RESEARCH ARTICLE
Hippokratia 2024, 28(1): 29-34
Kenanidis E, Frechat SG, Margariti FP, Papavasiliou K, Sarris I, Tsiridis E
Academic Orthopedic Department, Aristotle University Medical School, General Hospital Papageorgiou, Thessaloniki, Greece
Abstract
Background: The long-term studies for femoral neck fractures (FNFs) in young patients treated with closed reduction and internal fixation (CRIF) are limited. This study aimed to evaluate the long-term outcomes of a group of young patients (<65 years) with FNFs treated with CRIF at our department during the last decade. We estimated treatment failure rates and identified risk factors for poor outcomes.
Methods: This retrospective cohort study included patients under 65 with a unilateral FNF treated with CRIF using partially threaded cannulated screws (CSs) between 2011 and 2021. During the latest follow-up visit, we recorded the patients’ complications, re-admissions, reoperations, functional outcomes, and quality of life scores.
Results: We included 52 patients with a mean age of 53.04 years and a mean follow-up of 5.3 (range: 1.3-11) years. No non-union was recorded. Nine patients (17.3 %) underwent total hip arthroplasty (THA) due to femoral head avascular necrosis (AVN) at an average of 1.68 years following the index operation (THA group). The mean age (p =0.96), trauma type (p =0.290), sex prevalence (p =0.989), Garden classification (p =0.187), CSs number (p =0.751), and comorbidities (p =0.516) were comparable between THA and non-THA groups. Time from trauma to index surgery was significantly shorter for the THA than the non-THA group (p =0.03).
Conclusions: During a mid-to-long follow-up, 17.3 % of patients under 65 years who were treated with CRIF and CSs for FNFs developed AVN. Age, trauma type, comorbidities, time from trauma to treatment, and the number of screws did not affect the outcomes. HIPPOKRATIA 2024, 28 (1):29-34.
Keywords: Femoral neck fractures, subcapital hip fractures, long-term follow-up, closed reduction, internal fixation, cannulated screws
Corresponding author: Eustathios Kenanidis MD, MSc, PhD, Assistant Professor of Orthopedic Surgery, 25 Pontou, 55236 Panorama, Thessaloniki, Greece, tel.: +306973693693, e-mail: ekenanidis@auth.gr
Introduction
Femoral neck fractures (FNFs) are hip fractures that occur in two distinct age groups: young adults due to high-energy trauma and elderly individuals due to osteoporosis1. Surgical treatment is preferred for FNFs as it allows quick mobilization, reduces complications, and produces better outcomes2. However, the indications and types of surgical treatment for FNFs in young patients may vary considerably among orthopaedic surgeons. FNFs in young patients are typically treated with reduction under traction and internal fixation (IF) using cannulated screws (CSs) or a dynamic hip screw (DHS)2. It is supported that surgery needs to be performed urgently to preserve the blood flow to the femoral head3.
The number of long-term studies investigating outcomes of patients under 65 with FNFs treated with IF is limited. These studies have reported a complication rate of 14.8-24 %4-6. The fracture type and the reduction quality were identified as the main risk factors for developing complications in this group of patients7. A meta-analysis found no significant difference in complication rates between open reduction and IF using CS or DHS for FNFs, except for a higher rate of avascular necrosis (AVN) in the CS group8. Most surgeons prefer using multiple CSs for undisplaced FNFs, while displaced FNFs equally prefer CSs or DHS9. Surgeons have yet to agree on the appropriate treatment for FNFs in young people. Therefore, it is necessary to conduct further studies to determine the most effective treatment approach.
This study reports on the mid to long-term outcomes of treating young patients (<65 years) with FNFs using closed reduction and IF (CRIF) with CSs over the last decade. Our primary aim was to estimate treatment failure rates, reoperation, and conversion from osteosynthesis to total hip arthroplasty (THA). The secondary aim was to determine the risk factors contributing to unfavorable long-term results.
Materials and Methods
This retrospective cohort study was conducted at the tertiary Academic Orthopedic department of Papageorgiou General Hospital, according to the World Medical Association Declaration of Helsinki, and was approved by the Institutional Research Board (decision No 629, date: 24/08/22). All eligible patients provided written informed consent before enrolling, and all required data was gathered from the hospital’s electronic patient database.
