The Efficacy of a Double Wiring Technique in Cementless Hemiarthroplasty for Unstable Basicervical Intertrochanteric Fractures: A Propensity Score-Matched Analysis of Femoral Neck Fractures

Abstract

Background

Basicervical intertrochanteric (IT) fractures are a distinct subtype of proximal femoral fractures, characterized by marked rotational instability and a high risk of fixation failure. In elderly patients, primary arthroplasty may serve as a viable option. This study aimed to report the clinical outcomes of cementless hemiarthroplasty using a double wiring technique for unstable basicervical IT fractures in elderly patients and to compare them with those after cementless hemiarthroplasty for displaced femoral neck (FN) fractures.

Methods

We retrospectively reviewed 45 patients aged 75 years and older who received cementless bipolar hemiarthroplasty using a double wiring technique for unstable basicervical IT fractures and were followed up for more than 1 year between January 2015 and December 2022. After propensity score matching (2 : 1), the control group comprised 90 patients who underwent cementless hemiarthroplasty for displaced FN fractures. All operations were performed via a short external rotator-preserving posterolateral approach. The perioperative results, postoperative complications, and 1-year mortality of the 2 groups were investigated and compared.

Results

The IT group exhibited significantly longer operation times (p = 0.031) and greater total blood transfusion volume (p = 0.027) than the FN group despite no significant differences in blood loss and transfusion rate. No significant differences were observed in postoperative medical and surgical complications. Wire breakage occurred in 7 patients, and of those, 5 showed proximal migration of the greater trochanter fragment. However, there was no subsequent functional impairment in these patients. At 1 year after the index surgery, there were no significant differences in walking ability and mortality rate between the 2 groups.

Conclusions

Cementless hemiarthroplasty with a double wiring technique for unstable basicervical IT fractures demonstrated clinical outcomes and 1-year mortality equivalent to those of hemiarthroplasty for displaced FN fractures, suggesting it as a feasible and safe option in osteoporotic elderly patients with these fractures.

Basicervical intertrochanteric (IT) fractures of the proximal femur have been reported to be a specific type of trochanteric fracture as a separate entity. The fracture line crosses close to the base of the femoral neck (FN) and its junction with the IT region compared with typical IT fractures.¹,²⁾ These fractures exhibit inherent rotational instability of the proximal fragment, attributed to the narrow base of the proximal fragment and subsequent narrower contact area at the main fracture site compared to conventional IT fractures.²,³⁾ Moreover, in unstable basicervical fracture types accompanied by trochanteric comminution and/or a large posteromedial fragment, the rotational instability of the proximal fragment after osteosynthesis may increase even more.⁴⁾

Several advantages of cephalomedullary nailing (CMN) have led to increased use for most pertrochanteric fractures including cases with basicervical fracture patterns.⁵,⁶⁾ However, Watson et al.³⁾ reported that all fixation failures after CMN for basicervical proximal femoral fractures developed in patients who had an appropriate tipapex distance < 25 mm and anatomic or nearly anatomic reduction, and suggested that factors other than surgical technique were probably responsible for the failures. Ciufo et al.⁷⁾ reported that a basicervical fracture component, as well as a lateral wall fracture along with trochanteric comminution, are risk factors associated with cut-out after CMN in pertrochanteric fractures. For frail elderly patients, failed fixation of IT fractures often necessitates complex revision surgery, which is associated with a dramatic decline in functional outcomes and increased rates of morbidity and mortality.⁸,⁹⁾ Accordingly, IT fractures in these patients should be managed with a single definitive procedure whenever possible, and primary arthroplasty can be a useful alternative for unstable basicervical IT fractures with a high risk of fixation failure.¹⁰⁾

Consequently, primary hemiarthroplasty has emerged as a compelling alternative for managing unstable basicervical IT fractures in osteoporotic elderly patients. However, performing cementless hemiarthroplasty in this context remains technically demanding due to the difficulty of achieving stable stem fixation and restoring the abductor mechanism in the presence of extensive trochanteric comminution. Our double wiring technique was designed to address these problems simultaneously and mimic the intact proximal femoral anatomy found in FN fractures. Therefore, to evaluate the clinical success of this approach, it was necessary to compare it against displaced FN fractures, which are the established standard for hemiarthroplasty in the elderly.

