The effect of fully threaded cannulated screws in sliding fixation of femoral neck fractures: a retrospective study.

To investigate the short- and medium-term effectiveness of percutaneous compression plate (PCCP) internal fixation for femoral neck fractures in the elderly. The clinical data of 32 elderly patients with femoral neck fracture treated with PCCP internal fixation between January 2012 and January 2019 were retrospectively analyzed. All of them were traumatic fractures. The causes of injury were falling in 20 cases, traffic accident in 7 cases, and falling from height in 5 cases. According to Garden classification, there were 7 cases of type Ⅱ, 15 cases of type Ⅲ, and 10 cases of type Ⅳ; there were 12 cases with Singh index level Ⅳ, 14 cases with level Ⅴ, and 6 cases with level Ⅵ; the bone mineral density of femoral neck was 0.610-0.860 g/cm 2 (mean, 0.713 g/cm 2). The time from injury to operation was 3-14 days, with an average of 5.8 days. Patients began to weight-bear gradually within 3 days postoperatively. The operation time, intraoperative blood loss, hospitalization stay, fracture reduction (Garden alignment index), fracture healing, failure of internal fixation, femoral neck shortening, and osteonecrosis of the femoral head were observed; hip function recovery was evaluated by Harris score. The operation time was 35-135 minutes (mean, 73.4 minutes), the intraoperative blood loss was 75-385 mL (mean, 116.4 mL), the hospitalization stay was 3-15 days (mean, 8.3 days). At 1 week after operation, the Garden alignment index of fracture reduction was grade Ⅰ in 25 cases, grade Ⅱ in 6 cases, and grade Ⅲ in 1 case. One case of superficial infection of the incision occurred after operation, and no early complications such as deep vein thrombosis in the lower extremities, pulmonary embolism, or bedsores occurred. All the patients were followed up 2.1-4.0 years, with an average of 2.7 years. Except for 2 cases of delayed union (displaced trans-neck and subhead fractures), no nonunion of fracture and failure of internal fixation occurred, the fracture healing time was 4-8 months, with an average of 4.9 months. Femoral neck shortening occurred in 12 cases (37.5%); osteonecrosis of the femoral head occurred in 3 cases (9.4%), all of which were displaced trans-neck and subhead fractures, of which 2 cases received total hip arthroplasty and the other received conservative treatment. The Harris scores of the hip joint at 3 months, 2 years after operation and at last follow-up were significantly improved when compared with those before operation ( P<0.05); there was no significant difference between each time point after operation ( P>0.05). At last follow-up, the hip joint function was evaluated according to Harris score, the results were excellent in 15 cases, good in 12 cases, and fair in 5 cases, with an excellent and good rate of 84.4%. There was no significant difference in postoperative hip function composition among patients with different ages, Garden classification, Singh index, and Garden alignment index ( P>0.05). For elderly patients with femoral neck fractures without severe osteoporosis and with relatively good physical conditions, PCCP internal fixation can achieve satisfactory short- and medium-term effectiveness, but there is a certain risk of osteonecrosis of the femoral head.

The aim of this study was to assess the factors affecting femoral neck shortening after internal fixation of femoral neck fractures. Eighty-six patients with femoral neck fractures were treated using three parallel cannulated screws between May 2004 and January 2011. The shortening of the femoral neck in the horizontal (X), vertical (Y), and along the resultant along the (Z) vector (X➝, Y➝, Z➝) was measured on anteroposterior radiographs corrected by screw diameter and analyzed using TraumaCad software. Age, gender, Garden classification, Garden's alignment index, Pauwels angle, Singh index, body mass index and weight-bearing time were also analyzed. Follow-up duration was 8 to 36 months. Significant femoral neck shortening of the abductor lever arm (greater than 5 mm) was present in 33 of 86 (38.4%) patients. Average Harris score (HSS) was 90.05 ± 7.04 (range: 71 to 100). The 5 predictors for shortening greater than 5 mm in the multivariate logistic regression model were age, Singh index, Pauwels classification, Garden's alignment index and body mass index. Femoral neck shortening associated with three parallel cannulated screws for fixation of femoral neck fractures is a common phenomenon. Femoral neck shortening after internal fixation is affected by multiple cofactors.