Study population
We identified all unilateral FNFs in patients under 65 years old treated with CRIF using partially threaded CSs between 2011 and 2021. The patients were enrolled in this study if they: i) suffered from a unilateral FNF, ii) were younger than 65 years old at the time of their injury, iii) were admitted to the hospital between 2011 and 2021, and iv) were treated with CRIF using partially threaded CSs. Exclusion criteria were: i) age >65 or <18 years, ii) less than six months follow-up, iii) insufficient follow-up data, iv) conservative or other surgical treatment methods, and v) open fractures.
Operative technique
Patients were positioned supine on a radiolucent fracture table. A C-arm was used intra-operatively. Reduction manoeuvers and traction were not used for non-displaced fractures. In patients with displaced fractures, the reduction was performed in two stages. First, gentle leg traction was applied to restore the limb length. Over-reduction or sudden forceful hip movements were avoided to avoid further damage to the FN capsular vessels. The leg was rotated internally until the fracture was reduced on the axial view. The acceptable reduction was defined as having a neck-shaft angle between 130-150° or slightly valgus, with 15° of anteversion present. Retroversion and varus deformity were not accepted.
The procedures were performed using a mini-lateral hip approach by orthopedic consultants with varying experience levels. Two to four 7.0 mm or 7.3 mm partially threaded CSs were used for fracture fixation after satisfactory reduction in all cases. The aiming device was used to place CSs in a parallel, inverted triangle configuration, spreading into different femoral head segments. Unstable osteoporotic fractures were treated with more screws and washers to prevent screw penetration through the lateral cortex.
Perioperative management
All operations were performed under spinal anesthesia. Intravenous cephalosporin and aminoglycoside were administered immediately preoperatively and for 48 hours postoperatively. Patients received low molecular weight heparin for 30 days postoperatively. Patients were mobilized on the first postoperative day, ambulated with no weight bearing for six weeks, and then partial weight bearing as tolerated until the end of the third postoperative month.
Clinical and radiological assessment
Two resident orthopedic surgeons extracted data for eligible patients from the hospital’s database. Demographics, comorbidities, injury, fracture and implant type, operative data, intra- and postoperative complications, and preoperative and follow-up radiographs were collected. Recently, the patients were re-evaluated at the outpatient clinic. Complications, re-admissions, and reoperations were documented. The hip disability and osteoarthritis outcome score (HOOS)10 and the visual analog scores (VAS) were used to assess postoperative functional outcomes and quality of life. A physical examination was also performed to evaluate the hip range of motion and any painful movements. Standard anteroposterior hip and pelvis and lateral hip radiographs were performed upon the last follow-up visit. Two independent physicians not involved in the index operation evaluated the radiographs.
Statistical analysis
We used standard methods for descriptive statistics. We evaluated the data distribution normality using the Shapiro-Wilk and the Kolmogorov-Smirnov tests. Statistical tests were 2-tailed, and we set the alpha level at 0.05. We assessed continuous variables using the 2-sided independent sample t-test when normally distributed and the Mann-Whitney U-test if not normally distributed. We used the Chi-square test to compare categorical data. We performed statistical analyses using the IBM SPSS Statistics for Windows, Version 27.0 software (IBM Corp., Armonk, NY, USA).
Results
Sixty-seven patients met the inclusion criteria and were initially included in the study. Fifteen patients were lost to follow-up for social reasons unrelated to the study and were excluded. The mean follow-up was 5.3 years, ranging from 1.3 to 11 years. There were 29 female and 23 male patients. Most patients (67.3 %) were injured due to falling from a height. Twenty-three percent of the patients sustained fractures due to high-energy trauma, with 9.6 % being multi-trauma patients. The mean age of patients was 53.04 years, ranging from 19 to 65. Four patients died during the follow-up period due to reasons unrelated to the index surgery. Patients’ demographics and other characteristics are presented in Table 1.
No case of non-union was recorded. Nine patients (17.3 %) were diagnosed with femoral head AVN and required conversion of their fixation to THA (THA group). The mean time from index operation to THA was 1.68 years (6 months-2.9 years). Forty-three patients had not undergone THA since the index operation (non-THA group). The mean age of patients was 52.4 (± 11.1) in the THA group and 53.1 (± 9.1) in the non-THA group.