This study aimed to introduce a simplified double wiring technique during cementless hemiarthroplasty for unstable basicervical IT fractures and report its clinical efficacy by comparing it with a cohort undergoing hemiarthroplasty for FN fractures, thereby validating it as a reliable definitive procedure for these complex fractures. We hypothesized that cementless hemiarthroplasty using a double wiring technique for unstable basicervical IT fractures would achieve clinical outcomes and mortality rates comparable to those of standard hemiarthroplasty for displaced FN fractures in the elderly.

METHODS

This retrospective case-control study was approved by the Institutional Review Board of Hallym University Sacred Heart Hospital (IRB No. 2022-10-027). The requirement for informed consent was waived owing to its retrospective nature.

This study utilized a prospectively compiled database to retrospectively evaluate patients aged 75 years and older who received cementless bipolar hemiarthroplasty using double wiring for unstable basicervical IT fractures at our hospital between January 2015 and December 2022. During this period, CMN was also performed in these fractures with minimal comminution not requiring double wiring, and hemiarthroplasty with double wiring was performed only in unstable basicervical IT fractures with detached greater trochanter (GT) fragment or large posteromedial fragment or comminution of GT or anterior cortex of the proximal fragment. Finally, throughout the study period, 58 patients (58 hips) were identified. Basicervical IT fracture was defined as a fracture in which the main fracture line of the proximal fragment crossed close to the base of the FN and its junction with the trochanteric region.¹,¹¹⁾ To ensure diagnostic accuracy and minimize the impact of the heterogeneous nature of basicervical IT fractures, all cases were evaluated using a standardized imaging protocol. All fractures were classified by 2 independent authors (DKK and JHH) according to the AO Foundation/Orthopaedic Trauma Association (AO/OTA) classification system¹²⁾ and the presence of a basicervical fracture component was strictly confirmed on standard radiographs and 3-dimensional computed tomography (3D CT) scans taken before surgery. The use of both radiographs and 3D CT was intended to improve diagnostic consistency. Two-part basicervical neck fractures confirmed on 3D CT were excluded as these were considered variants of FN fractures. Finally, AO/OTA 31-A2 IT fractures with a basicervical fracture component were included in the study group. Any discrepancies in classification between the 2 reviewers were resolved through a consensus-based re-evaluation of the 3D CT reconstructions and this process minimized potential misclassification.

Based on the same data source, 348 patients (360 hips) who had received cementless hemiarthroplasty by the same surgeon for a displaced FN fracture during the same period were identified. Thirteen patients in the IT group and 80 patients in the FN group were excluded, respectively, as they were not followed up for over 1 year and their details, including death, could not be confirmed. Consequently, the population consisted of 45 patients (IT group) and 268 patients (FN group) available for analysis at all designated time points.

To compare the IT group (study group) with the FN group (control group), a 2:1 propensity score matching ratio was utilized and the final analysis included 45 patients in the IT group and 90 matched patients out of 268 in the FN group. To ensure balanced baseline characteristics, patients were matched based on 7 key clinical and demographic variables: age, sex, body mass index, bone mineral density, American Society of Anesthesiologists score, time from admission to operation, and pre-injury ambulation status. The mean age of the patients in the IT group and FN group were 85.8 ± 8.3 years and 84.7 ± 6.9 years, respectively. No significant differences in the demographic variables including age were observed between the 2 groups (Table 1). Finally, the success of the propensity score matching was confirmed by the statistically homogeneous distribution of all demographic variables between the 2 groups, effectively minimizing selection and indication bias. The mean follow-up period was 19.4 ± 16.5 months and 21.0 ± 16.1 months for the IT and FN groups, respectively.

Table 1. Demographic and Clinical Characteristics in Both Groups.