To compare the effectiveness of full thread compression cannulated screw and partial thread cannulated screw in the treatment of femoral neck fracture. A retrospective analysis was made on 152 patients with femoral neck fractures, who met the selection criteria, between April 2013 and February 2021. The fractures were fixed with the full thread compression cannulated screws in 74 cases (trial group) and the partial thread cannulated screws in 78 cases (control group). There was no significant difference in general data such as age, gender, body mass index, cause of injury, time from injury to operation, and the side, Garden typing, Pauwels typing of fracture between the two groups (P>0.05). The operation time, intraoperative blood loss, hospital stay, follow-up time, and Harris score were recorded in both groups. X-ray films were performed to evaluate the quality of fracture reduction and bone healing, the changes of neck-shaft angle, the changes of femoral neck, as well as the occurrence of internal fixation failure, screw back-out, and osteonecrosis of the femoral head. There was no significant difference in operation time and hospital stay between the two groups (P>0.05). However, the intraoperative blood loss in the trial group was significantly lower than that in the control group (P<0.05). Patients in both groups were followed up, with the follow-up time of (24.11±4.04) months in the trial group and (24.10±4.42) months in the control group, and the difference was not significant (P>0.05). Postoperative X-ray films showed that there was no significant difference in fracture reduction grading between the two groups (P>0.05). Six cases in the trial group developed bone nonunion and 7 cases in the control group, the fractures of the other patients healed, and the healing time was significantly shorter in the trial group than in the control group (P<0.05). There was no significant difference in the incidence of bone nonunion between the two groups (P>0.05). During follow-up, 2 cases in the trial group and 5 cases in the control group had osteonecrosis of the femoral head, the difference was not significant (P>0.05), and the patients with osteonecrosis of the femoral head were treated with secondary operation. The screw back-out occurred in 3 cases of the trial group and in 9 cases of the control group, showing no significant difference (P>0.05). But the screw back-out distance was significantly shorter in the trial group than in the control group (P<0.05). The incidence of internal fixation failure in the trial group (4 cases) was significantly lower than that in the control group (14 cases) (P<0.05). The incidence of femoral neck shortening and the change of neck-shaft angle at 1 year after operation were significantly lower in the trial group than in the control group (P<0.05). The Harris score at last follow-up was significantly higher in the trial group than in the control group (P<0.05). Compared with the partial threaded cannulated screws, the full threaded cannulated compression screws can effectively maintain fracture reduction, avoid femoral neck shortening, and internal fixation failure. It is a better choice for femoral neck fracture.

Objective Using finite element analysis to study how the biomechanics of femoral head and neck changes after neck shortening, and discuss the mechanism of obvious higher osteonecrosis of the femoral head (ONFH) rate in femoral neck shortening cases. Methods MIMICS was used to build three femoral neck fracture models with Pauwells angle of 70 degrees. The neck lengths of the three models respectively were normal, 2.5 mm shortened and 5.0 mm shortened. Every model was assembled with 3 hollow screws, and imported into the finite element analysis software ABAQUS. The stress change of femoral head and neck was analyzed by loading and restraint. Results When the femoral neck length was normal, 2.5 mm shortened and 5.0 mm shortened, the maximal tensile stress of hollow screws in upper part of the femoral neck was 15.7, 14.1 and 12.4 mPa, and the compressive stress of lower part of femoral neck was 20.2, 19.1 and 17.8 mPa, respectively. Meanwhile, the high stress bearing district was transfered to right above the femoral head from its superior lateral quadrant, and the maximum stress of non-main stress bearing district was 10.6, 12.8 and 17.2 mPa respectively. Conclusion The femoral neck shortening reduces the proximal femoral eccentricity. It doesn’t affect the stabilities of internal fixation and fracture ends, but it transfers the stress bearing district of femoral head and causes the forming of high stress bearing district in non-main stress bearing district. Key words: Femoral neck fracture; Femoral neck shortening; Biomechanics