Both groups’ comparative demographics and other data are shown in Table 2 and Table 3. The mean ages of the THA and non-THA groups were not significantly different (Mann-Whitney test, p =0.96). A comparable number of THAs were performed in patients under 50 and between 50-65 years (χ2 test, p =0.74). There was no difference between THA and non-THA groups concerning the type of trauma (χ2 test =0.290), sex prevalence (χ2 test =0.989), the Garden classification (χ2 test =0.187), the number of CSs used to fix the fracture (χ2 test, p =0.751) and the presence or not of comorbidities (χ2 =0.516) (Table 2 and Table 3). The mean time from trauma to the index surgery for the whole group was 1.29 (0-8) days; for the THA group, it was 0.22 (± 0.66) days, whereas for the non-THA group, it was 1.5 (± 2) days. The time from trauma to the index surgery was significantly shorter for the THA group than for the non-THA group (Mann-Whitney test, p =0.03) (Table 3). The mean HOOS (0.552) and VAS score (0.39) did not differ between the non-THA and the THA groups at the last follow-up (Table 3).
Discussion
Our study demonstrated good mid to long-term outcomes for young patients (<65 years old) with FNFs treated with CRIF with partially threaded CSs. At mid to long-term follow-up, 83 % of patients had good to excellent scores and did not require reoperation. Demographics, trauma type, comorbidities, time elapsed from trauma to fracture fixation, and number of screws used did not affect the outcome of the index operation.
The study’s strength lies in the homogenous group of young patients assessed during a mid to long-term follow-up period. The study involved patients under 65 who underwent CRIF using partially threaded CSs at a single center. To our knowledge, only a limited number of long-term studies in the literature assess treatment outcomes in young patients with FNFs who were treated with CRIF using a single implant4,5. Our study investigated the mid-to-long-term clinical scenario of a young patient with an FNF undergoing CRIF with CSs.
The optimal fixation technique for FNFs in young patients remains to be determined, with open or CRIF being the first-line treatments4. The risk of complications for this patient group has remained relatively high over the past few decades despite various treatments11. The long-term outcomes of CRIF treatment for FNFs in young people are yet to be thoroughly studied. Less than ten retrospective studies have been published, with their sample size ranging from 27-250 patients and the mean follow-up ranging from 2-12.5 years4-6,11-14. CSs are typically used for primary fixation, although some studies have also employed DHS. At a mean follow-up of 5.2 years, our study re-evaluated 52 patients, one of the largest patient cohorts in the literature.
Our study has shown a success rate comparable to other studies reported in the field4-6,11-14. The literature reports non-union and AVN rates between 10 % to 30 % following FNF reduction and IF in young patients4-6,11-14. A meta-analysis of 564 FNFs treated with IF supported an overall non-union incidence of 8.9 % and an AVN incidence of 23 %15. These results are comparable to our findings. The absence of non-union cases in our study might be because all included patients underwent closed reduction and internal fixation without further compromising the femoral head’s blood supply during the operation.
Due to the retrospective design of the studies and the multifactorial nature of complications, it is difficult to identify patients at risk for complications. Poor outcomes after fixation of FNFs have been associated with demographics and other comorbidities4,6,16. There may be an age limit beyond which the risk of complications after surgery increases4. In our study, however, there was no difference in complication risk between individuals under 50 and those aged 50-65. Patient-related risk factors and lifestyle may not increase the risk of complications. However, kidney or respiratory failure, smoking, alcohol abuse, high BMI, and the American Society of Anesthesiologists (ASA) score appear to increase the risk of revision following FNF fixation in all age groups4,6,16. Our study found that the patients’ demographics and comorbidities did not significantly impact the outcomes.
High-energy trauma may cause damage to the capsule and femoral neck vessels, increasing the risk of complications. However, in our study, it was not possible to establish a significant relationship between the type of trauma and the risk of developing complications because only a small number of young patients with FNF sustain their injury following a high-energy trauma6,17. Fracture displacement may be related to the type of trauma, with higher displacement indicating greater force. The fracture displacement may increase vascular damage risk while reducing the possibility of successful fracture reduction. Thus, it is a significant prognostic factor in predicting unfavorable outcomes16,18,19. In this study, the trauma type did not impact the complication risk, and the AVN risk was similar between undisplaced and displaced fractures.