Variable		Study group (n = 45)	Control group (n = 90)	p-value
Age (yr)		85.8 ± 8.3	84.7 ± 6.9	0.882
Sex (female : male)		34 : 11	72 : 18	0.921
Body mass index (kg/m2)		22.7 ± 3.6	22.4 ± 3.5	0.915
BMD (T-score, femur neck)		–3.0 ± 0.8	–2.9 ± 0.7	0.405
ASA score				0.874
	II	0	1 (1.1)
	III	35 (77.8)	74 (82.2)
	IV	10 (22.2)	15 (16.7)
Time to operation (day)		3.3 ± 4.1	3.2 ± 3.7	0.745
Preoperative level
	Hb (g/dL)	11.0 ± 1.7	11.7 ± 1.9	0.801
	Hct (%)	33.5 ± 3.8	34.7 ± 4.4	0.903
Preoperative functional (Koval) score		4.7 ± 1.3	4.4 ± 1.4	0.787
Follow-up (mo)		19.4 ± 16.5	21.0 ± 16.1	0.748

Values are presented as mean ± standard deviation or number (%).

BMD: bone mineral density, ASA: American Society of Anesthesiologists, Hb: hemoglobin, Hct: hematocrit.

All surgical procedures were performed using a posterolateral approach preserving the short external rotators by a single senior surgeon (JHY).¹³⁾ All femoral components were inserted in a press-fit manner using a midshort or conventional tapered-wedge cementless stem: Tri-Lock stem (DePuy Synthes), Accolade II stem (Stryker), or Ecofit stem (Implantcast). The rectangular geometry of these stems affords sufficient rotational stability even in the weak osteoporotic femur. The acetabular component used in our patients was a cobalt-chromium cup (IC Bipolar Head, Implantcast), which had an ultrahigh-molecularweight polyethylene liner inside.

After rasping the endosteal cavity of the proximal femur, we used a stem trial to check the stem size, stability, and leg length. During the operation, in all patients, the GT was fractured off from the proximal fragment along with the medial calcar fragment, which did or did not include the lesser trochanter (LT). Accordingly, prophylactic cerclage wiring just above or below the LT using two 16-gauge monofilament steel wires was first performed to obtain the initial press-fit of the stem and prevent intraoperative calcar fracture (Fig. 1A). Then, the selected stem was inserted into the femoral canal with firm impaction from gentle tapping to achieve a press-fit. Next, 1 end of the 2 wires used for cerclage wiring of the proximal femur was passed just below the abductor tendons at the GT tip, and the GT fragment was securely stabilized by tightening the both ends of each wire on the contralateral side (Fig. 1B). The ends of each tightened wire were bent and buried in the muscle to avoid soft-tissue irritation (Fig. 1C). In all cases, the short external rotators were preserved during surgery, and the posterior capsule was routinely repaired.

Fig. 1. (A) Schematic image and intraoperative photograph of 2 cerclage wires just below the lesser trochanter (asterisk). (B) Schematic images and an intraoperative photograph showing double wiring passed just medial to the abductor tendon (arrowhead) with 2 wires used for cerclage wiring to fix the greater trochanter fragment and preserve the abductor mechanism. (C) Intraoperative photograph after completion of double wiring.

Postoperatively, all patients received standard medical care, with assisted mobilization and tolerable weightbearing initiated on the second postoperative day using appropriate assistive devices. In the absence of contrain-dications, the patients were given low-molecular-weight heparin for 1 week as a means of thromboprophylaxis, along with anti-embolic stockings. Patients who required further physical therapy or nursing care were transferred to the rehabilitation department or other institutions.

Follow-up evaluations were performed at 6 weeks, at 3, 6, and 12 months, and every year thereafter. Electronic records were retrospectively reviewed and analyzed for demographic data, blood loss, amount and rate of transfusion, operative time, and postoperative medical and surgical complications. During the postoperative period, patients received transfusion of packed red blood cells (RBCs) when the hemoglobin level decreased below 8 g/dL or at higher levels if a poor general condition, palpitations, dizziness, or pallor was observed. The estimated blood loss (EBL) was calculated according to the Gross formula, as shown below.