Osteonecrosis of the femoral head (ONFH), also called avascular necrosis of the femoral head (AVN), is a common and often refractory disease in the orthopaedic domain. ONFH can be caused by trauma or other factors (nontraumatic). Traumatic ONFH is caused mainly by trauma to the hip, such as femoral neck fracture or hip dislocation. In China, the causes of nontraumatic ONFH are mainly corticosteroid treatment and/or alcohol abuse. ONFH is progressive and about 80% of necrotic femoral heads will collapse within 1 to 4 years in the absence of effective treatment. Collapse of the femoral head (manifested as subchondral fracture and a positive crescent sign) can progress to severe osteoarthritis requiring prosthetic replacement. Nontraumatic ONFH mainly affects young and middle-aged people and bilateral hip involvement is common (approximately 80%). Because the long-term efficacy of total hip arthroplasty in young and middle-aged patients is unpredictable, it is important to perform joint-preserving procedures in the early stages. Based on the suggestions of the Association Research Circulation Osseous (ARCO) and American Academy of Orthopaedic Surgeons, ONFH can be defined as a disease involving the femoral head and characterized by structural change, collapse and joint dysfunction resulting from necrosis caused by interruption or impairment of the blood supply to the femoral head, and subsequent repair of the bone cells and marrow. Based on the diagnostic criteria of the Japanese Investigation Committee and Mont, we propose that the following diagnostic criteria for ONFH are appropriate for China. Clinical symptoms, signs and history which include hip joint pain involving the inguinal region, buttocks and upper leg; limited and painful internal rotation of the hip joint; a history of hip trauma, corticosteroid application and/or alcohol abuse. Radiographic findings: (i) femoral head collapse without joint space narrowing; (ii) calcification band(s) with clear borders inside the femoral head; and (iii) lucent band(s) in subchondral bone (subchondral fracture or positive crescent sign). Radionuclide bone scanning shows a cold area within the hot area of the femoral head. Magnetic resonance imaging of the femoral head shows a banded low signal shadow (banded type) in T1 weighted images or a double-line sign in T2 weighted images. Bone biopsy shows empty osteocytic lacuna with multiple trabecular involvement in >50% of trabeculae as well as necrotic bone marrow. Radiographic findings: (i) femoral head collapse with narrowed joint space; (ii) cystic changes or spotted calcification inside the femoral head; and (iii) flattening of the lateral superior aspect of the femoral head. Radionuclide bone scanning shows a cold or hot area inside the femoral head. Magnetic resonance imaging of the femoral head shows homogenous or heterogeneous low intensity signals with banded changes in T1 weighted images. Two or more positive primary criteria are sufficient for a diagnosis of ONFH. One positive primary criterion with three positive secondary criteria, including at least one positive radiographic sign, are sufficient for a diagnosis of possible ONFH. Clinical examination: a detailed case history, including any hip trauma, consumption of corticosteroids, alcohol abuse and/or anemia, should be taken and clinical features, such as the site and characteristics of any pain and the relationship between pain and weight bearing, should be collected. The physical examination should include assessment of the rotation of the involved hip joint. Radiography: ONFH in its early phases (phases 0 and I) is difficult to identify by radiography. Positive radiographic findings for phase II or greater phases of ONFH include calcification bands, radiotransparent cystic changes, spotty calcification, subchondral fracture and femoral head collapse. The recommended views on radiography include the anteroposterior and frog lateral views, the latter allowing clearer visualization of a necrotic femoral head. Magnetic resonance scan: MR scan is the most reliable method for the diagnosis of early ONFH with a sensitivity and specificity of up to 96%–99%. Typical MRI findings in ONFH include a spirally banded low signal and/or low signal surrounding a region of high or heterogeneous signal at the proximal end of, or across, the residual bone marrow line of the involved femoral head in T1 weighted images. T2 weighted images show a typical double-line sign. Combined T1 and T2 weighted imaging is recommended, supplemented with fat-suppression or short T1 inversion recovery sequencing for a suspected lesion. Sagittal scanning should be used to supplement the routine employment of coronal or transverse scanning, because it allows more precise estimation of the volume of necrosis and visualization of the lesion. Gadolinium-enhanced MRI is superior for the diagnosis of early ONFH. Radionuclide bone scanning: radionuclide bone scanning has high sensitivity and low specificity for diagnosing early ONFH. A cold area within a hot area in a scan for which 99mTC was used is a characteristic manifestation of ONFH, but the presence of pure radionuclide aggregation (hot area) should be differentiated from other joint diseases. This method of examination can be used for screening for the disease at an early phase or for involvement of multiple sites. Single photon emission computer tomography increases the sensitivity rather than the specificity. Computed tomography scanning: CT scanning can clearly display the borders, area, calcified bands, autologous repair and subchondral fractures of ONFH in phases II and III, but is useless for ONFH in phase I. CT scanning surpasses MRI and radiography in displaying any subchondral fracture. A supplemented two-dimensional reconstruction can display the overall femoral head from a coronal view. CT scanning is a useful method for determining the severity of the lesion and the appropriate therapeutic regimen. Other investigations: positron emission tomography, 67Ga or sulfur colloid labeled radioisotope scanning and T2 dynamic MRI blood flow perfusion determination for the diagnosis of early ONFH are currently being testing prior to their clinical application. Moderate/severe osteoarthritis. Typical osteoarthritis is not difficult to differentiate from ONFH, but a slightly narrow joint space and subchondral cystic changes may lead to a misdiagnosis. This disease typically shows calcification and cystic change on CT scanning, low signals on MRI and bony outgrowths at the medial lower margin of the femoral head. Osteoarthritis secondary to acetabular dysplasia. This is not difficult to differentiate from ONFH because it has characteristic radiographic findings including shallow acetabulum, narrowed or absent joint space in the superior lateral region of the femoral head, bony calcification, cystic changes and changes in the corresponding acetabular region similar to the weight-bearing region of the femoral head. Ankylosing spondylitis-related hip arthritis. This is not difficult to identify because of the following typical clinical properties: common in young male patients, bilateral sacroiliac joint involvement, HLA-B27 (+) and a narrowed or absent joint space (or even joint fusion), with a femoral head that is still round. However, patients with a history of long-term corticosteroid administration may develop concomitant ONFH, presenting with a mild to moderate femoral head collapse. Rheumatoid arthritis. This is not difficult to identify on the basis of the following characteristics: a common disease in female patients, narrowed or absent joint space with a round femoral head, frequent subchondral erosion of the femoral head, cystic changes and acetabular erosion. Idiopathic transient osteoporosis of the hip (ITOH). This is caused by transient painful bone marrow edemaand is common in middle-aged people. Its radiographic findings are bone mass reduction at the femoral head, neck and even the trochanter. MRI shows homogenous low signals on T1 weighted images and high signals on T2 weighted images, ranging from the neck to the trochanter of the femoral head, without the banded low signal changes that are seen in ONFH. ITOH can spontaneously resolve 3–6 months after onset. Subchondral incomplete fracture. Clinical features include: common in patients aged more than 60 years, absence of a trauma history, sudden onset of hip pain, walking difficulties and restricted joint movement. Radiography shows slight flattening of the superior lateral aspect of the femoral head. MRI shows subchondral low signals and edema of the surrounding bone marrow on T1 and T2 weighted images, and flaky high signals on T2 fat-suppression images. This fracture is a fracture of tiny trabeculae secondary to osteoporosis. Pigmented villonodular synovitis. This involves the knee joints more often than the hip joints. The features of hip pigmented villonodular synovitis include common in young people, mild to moderate hip pain with claudication and mild restriction of joint movement in the early and middle stages and severe restriction of joint movement in the advanced stage. CT scanning and radiography show cortical erosion at the femoral head, neck and/or acetabulum and mild to moderate narrowing of the joint space. MRI shows extensive synovial hypertrophy involving the overall joint with well distributed low to moderate intensity signals. Femoral head bruise. This is characterized by a hip trauma history, hip pain and claudication. MRI shows moderate intensity signals inside the femoral head on T1 weighted images and high intensity signals on T2 weighted images, more often on the medial side of the femoral head. Synovial herniation pit. This is a benign disease characterized by invasion of hyperplastic synovial tissue into the cortex of the femoral neck. MRI shows low signals on T1 weighted images and small round lesions with high signals on T2 weighted images. It is commonly manifested as asymptomatic erosion of the the cortex in the superior region of the femoral neck. Once ONFH has been diagnosed, scientific staging should be undertaken. This is very helpful for selecting an appropriate treatment plan, accurately assessing the prognosis, and comparing the effects of treatment. We recommend the following staging methods: ARCO staging (Table 1), Steinberg staging (Table 2) and Ficat staging (Table 3). An appropriate treatment strategy should be selected according to the stage, volume of osteonecrosis, age, joint function and occupation of the patient. Currently, there is no single method for managing all variations of ONFH regardless of type, stage and necrotic volume. The treatment methods for ONFH are both non-surgical and surgical and each has its own indications. Whether weight bearing with protection can prevent collapse of the femoral head is controversial. Weight-bearing with crutches is recommended to reduce the pain, whereas use of a wheelchair is not recommended. This is suitable for the pre-collapse stage of ONFH (ARCO Stages 0, I, II) and includes non-steroidal anti-inflammatory analgesics, low molecular weight heparin, Chinese medicine for treating thrombophilia or hypofibrinolysis, alendronate for preventing collapse of the femoral head, vasodilator drugs and drugs for elimination of bone marrow edema. These include extracorporeal shock wave and high-frequency magnetic field therapy. All these methods are useful for alleviating pain and promoting recovery of necrotic bone. The procedures include joint-preservation and joint-replacement surgery. This utilizes the procedures of core decompression, bone grafting, and osteotomy and is suitable for ONFH in ARCO Stages I, II, and IIIA. If the procedure is selected appropriately, it is possible to avoid or delay joint replacement. Core decompression surgery has a long history and recognized benefits in the treatment of ONFH ARCO Stages I and II. It is recommended that a 3-mm wire be used to produce multiple holes under fluoroscopic control in combination with autologous bone marrow cell transplantation or bone morphogenetic protein. This is not recommended for advanced stages (ARCO Stages III and IV). Common methods used in the clinic include vascularized fibular grafting, vascularized iliac bone grafting, and bone grafting with preservation of muscle blood supply. These are suitable for young or middle-aged ONFH patients (ARCO Stages IIC, IIIA, and IIIB). When these surgical procedures are used appropriately, the mid- and long-term effects are good. However, the more severe surgical trauma, technical difficulty, and a certain percentage of complications at the donor site are disadvantages of these procedures. Currently, bone grafting with core decompression via the greater trochanter of the femur or via a femoral neck window is popular. Methods include support bone grafting and impaction bone grafting. Materials used for the bone graft include autologous bone, artificial substitutes, and allograft bone. These are suitable for young or middle-aged ONFH patients in ARCO Stages IIB and IIC with a necrotic volume >25%. Less surgical trauma, technical difficulty, and a small percentage of complications at the donor site are advantages of these procedures. The mid-term result is acceptable but the long-term results are still difficult to predict. The principle of osteotomy is to alter the weight-bearing surface of the femoral head, that is to say, shift the necrotic region out of the weight-bearing surface and make the non-necrotic region the weight-bearing surface. Methods include intertrochanteric varus/valgus osteotomy and transtrochanteric osteotomy. These are suitable for young or middle-aged ONFH patients with moderate Stage II and earlier stages, and middle stage III. When these surgical procedures are used appropriately the results are acceptable, but this surgery can create some technical difficulties for any future arthroplasty. This is still controversial. Some studies suggest that active treatment should be undertaken for large volume necrosis (>30%) and when the necrotic region is located on the weight-bearing surface of the femoral head, rather than waiting for symptoms to occur. Once collapse of the femoral head has progressed to the advanced stages of III, IV or V or there is joint dysfunction and severe pain, total hip replacement should be recommended. Surface replacement, metal-on-metal surface replacement, or the double-acting type of femoral head replacement should be suggested for young patients (<50 years old). These procedures are transitional surgery which preserves more bone quantity for future arthroplasty revision. The procedures above have their own variety of indications, technical requirements and corresponding complications and should be carefully chosen. Total hip arthroplasty for advanced ONFH has positive results. It is generally considered that the long-term efficacy of cementless or mixed-type prosthesis is superior to that of cement prosthesis. The surgical skills required, efficacy and complications of arthroplasty for ONFH vary according to the presence of other disorders. The surgeon should note that: For patients with a long-term history of taking steroids for an underlying disease or some other reason, postoperative infection rates may be increased. For some patients with secondary osteoporosis who have not been weight-bearing for a long time, care should be taken to avoid penetrating the acetabulum during hip replacement surgery. For some patients with failure of a previous preservation procedure, it can be difficult to insert a femoral prosthesis. An arthrodesis procedure can be suitable for younger patients with advanced unilateral ONFH who engage in a lot of physical work. Stage 0: patients with non-traumatic unilateral ONFH who have a definite diagnosis and in whom it is strongly suspected that the opposite hip may also be affected should be closely observed. Assessment by MRI is suggested at 6 monthly intervals. Stages I and II: those asymptomatic patients whose necrotic area is located in a non-weight-bearing region and whose necrotic lesion area <15%, should be closely observed and followed up regularly. Some patients who are symptomatic, or whose necrotic lesion area >15%, should be actively treated. Stages III A and B: a variety of surgical options, including bone grafting, osteotomy, and limited surface replacement, may be selected. Some patients with mild symptoms may be treated conservatively. Stages III C and IV: some younger patients with mild symptoms can be treated by joint-preservation surgery. Other options include surface replacement, total hip replacement and hip arthrodesis. Evaluation of the efficacy of ONFH treatment includes clinical results and radiographic evaluation. Hip function scores (such as the Harris score, the revised Merle d'Auligne score and SF36 evaluation) should be used for evaluation of clinical results. In evaluating imaging results, X-ray films with a template of concentric circles should be used to observe the femoral head shape, joint gap and acetabular changes. For lesions of Stages 0, I, II, MR scanning should be performed. For each patient, the clinical and radiological results are not the same, and should be assessed separately. The Chinese version of this guideline has been published in the Chinese Journal of Orthopaedics, Issue 2, Volume 27, pages 146–148.

