 661 patients were included in the review. Pooled analysis using C-reactive protein (CRP) as a diagnostic marker resulted in a sensitivity and specificity of 72% and 76%, respectively, while using erythrocyte sedimentation rate (ESR) yielded a sensitivity and specificity of 75% and 78%, respectively. Fibrinogen and platelet count showed lower sensitivity and specificity compared to CRP and ESR. The best combined markers were CRP and serum platelet count, with a sensitivity of 76% and specificity of 86% based on one study.

CONCLUSION

Our review underscored the limitations and inconsistencies present in current diagnostic methods for latent infections in conversion surgery. Future research needs to focus on standardizing threshold values, exploring the potential of synovial fluid analysis, imaging techniques, and molecular methods, as well as developing tailored diagnostic algorithms.

PROSPERO

CRD42023394757.

Association of hardware removal with secondary osteonecrosis following femoral neck fractures: a systematic review and meta-analysis

BACKGROUND

It has been controversial that whether hardware removal will increase the risk of osteonecrosis of femoral head (ONFH) in fracture-healed patients who underwent internal fixation for femoral neck fractures (FNFs). This meta-analysis aimed to clarify the association of hardware removal with secondary hardware removal-induced ONFH (HR-ONFH).

METHODS

Four electronic databases (PubMed, Embase, Web of Science, Cochrane Library) were searched for eligible studies published up to March 10, 2023. Studies reporting the relative risk of hardware status (i.e., risk rate, odds ratio [OR], or hazard ratio [HR]) were included. Newcastle-Ottawa scale (NOS) was used to assess risk of bias of included observational studies. Review Manager software was used to pool ORs and adjusted ORs.

RESULTS

Five studies were included into quantitative synthesis. Hardware removal was associated with a reduced risk of HR-ONFH in the synthesis of crude odds ratios (OR, 0.62, 95% CI 0.39-0.96). In the synthesis of adjusted odds ratios, hardware removal was associated with an increased risk of HR-ONFH (OR, 1.76, 95% CI 1.23-2.51).

CONCLUSION

This study demonstrates that hardware removal was associated with an increased incidence of HR-ONFH in fracture-healed patients who underwent internal fixation due to FNFs.

The incidence of focal osteonecrosis of the femoral head and its impact on conversion hip arthroplasty after screw fixation of femoral neck fractures: a multicenter retrospective study based on postoperative magnetic resonance imaging

PURPOSE

Osteonecrosis of the femoral head (ONFH) and subsequent head collapse is a major concern after internal fixation of femoral neck fracture (FNF). Previous studies focused on ONFH incidence using plain radiography; postoperative magnetic resonance imaging (MRI) was rarely performed. We performed a multicenter retrospective study to investigate the incidence of ONFH and the need for conversion hip arthroplasty after FNF screw fixation.

METHODS

We reviewed 195 patients who underwent screw fixation during closed FNF reduction between 2012 and 2017 at three institutions. Except for patients who did not consent to MRI, all patients underwent postoperative MRI either 1-3 years after screw fixation. The occurrence of ONFH was investigated through plain radiography and MRI.

RESULTS

Thirty patients were diagnosed with ONFH through plain radiography, and an additional 33 patients were diagnosed with MRI, resulting in a total of 63 patients (32.3%) diagnosed with ONFH. The mean time to ONFH diagnosis was 18.9 months and the conversion rate to hip arthroplasty was 10.2%. Of the 33 patients who were normal on hip radiography but exhibited ONFH on MRI, all had small focal lesions not associated with head collapse at the last follow-up. The ONFH group diagnosed through plain radiography had more unstable FNFs than the group diagnosed through MRI.

CONCLUSION

Although postoperative MRI revealed a higher incidence of ONFH after FNF screw fixation than reported previously, the small focal MRI lesions were not associated with increased risks of femoral head collapse or conversion to arthroplasty.

The Risk of Avascular Necrosis Following the Stabilization of Femoral Neck Fractures: A Systematic Review and Meta-Analysis

Background: Avascular necrosis (AVN) of the femoral head often requires surgical treatment and is often associated with femoral neck fractures. We conducted a systematic review and meta-analysis of recent research on the risk of AVN following the stabilization of fractured femoral neck with implants in PubMed. We assessed the effect of age on AVN incidence among patients aged > 50 and younger, depending on fracture type, Garden stage, Pouwels degree, Delbet stage, and age category. We followed PRISMA guidelines. Relevant studies were defined as research articles describing real-world studies reporting on the risk of AVN following primary surgical fracture stabilization with implants, published between 1 January 2011 and 22 April 2021. Fifty-two papers met the inclusion criteria, with a total of N = 5930 with surgically managed fractures. The pooled mean AVN incidence was significantly higher among patients with displaced fractures (20.7%; 95% CI: 12.8−28.5%) vs. those with undisplaced fractures (4.7%; 95% CI: 3.4−6.0%). No significant correlation was observed between AVN incidence weighted by sample size and time interval from injury to surgery (p = 0.843, R2 = 0.01). In conclusion, the risk of AVN following femoral neck fractures was generally high, especially in patients with displaced fractures. The time from injury to surgery did not correlate with AVN incidence.

Addressing posterior tilt displacement during surgery to lower failure risk of sub-capital Garden types 1 and 2 femoral fractures

INTRODUCTION

Sub-capital femoral fractures (SCFF) are impacted or non-displaced in Garden types 1 and 2, respectively. Non-surgical treatment is protected weight-bearing combined with physiotherapy and radiographic follow-up in selected patients. Traditionally, in situ pinning is the surgical treatment of choice. The aim of this study was to estimate whether the valgus deformity in Garden types 1 and 2 (AO classification 31B1.1 and 31B1.2) SCFF is a virtual perception of a posterior tilt deformity and if addressing this deformity improves patients' outcomes.

MATERIALS AND METHODS

The records of 96 patients with Garden Types 1 and 2 SCFF treated in tertiary medical center between 1/2014 and 9/2017 were retrospectively reviewed. They all had preoperative hip joint anteroposterior and lateral radiographic views. 75 patients had additional computed tomography (CT) scans. Femoral head displacement was measured on an anteroposterior and axial radiograph projections and were performed before and after surgery. Preoperative 3D reconstructions were performed for a better fracture characterization, and assessment of the imaging was performed by the first author.

RESULTS

The average age of the study cohort was 73 years (range 28-96, 68% females). There were 58 right-sided and 38 left-sided fractures. Ninety patients had Type 1 and six patients had Type 2 fractures. The average preoperative posterior tilt was 15 degrees and the average valgus displacement was 10 degrees on plain radiographs compared to 28 degrees and 11 degrees, respectively, on CT scans. Posterior tilt was found with a virtual perception as valgus-impacted fractures. The postoperative posterior tilt was corrected to an average of 3 degrees and the valgus displacement to 5 degrees.

CONCLUSION

CT provides an accurate modality for measuring femoral head displacement and fracture extent. The posterior tilt displacement should be addressed during surgery to lower failure risk and the need for additional procedures.

IRB APPROVAL

TLV-0292-15.

LEVEL OF EVIDENCE

IV.