Prediction of blood volume:¹⁴⁾

Males: 604 + 0.0003668 × [height (cm)]³ + 32.2 × weight (kg)

Females: 183 + 0.000356 × [height (cm)]³ + 33 × weight (kg)

EBL calculation method:¹⁵⁾

EBL = blood volume × (Hematocrit_preoperative – Hematocrit_{day 5 postoperative}) + volume of transfused RBC (mL).

Stem subsidence was evaluated by comparing the immediate postoperative radiographs with the final follow-up radiographs. The distance from the tip of the GT (or a reproducible cortical landmark when the GT was fragmented) to a constant point on the femoral stem (the proximal shoulder of the stem) was measured. Measurements were calibrated using the known diameter of the prosthetic femoral head to correct for radiographic magnification. The difference between immediate postoperative and final follow-up radiographs was recorded as stem subsidence. All measurements were performed by the same 2 independent authors, and the mean values were utilized for analysis to ensure data reliability.

Walking ability (Koval score) and Harris hip score (HHS) were assessed at 1 year after the index operation for functional evaluation and 1-year mortality was investigated.

Statistical Analysis

Categorical variables were reported as frequencies and percentages. Continuous variables were reported as the mean with standard deviation. We compared continuous data using Student t-test and categorical data using the chi-square test. Statistical significance was determined as obtaining a p-value < 0.05 in all the analyses. Data analysis was performed using IBM SPSS version 24 (IBM Corp.).

RESULTS

The IT group required a significantly longer operative time compared to the FN group (p = 0.031). Furthermore, the total volume of blood transfusion was significantly higher in the IT group (p = 0.027). However, no significant differences were observed between the 2 groups regarding blood loss and the overall transfusion rate (Table 2). There were no significant differences in the incidence of postoperative medical and surgical complications between the 2 groups (Table 3). Notably, neither group experienced major adverse events such as dislocation, surgical site or periprosthetic joint infection, stem loosening, or periprosthetic fracture during the follow-up period. Additionally, stem subsidence showed no significant difference, with mean values of 1.35 ± 1.32 mm for the IT group and 1.37 ± 1.51 mm for the FN group (p = 0.96).

Table 2. Comparison of Perioperative Data between the Two Groups.

Variable	Study group (n = 45)	Control group (n = 90)	p-value
Operation time (min)	94.9 ± 22.1	74.8 ± 21.1	0.031
Immediate postoperative Hb (g/dL)	10.1 ± 1.3	10.5 ± 1.4	0.779
Immediate postoperative Hct (%)	29.7 ± 4.5	32.45 ± 3.59	0.569
Estimated blood loss (mL)	961.0 ± 728.7	758.6 ± 514.4	0.106
Total transfusion volume (mL)	1003.5 ± 917.0	574.3 ± 401.5	0.027
Transfusion rate	88.9 (40)	76.7 (69)	0.135

Values are presented as mean ± standard deviation or percentage (number).

Hb: hemoglobin, Hct: hematocrit.

Table 3. Postoperative Complications in Both Groups.

Variable		Study group (n = 45)	Control group (n = 90)	p-value
Medical complication				0.872
	Cardiovascular	32	75
	Pulmonary	17	35
	Cerebrovascular	6	15
	Nephrologic	22	42
	Urologic	23	29
	Gastrointestinal	17	33
Surgical complication				0.999
	Dislocation	0	0
	PJI and surgical site infection	0	0
	Stem loosening	0	0
	Periprosthetic fracture	0	0

PJI: periprosthetic joint infection.

In the IT group, wire breakage was identified in 7 patients during follow-up, 5 of whom exhibited proximal migration of the GT fragment. Importantly, these radiographic findings did not result in subsequent functional impairment. Only 1 patient required the removal of a broken wire due to localized discomfort from soft-tissue irritation. At 1 year after the index surgery, the functional outcomes assessed via Koval score and HHS yielded no significant differences between the 2 groups (p = 0.71 and 0.88, respectively). Finally, the 1-year mortality rate was comparable between the groups, with 24.4% in the IT group and 27.8% in the FN group (p = 0.66) (Table 4).