ObjectiveThis meta-analysis aimed to compare the relative safety and efficacy of cannulated compression screw (CCS) and femoral neck system (FNS) in treating patients with femoral neck fractures and to provide evidence-based medical evidence for FNS in treating femoral neck fractures.MethodsPubMed, Embase, Cochrane, and China National Knowledge Infrastructure databases were searched to collect outcomes related to femoral neck fractures treated with FNS and CCS, including time to fracture healing, incidence of non-union, incidence of osteonecrosis of the femoral head, incidence of failure of internal fixation, rate of femoral neck shortening, Harris hip score, Barthel index, operative time, intraoperative blood loss, fluoroscopy frequency, and complications. A meta-analysis was performed using RevManv5.4 (The Cochrane Collaboration) and Stata v14.0 software.ResultsThis analysis included 21 studies involving 1,347 patients. The results showed that FNS was superior to CCS in terms of fracture healing time [mean difference (MD) = −0.75, 95% CI = (−1.04, −0.46), P < 0.05], incidence of bone non-union [odds ratio (OR) = 0.53, 95% CI = (0.29, 0.98), P = 0.04], incidence of osteonecrosis of the femoral head [OR = 0.49, 95% CI = (0.28, 0.86), P = 0.01], incidence of internal fixation failure [OR = 0.30, 95% CI = (0.18, 0.52), P < 0.05], rate of femoral neck shortening [OR = 0.38, 95% CI = (0.27, 0.54), P > 0.05], Harris hip score [MD = 3.31, 95% CI = (1.99, 4.63), P < 0.001], Barthel index [MD = 4.31, 95% CI = (3.02, 5.61), P < 0.05], intraoperative bleeding [MD = 14.72, 95% CI = (8.52, 20.92), P < 0.05], fluoroscopy frequency [OR = 0.53, 95% CI = (0.29, 0.98), P = 0.04], and complications [OR = 0.31, 95% CI = (0.22, 0.45), P < 0.05]. The difference between FNS and CCS in operative time was not statistically significant [MD = −2.41, 95% CI = (−6.88, 2.05), P = 0.29].ConclusionFNS treatment of femoral neck fracture can shorten the fracture healing time; reduce the incidence and translucent rate of bone non-union, osteonecrosis of the femoral head, and internal fixation failure; reduce intraoperative blood loss and postoperative complications; and improve hip joint function and activity. We are confident in the findings that FNS, an effective and safe procedure for internal fixation of femoral neck fractures, is superior to CCS.