The time elapsed from injury to surgery has been extensively studied as an independent risk factor for poor outcomes in younger patients. Previous studies have shown that the early reduction and IF of FNFs (within 6-24 hours postinjury) can improve the blood supply to the femoral head and reduce the AVN risk20-22. However, several recent studies found no significant difference in the incidence of femoral AVN between early and late fixation for patients with FNFs, regardless of the cut-off value used (12-48 hours)5,6,10-13,23-25. Interestingly, the group that underwent THA had a significantly shorter mean time from injury to index surgery in our study. However, this finding cannot be considered conclusive due to our study’s small number of THA cases. The femoral head blood supply is primarily affected by the momentary detonation force at the time of injury, but it appears to be unrelated to the timing of the surgery.
The preoperative Garden classification and poor fracture reduction quality have been reported as independent risk factors for complications after FNF fixation16,18. Insufficient reduction of a fracture, rotation of the femoral head, and varus deformity can increase shearing forces on the fracture surface, which hinder blood vessel reconstruction around the femoral head5. According to another study, there is no correlation between the AVN rate and the reduction of FNFs11. Our research found that the Garden classification was not different between the THA and non-THA groups. All FNFs were adequately reduced and cannot be further examined in our research.
The implant type used and the amount of weight-bearing after surgery can impact the stability of the fixation and the outcomes. Studies supported the use of DHS in more unstable fracture patterns2. Our study was not designed to examine the effects of different types of implants and the weight-bearing. All patients followed a similar postoperative rehabilitation protocol. Typically, three CSs were used, while four CSs were inserted into the more unstable FNFs. The number of screws used was unrelated to the complication risk in our study.
This retrospective study has several limitations. Due to the extended follow-up period, several patients were lost. Sometimes, the hospital’s database data were insufficient or unavailable. The initial operations were performed by several consultant orthopedic surgeons with different levels of expertise, which may have affected the outcomes. Due to the rarity of FNFs in young adults, only 52 patients were included in the study, making statistical analysis challenging despite the long data collection and analysis. The success of the index surgery also depends on factors not recorded, such as BMI and post-surgery activity levels.
Conclusions
This study demonstrated that 17 % of patients younger than 65 with FNFs treated with CRIF developed AVN at mid to long-term follow-up. The complication rate seen in this study is consistent with the rates previously reported in the literature. The outcome of the index operation was not affected by factors such as the patient’s age, trauma type, comorbidities, the time elapsed from trauma to fracture fixation, or the number of screws used. Therefore, CRIF should be the primary treatment option for these types of fractures.
Conflict of interest
The authors declare no conflicts of interest.
References
- White SM, Griffiths R. Projected incidence of proximal femoral fracture in England: a report from the NHS Hip Fracture Anaesthesia Network (HIPFAN). Injury. 2011; 42: 1230-1233.
- Florschutz AV, Langford JR, Haidukewych GJ, Koval KJ. Femoral neck fractures: current management. J Orthop Trauma. 2015; 29: 121-129.
- Xia Y, Zhang W, Zhang Z, Wang J, Yan L. Treatment of femoral neck fractures: sliding hip screw or cannulated screws? A meta-analysis. J Orthop Surg Res. 2021; 16: 54.
- Kenan S, Gold A, Salai M, Steinberg E, Ankory R, Chechik O. Long-Term Outcomes Following Reduction and Fixation of Displaced Subcapital Hip Fractures in the Young Elderly. Isr Med Assoc J. 2015; 17: 341-345.
- Pei F, Zhao R, Li F, Chen X, Guo K, Zhu L. Osteonecrosis of femoral head in young patients with femoral neck fracture: a retrospective study of 250 patients followed for average of 7.5 years. J Orthop Surg Res. 2020; 15: 238.
- Erivan R, Fassot G, Villatte G, Mulliez A, Descamps S, Boisgard S. Results of femoral neck screw fixation in 112 under 65-years-old at a minimum 2 years’ follow-up. Orthop Traumatol Surg Res. 2020; 106: 1425-1431.
- Shehata MSA, Aboelnas MM, Abdulkarim AN, Abdallah AR, Ahmed H, Holton J, et al. Sliding hip screws versus cancellous screws for femoral neck fractures: a systematic review and meta-analysis. Eur J Orthop Surg Traumatol. 2019; 29: 1383-1393.
- Li L, Zhao X, Yang X, Tang X, Liu M. Dynamic hip screws versus cannulated screws for femoral neck fractures: a systematic review and meta-analysis. J Orthop Surg Res. 2020; 15: 352.