Table 4. Comparison of Walking Ability and Mortality at 1 Year after Surgery.

Variable	Study group (n = 45)	Control group (n = 90)	p-value
Functional (Koval) score	2.84 ± 1.11	2.45 ± 1.12	0.712
Harris hip score	68.4 ± 7.5	69.2 ± 6.7	0.875
1-Year mortality	11 (24.4)	25 (27.8)	0.664

Values are presented as mean ± standard deviation or number (%).

DISCUSSION

In unstable IT fractures, the presence of a basicervical fracture component has been identified as a significant risk factor for fixation failure such as cut-out.⁷,¹⁶⁾ Such failures often necessitate complex reoperations, which significantly increases functional decline, morbidity, and mortality among frail elderly patients, while also imposing a substantial socioeconomic burden.⁸,¹⁷⁾ While CMN is a standard treatment, the inherent rotational instability of the proximal fragment and poor bone quality in basicervical patterns frequently compromise its success. Consequently, primary hemiarthroplasty has emerged as a viable alternative to internal fixation, such as CMN for these patients, offering the advantages of immediate weight-bearing and eliminating the complications related to fixation failures such as collapse or cut-out.¹⁸,¹⁹,²⁰,²¹⁾ However, the technical execution of cementless hemiarthroplasty in unstable basicervical IT fractures remains formidable due to extensive fracture comminution and poor bone quality.²²,²³,²⁴⁾ In this study, we introduced a simplified double wiring technique designed to stabilize the GT fragment and ensure the safe implantation of a cementless stem in unstable basicervical IT fractures, comparing its clinical outcomes with those of hemiarthroplasty for displaced FN fractures.

Unstable IT fractures with a basicervical pattern are more prevalent in the elderly osteoporotic population and are frequently characterized by the detachment of the GT fragment along with the medial calcar fragment including the LT.⁶,²⁵⁾ Performing cementless hemiarthroplasty in such cases presents challenges comparable to osteosynthesis. The surgeon must overcome 2 primary challenges: achieving a stable, press-fit stem fixation without inducing intraoperative calcar fractures in a comminuted proximal femur and restoring the abductor mechanism by securely fixing the GT fragment. Our proposed double wiring technique was specifically designed to address these issues simultaneously. First, the use of 2 wires for prophylactic cerclage reinforces the proximal femur prior to stem insertion. This step is crucial for preventing intraoperative calcar fracture, a common complication when impacting a cementless stem into osteoporotic bone. By securing the proximal femur first, the surgeon can achieve the necessary press-fit stability required for early mobilization. Second, the dual function of these wires allows for the anatomical restoration of the GT fragment. By passing the wires just below the abductor tendons and tightening them, the abductor mechanism is effectively reconstituted, which is vital for postoperative gait stability and preventing abductor weakness. Our results demonstrate that this approach effectively prevents intraoperative calcar fractures and postoperative stem subsidence or loosening. (Fig. 2).

Fig. 2. (A) Initial radiograph and 3-dimensional computed tomography scans of an 88-year-old man showing an unstable basicervical intertrochanteric fracture. (B) Anteroposterior and lateral radiographs at final follow-up (2 years after surgery) after hemiarthroplasty using a double wiring technique.

This study evaluated the clinical outcomes, including postoperative complications and 1-year mortality, of our double wiring technique in patients aged 75 years and older. We found no significant differences between the IT and FN groups regarding postoperative complications, functional recovery, and survival rates. These findings suggest that cementless hemiarthroplasty using double wiring is a reliable and feasible modality for unstable basicervical IT fractures, yielding results comparable to those of primary hemiarthroplasty for displaced FN fractures in the osteoporotic elderly. Meanwhile, a notable finding in our study was the occurrence of wire breakage in 18.4% of cases, often accompanied by proximal migration of the GT fragment.