To analyze the correlation between postoperative complications and combined deflection angle classification adduction type (CDAC-ADT) of femoral neck fractures after cannulated screw internal fixation. The clinical data of 121 patients with CDAC-ADT femoral neck fracture admitted between January 2018 and December 2021 and met the selected criteria were retrospectively analyzed. There were 69 males and 52 females, the age ranged from 19 to 79 years (mean, 48.1 years). The causes of injury included 52 cases of traffic accident, 24 cases of falling from height, and 45 cases of fall. The time from injury to operation ranged from 2 to 12 days, with an average of 6.0 days. Among them, there were 18 cases of CDAC-ADT type Ⅰ, 46 cases of type Ⅱ, and 57 cases of type Ⅲ; 6 cases of Garden type Ⅱ, 103 cases of type Ⅲ, and 12 cases of type Ⅳ; and according to the location of the fracture line, there were 26 cases of subcapitate type, 88 cases of transcervical type, and 7 cases of basal type. All patients were treated with cannulated screw internal fixation. The occurrence of complications (including internal fixation failure, fracture nonunion, and osteonecrosis of the femoral head) was recorded, and the correlation between complications and CDAC-ADT typing, Garden typing, and fracture line location were analyzed. The patients were followed up 8-44 months, with a mean of 24.9 months. There were 10 cases of internal fixation failure, 7 cases of fracture nonunion, and 30 cases of osteonecrosis of the femoral head after operation. Correlation analysis showed that patients' CDAC-ADT typing was significantly correlated with the overall incidence of complication and the incidence of internal fixation failure, fracture nonunion, and osteonecrosis of the femoral head ( P<0.05), and the Pearson coefficient of contingency were 0.435, 0.251, 0.254, and 0.241, respectively. Garden typing did not correlate with the overall incidence of complication and the incidence of internal fixation failure and fracture nonunion ( P>0.05), but correlated with the incidence of osteonecrosis of the femoral head ( P<0.05), and the Pearson coefficient of contingency was 0.251. Fracture line position typing had no correlation with the overall incidence of complication and the incidence of internal fixation failure, fracture nonunion, and osteonecrosis of the femoral head ( P>0.05). CDAC-ADT typing has obvious correlation with postoperative complications of femoral neck fracture and can be used to predict complications of femoral neck fracture.