- Slobogean GP, Sprague SA, Scott T, McKee M, Bhandari M. Management of young femoral neck fractures: is there a consensus? Injury. 2015; 46: 435-440.
- Nilsdotter AK, Lohmander LS, Klässbo M, Roos EM. Hip disability and osteoarthritis outcome score (HOOS)–validity and responsiveness in total hip replacement. BMC Musculoskelet Disord. 2003; 4: 10.
- Kang JS, Moon KH, Shin JS, Shin EH, Ahn CH, Choi GH. Clinical Results of Internal Fixation of Subcapital Femoral Neck Fractures. Clin Orthop Surg. 2016; 8: 146-152.
- Razik F, Alexopoulos AS, El-Osta B, Connolly MJ, Brown A, Hassan S, et al. Time to internal fixation of femoral neck fractures in patients under sixty years–does this matter in the development of osteonecrosis of femoral head? Int Orthop. 2012; 36: 2127-2132.
- Duckworth AD, Bennet SJ, Aderinto J, Keating JF. Fixation of intracapsular fractures of the femoral neck in young patients: risk factors for failure. J Bone Joint Surg Br. 2011; 93: 811-816.
- Haidukewych GJ, Rothwell WS, Jacofsky DJ, Torchia ME, Berry DJ. Operative treatment of femoral neck fractures in patients between the ages of fifteen and fifty years. J Bone Joint Surg Am. 2004; 86: 1711-1716.
- Damany DS, Parker MJ, Chojnowski A. Complications after intracapsular hip fractures in young adults. A meta-analysis of 18 published studies involving 564 fractures. Injury. 2005; 36: 131-141.
- Sprague S, Schemitsch EH, Swiontkowski M, Della Rocca GJ, Jeray KJ, Liew S, et al. Factors Associated With Revision Surgery After Internal Fixation of Hip Fractures. J Orthop Trauma. 2018; 32: 223-230.
- Al-Ani AN, Neander G, Samuelsson B, Blomfeldt R, Ekström W, Hedström M. Risk factors for osteoporosis are common in young and middle-aged patients with femoral neck fractures regardless of trauma mechanism. Acta Orthop. 2013; 84: 54-59.
- Wang T, Sun JY, Zha GC, Jiang T, You ZJ, Yuan DJ. Analysis of risk factors for femoral head necrosis after internal fixation in femoral neck fractures. Orthopedics. 2014; 37: e1117-e1123.
- Yang JJ, Lin LC, Chao KH, Chuang SY, Wu CC, Yeh TT, et al. Risk factors for nonunion in patients with intracapsular femoral neck fractures treated with three cannulated screws placed in either a triangle or an inverted triangle configuration. J Bone Joint Surg Am. 2013; 95: 61-69.
- Szita J, Cserháti P, Bosch U, Manninger J, Bodzay T, Fekete K. Intracapsular femoral neck fractures: the importance of early reduction and stable osteosynthesis. Injury. 2002; 33 Suppl 3: C41-C46.
- Jain R, Koo M, Kreder HJ, Schemitsch EH, Davey JR, Mahomed NN. Comparison of early and delayed fixation of subcapital hip fractures in patients sixty years of age or less. J Bone Joint Surg Am. 2002; 84: 1605-1612.
- Kuner EH, Lorz W, Bonnaire F. Schenkelhalsfrakturen beim Erwachsenen: gelenkerhaltende Operationen. I. Ergebnisse der AO-Sammelstudie mit 328 Patienten [Femoral neck fractures in adults: joint sparing operations. I. Results of an AO collective study with 328 patients]. Unfallchirurg. 1995; 98: 251-258.
- Wongwai T, Wajanavisit W, Woratanarat P. Non-union and avascular necrosis of delayed reduction and screw fixation in displaced femoral neck fracture in young adults. J Med Assoc Thai. 2012; 95 Suppl 10: S120-S127.
- Araujo TP, Guimaraes TM, Andrade-Silva FB, Kojima KE, Silva Jdos S. Influence of time to surgery on the incidence of complications in femoral neck fracture treated with cannulated screws. Injury. 2014; 45 Suppl 5: S36-S39.
- Butt MF, Dhar SA, Gani NU, Farooq M, Mir MR, Halwai MA, et al. Delayed fixation of displaced femoral neck fractures in younger adults. Injury. 2008; 39: 238-243.