However, these radiographic findings did not translate into functional impairment. This suggests that the double wiring provides sufficient temporary stability during the critical early healing phase, allowing for bony or fibrous union before any hardware failure occurs. Furthermore, compared to bulkier hardware like grip plates, this wiring technique minimizes soft-tissue irritation, with only 1 patient in our cohort requiring wire removal.

The IT group required significantly longer operative times and higher transfusion volumes due to the complexity of the fracture, reflecting the inherent technical complexity of managing comminuted GT fragments and the necessity of additional prophylactic wiring. Nevertheless, the clear advantage of this technique lies in significantly mitigating the risks of fixation failure and subsequent reoperations in high-risk patients. By ensuring structural integrity, this procedure facilitates immediate weight-bearing and an accelerated rehabilitation protocol, which may ultimately shorten hospital stays and alleviate the socioeconomic burden.²⁶,²⁷⁾ Furthermore, the long-term clinical benefits—characterized by 1-year mortality and functional outcomes equivalent to those of displaced FN fractures—provide strong justification for this surgical approach. These findings suggest that cementless hemiarthroplasty combined with double wiring can effectively transform a high-risk, unstable basicervical IT fracture into a manageable clinical entity, yielding a postoperative trajectory comparable to that of a standard FN fracture.

The current study is limited by its retrospective nature despite prospectively collected data and a short-term follow-up with a relatively small number of patients. However, long-term follow-up is rarely possible with limited clinical relevance for the elderly, given their shorter life expectancy and the observation that functional recovery typically plateaus within 6 months after hip fracture surgery. Second, unstable IT fractures with a basicervical fracture component are relatively uncommon and CMN has also been performed in these fractures with minimal comminution. Accordingly, because primary hemiarthroplasty was selectively performed for these fractures with greater comminution, indication bias cannot be completely excluded. However, this selection reflects real-world clinical practice, and such bias would be expected to disadvantage the IT group. The comparable outcomes observed therefore suggest that cementless hemiarthroplasty with double wiring is a reliable option even in more complex fracture patterns. Third, the measurement of stem subsidence may be subject to a degree of error. While we attempted to mitigate this by using reproducible cortical landmarks in cases of GT fragmentation and employing 2 independent reviewers, the inherent displacement and comminution of the GT in unstable basicervical IT fractures may still affect the precision and reliability of these radiographic assessments compared to more stable fracture patterns. Fourth, the advanced age of our study population (mean age > 85 years) introduces inherent challenges in assessing functional outcomes. While we utilized standardized metrics such as the Koval score and HHS, these assessments may be confounded by preexisting factors common in the very elderly, including cognitive impairment, comorbidities, and diminished pre-injury mobility. These baseline variables may mask the true mechanical efficacy of the surgical technique and introduce measurement bias. Consequently, the functional scores reported in our study should be interpreted within the context of the overall physiological reserve and frailty of this specific geriatric cohort. Finally, while the single-surgeon, single-center design minimized surgical variability and ensured technical consistency, this may limit the generalizability of our results. Clinical outcomes achieved in our study are inherently related to the surgeon’s proficiency with the specific steps of the double wiring technique. Consequently, the learning curve associated with these technical nuances may influence outcomes in other clinical settings, and further multi-center studies are warranted to validate the reproducibility of this technique across varying levels of surgical experience.

Nevertheless, this study is uniquely strengthened by being the inaugural case-control analysis to feature matched patients, thereby minimizing surgical variability through a single-surgeon, single-center design within the same timeframe. The study is further strengthened by the statistically homogeneous distribution of demographic variables between the 2 groups.

In conclusion, cementless hemiarthroplasty with the double wiring technique for unstable basicervical IT fractures in osteoporotic elderly patients demonstrated clinical outcomes and mortality rates equivalent to those observed in hemiarthroplasty for displaced FN fractures. This approach serves as an effective and accessible treatment strategy for managing unstable basicervical IT fractures in the osteoporotic elderly population.