To investigate short-term effectiveness of robot-guided femoral neck system (FNS) combined with cannulated compression screw (CCS) fixation in treatment of femoral neck fracture in young and middle-aged patients. A clinical data of 49 young and middle-aged patients with femoral neck fractures, who met the selection criteria and admitted between January 2021 and June 2023, was retrospectively analyzed. After reduction of femoral neck fractures, 27 cases were treated with robot-guided FNS fixation (FNS group) and 22 cases with robot-guided FNS and CCS fixation (FNS+CCS group). There was no significant difference in baseline data such as gender, age, cause of fracture, time from fracture to operation, fracture side, and classification (Garden classification and Pauwels classification) between the two groups ( P>0.05). The operation time, intraoperative blood loss, intraoperative fluoroscopy frequency, the time when the patient began bearing weight, and hip joint pain and functional scores (VAS score and Harris score) at last follow-up for two groups were recorded. Imaging re-examination was taken to evaluate the quality of fracture reduction, fracture healing, as well as the occurrence of fracture non-union, osteonecrosis of the femoral head, and femoral neck shortening. All operations were successfully completed and the incisions healed by first intention. There was no significant difference in operation time and intraoperative blood loss between the two groups ( P>0.05), and the intraoperative fluoroscopy frequency in FNS+CCS group significantly increased compared to FNS group ( P<0.05). All patients were followed up 12-18 months (mean, 14.1 months). Imaging re-examination showed that there was no significant difference in fracture reduction quality between the two groups ( P>0.05), but the fracture healing time was significantly shorter in FNS+CCS group than in FNS group, and weight-bearing began earlier ( P<0.05). The incidences of femoral neck shortening, fracture non-union, and osteonecrosis of the femoral head were lower in FNS+CCS group than in FNS group, and there was significant difference in the incidence of femoral neck shortening between groups ( P<0.05). At last follow-up, there was no significant difference in VAS scores between the two groups ( P>0.05). However, the Harris score was significantly higher in FNS+CCS group than in FNS group ( P<0.05). Compared with FNS fixation alone, robot-guided FNS combined with CCS fixation in the treatment of femoral neck fractures in young and middle-aged patients has obvious advantages in terms of early weight bearing and fracture healing, improves fracture healing rate, effectively prevents postoperative complications, and can obtain good short-term effectiveness.

BackgroundThis study aimed to evaluate the clinical efficacy of the femoral neck system alone or in combination with a cannulated screw compared with other internal fixation methods for treating femoral neck fractures. We further investigated the predictive effects of tip-apex distance (TAD) on clinical efficacy.MethodsData from 129 young adults with femoral neck fractures followed up at The Second Affiliated Hospital of Fujian Medical University between January 2016 and June 2022 were retrospectively collected. The patients were categorized into four groups based on the different internal fixation methods. Analysis and comparisons of the four group were performed according to age, ASA score, operation time, blood loss, fracture classification, fracture healing time, Harris score, TAD value, presence of complications (osteonecrosis of the femoral head, screw failure, and femoral neck shortening), and changes in the neck-shaft angle.ResultsAll 129 patients were followed up for at least one year. The group who received treatment with the femoral neck system combined with a cannulated screw exhibited the shortest fracture healing time. Differences were observed in the change of neck-shaft angle among the four groups (P < 0.001), with the smallest change observed in the aforementioned group (0.76 ± 0.54°). The femoral neck shortening was also lower in groups with the femoral neck system or combined with a cannulated screw. At the last follow-up surgery, the combined treatment group achieved the highest HHS score. Subgroup analysis revealed that when the TAD was less than 25 and 49 mm for the femoral neck system and combined groups, respectively, there was less femoral neck shortening, less change in the neck-shaft angle, and a higher HHS score.ConclusionsThe femoral neck system alone or combined with a cannulated screw demonstrated better short-term efficacy in the treatment of femoral neck fractures. Furthermore, TAD may serve as a predictive indicator of the potential success of femoral neck fracture treatment.

Internal fixation has been established as a treatment of choice in relatively young patients with femoral neck fractures. Due to the characteristics of femoral neck anatomy and blood supply, complications such as malunion, nonunion, avascular necrosis, and femoral neck shortening can occur after internal fixation of femoral neck fractures. Unlike other complications such as avascular necrosis or nonunion, femoral neck shortening has not been relatively well studied. This study aimed to investigate the risk factors and clinical outcomes of femoral neck shortening after internal fixation of femoral neck fractures. From June 2012 to July 2022, among 102 patients who underwent internal fixation of femoral neck fractures, 94 patients who met inclusion and exclusion criteria were retrospectively analyzed. Internal fixation of the femoral neck was done with cannulated compression screws or a femoral neck system. Patients were divided into 2 groups; femoral neck shortening (≥ 5 mm) and no shortening (< 5 mm) according to measurement on follow-up hip anteroposterior (AP) simple radiographs compared with postoperative hip AP simple radiographs. Demographic and radiographic data were compared between the 2 groups. The modified Harris Hip Score (mHHS) and a visual analog scale (VAS) were used to evaluate the clinical outcomes. Among 94 patients, femoral neck shortening was observed in 33 (35.1%). In chi-square test, Pauwels angle, Garden type III or IV (displacement), and cortical comminution were significantly correlated with neck shortening (p < 0.05). In the multifactorial logistic regression test, cortical comminution was significantly correlated with femoral neck shortening (p < 0.01). The shortening group showed significantly lower clinical scores in terms of mHHS and VAS (p < 0.01). The femoral neck shortening group showed significantly lower clinical scores of mHHS and VAS than the no-shortening group. The presence of cortical comminution in preoperative hip computed tomography is a risk factor of femoral neck shortening after internal fixation of femoral neck fractures.

To explore the risk factors for osteonecrosis of the femoral head (ONFH) after treatment of femoral neck fractures with femoral neck system (FNS). Between January 2020 and February 2021, 179 patients (182 hips) with femoral neck fractures treated by FNS fixation were selected for retrospective analysis. There were 96 males and 83 females with an average age of 53.7 years (range, 20-59 years). There were 106 cases of low-energy-induced injury and 73 cases of high-energy-induced injury. The fractures were classified as type Ⅱ in 40 hips, type Ⅲ in 78 hips, and type Ⅳ in 64 hips according to Garden classification standard, and as typeⅠin 23 hips, type Ⅱ in 66 hips, and type Ⅲ in 93 hips according to Pauwels classification standard. There were 21 patients with diabetes. Patients were divided into ONFH group and non-ONFH group according to whether ONFH occurred at last follow-up. The data of the patients were collected, including age, gender, body mass index (BMI), trauma mechanism, bone mineral density, having diabetes or not, Garden classification and Pauwels classification of fractures, fracture reduction quality, femoral head retroversion angle, and removal of internal fixator or not. The above factors were analyzed by univariate analysis, and then multivariate logistic regression analysis was used to identify risk factors. Total 179 patients (182 hips) were followed up 20-34 months (mean, 26.5 months). Of these, 30 cases (30 hips) developed ONFH at 9-30 months after operation (ONFH group), and the incidence of ONFH was 16.48%. And 149 cases (152 hips) had no ONFH at last follow-up (non-ONFH group). The univariate analysis showed that there were significant differences between groups in bone mineral density, having diabetes or not, Garden classification, femoral head retroversion angle, and fracture reduction quality ( P<0.05). The multivariate logistic regression analysis showed that the Garden type Ⅳ fracture, reduction quality of grading Ⅲ, femoral head retroversion angle >15°, complicated with diabetes were the risk factors for ONFH after FNS fixation ( P<0.05). For the patients with Garden type Ⅳ fracture, poor quality of fracture reduction, femoral head retroversion angle >15°, and diabetes, the risk of ONFH after FNS fixation increases.

ObjectiveTo investigate the distribution and influence of comminution in femoral neck fracture (FNF) patients after cannulated screw fixation (CSF).MethodsFrom January 2019 to June 2020, a total of 473 patients aged 23–65 years with FNF treated by CSF were included in the present study. Based on location of the cortical comminution, FNF patients were assigned to two groups: the comminution group (anterior comminution, posterior comminution, superior comminution, inferior comminution, multiple comminutions) or the without comminution group. The incidence of postoperative complications, quality of life and functional outcomes was recorded at 1-year follow-up.ResultsComminution was more likely to appear in displaced FNF patients (86.8%) compared with non-displaced FNF patients (8.9%), and the rate of comminution was closely associated with Pauwels classification (3.2% vs 53.5% vs 83.9%, P < 0.05). The incidence of osteonecrosis of the femoral head (ONFH, 11.3% vs 2.9%, P < 0.05), nonunion (7.5% vs 1.7%, P < 0.05), femoral neck shortening (21.6% vs 13.4%, P < 0.05) and internal fixation failure (11.8% vs 2.9%, P < 0.05) was significantly higher in FNF patients with comminutions, especially with multiple comminutions, than those without. Furthermore, there was a significant difference in the Harris hip score (HHS, 85.6 ± 15.6 vs 91.3 ± 10.8, P < 0.05) and EuroQol five dimensions questionnaire (EQ-5D, 0.85 ± 0.17 vs 0.91 ± 0.18, P < 0.05) between FNF patients with comminution and those without. There was no significant difference in Visual analogue scale scores (VAS, 1.46 ± 2.49 vs 1.13 ± 1.80, P > 0.05) between two groups at 1 year post-surgery.ConclusionComminution is a risk factor for postoperative complications in young- and middle-aged patients with displaced and Pauwels type III FNF who undergo CSF. This can influence the recovery of hip function, thereby impacting quality of life. Further evaluation with a more comprehensive study design, larger sample and long-term follow-up is needed.

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. 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 1-3years after screw fixation. The occurrence of ONFH was investigated through plain radiography and MRI. 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 18.9months 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. 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.

To analyze the outcomes of patients with femoral neck fractures aged 50 years or older treated with Trochanteric Fixation Nail-Advanced (TFNA; DePuy Synthes, Paoli, PA) to determine the stability of fracture fixation and the effectiveness of the treatment. Design: Retrospective cohort study. Single level I trauma center. Patients aged 50 years or older who underwent fixation with TFNA helical blade for femoral neck fractures (OTA/AO 31-B) and were followed for more than 1 year were included. Radiological examinations were evaluated to determine bone union, femoral neck shortening, development of avascular necrosis (AVN) of the femoral head, and breakage of metal fixation. A comparison was made between patients with femoral neck shortening (>5 mm) and those without (<5 mm). A total of 45 patients were included in this study. The mean age of the patients was 70.2 (50-89) years, and 68.9% were females. No early postoperative complications, such as postoperative infection, deep vein thrombosis, or pulmonary embolism, were observed. All patients achieved bone union within 23 weeks. The average femoral neck shortening was 2.6 mm (0-16.8), with femoral neck shortening >5 mm observed in 7 patients (15.6%). Significant femoral neck shortening was observed in patients with displaced fractures compared to non-displaced fractures (p=0.006). One patient developed AVN of the femoral head. No metal fixation failure was observed. In patients aged 50 years or older, TFNA fixation for non-displaced femoral neck fractures demonstrated relatively minimal femoral neck shortening and a low complication rate, indicating that it is an effective technique for treating these fractures. However, for displaced fractures, surgeons should be mindful of the potential for excessive neck shortening and carefully select the surgical method. Therapeutic Level III.

ABSTRACTObjectiveIf the appropriate internal fixation surgical method is not adopted for femoral neck fractures in young people, it may lead to serious consequences such as poor fracture healing and femoral head necrosis, affecting the quality of life and working ability of young people. Therefore, it is crucial to conduct in‐depth research on the internal fixation surgical methods. This study compared the therapeutic effects of triple cannulated screws combined with a bone graft sleeve for parallel implantation of DBM Crunch internal fixation (CCSBGS) and cannulated compression screws (CCS).MethodsMedical records on the young and middle‐aged patients with femoral neck fracture treated with two different internal fixation methods from January 2020 to June 2023 were collected and retrospectively analyzed in the Trauma Emergency Center of the Third Hospital of Hebei Medical University. Two internal fixation groups are: CCSBGS group with 50 patients, 35 males and 15 females, aged (42.44 ± 14.07) years; CCS group with 80 males and 39 females, aged (41.5 ± 13.48) years. This study compared the outcome measures of two groups of patients, including Garden alignment index, Operation duration time, Intraoperative blood loss, Length of hospital stay, Postoperative complications, Femoral neck shortening, Postoperative ambulation time, Walking with sticks, Barthel score, and Harris score.ResultsThere was a statistically significant difference in blood loss between the CCS group and the CCSBGS group; at the same time, the amount of bleeding in the CCS group was lower than that in the CCSBGS group (p < 0.01). During the follow‐up period, there was a statistically significant difference in the incidence of osteonecrosis of the femoral head among the two groups (p < 0.05), 20 patients in the CCS group and 2 patients in the CCSBGS group developed osteonecrosis of the femoral head. At the last follow‐up, the average degree of femoral neck shortening in the CCSBGS group [(0.49 ± 0.28) cm] was significantly lower than that in the CCS group [(0.87 ± 0.35) cm] (p < 0.05). Meanwhile, the postoperative ambulation time of the CCSBGS group is earlier than that of the CCS group (p < 0.05). In addition, the CCSBGS group had the highest Barthel scores [(95.50 ± 2.90)] (p < 0.05). The average Harris score in the CCSBGS group [(92.52 ± 2.41)] was higher than that in the CCS group [(90.47 ± 2.88)] (p < 0.05).ConclusionsCompared with CCSBGS and CCS, CCSBGS shows better efficacy in terms of quicker return to weight‐bearing activities, preservation of femoral neck length, reduction of the rate of osteonecrosis of the femoral head, and overall enhancement of hip function.