Percutaneous Cerclage Wiring As An Adjunct To Intramedullary Nailing In Fixation Of Subtrochanteric Femur Fractures
A Leung, Y Mak
Citation
A Leung, Y Mak. Percutaneous Cerclage Wiring As An Adjunct To Intramedullary Nailing In Fixation Of Subtrochanteric Femur Fractures. The Internet Journal of Orthopedic Surgery. 2025 Volume 32 Number 1.
DOI: 10.5580/IJOS.57327
Abstract
Introduction: Subtrochanteric femur fractures are frequently encountered proximal femur fractures and present significant surgical challenges due to strong deforming forces. While cephalon-medullary nailing is the preferred fixation method, achieving a good reduction remains difficult. Percutaneous cerclage wiring has emerged as a minimally invasive adjunct to improve reduction and stability, though concerns persist about its impact on fracture biology.
Methods: This retrospective single centre study evaluated 35 patients with subtrochanteric fractures, classified according to Russel-Taylor classification and treated with intramedullary nailing and percutaneous cerclage wiring between 2014 and 2022. Primary outcomes included union rate (by means of RUSH score) and reduction quality (by Baumgaertner criteria). Secondary outcomes included operative time, blood loss, complications, and revision rates.
Results: The union rate was 94.3% (33/35), with mean RUSH scores of 21.3 (±4.6) at 6 months and 27.1 (±2.9) at 12 months. Reduction quality was good in 77.1% (27/35) and satisfactory in 20% (7/35). 2 cases of non-union were found and required revision operation and fixation. Mean operative time was 136.1 minutes, with 477mL blood loss. No neurovascular injuries or infections were observed.
Conclusion: Percutaneous cerclage wiring as an adjunct to intramedullary nailing led to high union rates and excellent reduction quality in subtrochanteric fractures, with minimal complications. Meticulous surgical technique is critical to avoid mal-reduction and non-union, and other complications.
Introduction:
Subtrochanteric fractures of the femur are increasingly encountered during daily orthopaedic practice, accounting up to 5 -30% of proximal femur fractures. Subtrochanteric fractures often pose operative challenges due to the regional anatomy. Multiple strong deforming forces are produced by surrounding musculature, including the abductors, iliopsoas and external rotators which result in proximal fracture displacement, whereas the adductors cause distal fragment displacement. Combined together, these deforming forces combined can lead to significant difficulties in obtaining a satisfactory reduction and subsequent fracture union[ii].
Cephalo-medullary nailing is frequently the preferred mode of fixation for subtrochanteric fractures. It is imperative to ensure an adequate reduction before proceeding with fixation. Certain adjunct manoeuvres including open reduction and use of cerclage wiring can be used to aid and provisionally maintain the reduction. However, open reduction with cerclage has historically raised concerns regarding excessive stripping of the periosteal blood supply and hindering callus formation[iii][iv], and also concerns over surgical wounds leading to added complications. As a result, percutaneous cerclage wiring has also recently been adopted, with the benefit of minimising soft tissue trauma and decreasing the amount of periosteal stripping.
As a result, we suggest that percutaneous cerclage as an adjunct to intramedullary fixation of subtrochanteric or unstable long intra-trochanteric fractures will result in union of fractures with good quality reduction. Primary outcomes will include studying the rate of union and the quality of reduction by means of using RUSH and Baumgartner scores. Other outcomes including non-union, implant breakage and revision surgery, infection, operative time, blood loss amongst other outcomes will also be analysed.
Methods and Materials
This was a retrospective single centre case series between 1st September 2014 and 31st October 2022 at a regional district hospital in Hong Kong. Inclusion criteria included patients who suffered from acute subtrochanteric fractures (AO/OTA 32) within 5cm of the lesser trochanteric region, and unstable intertrochanteric fractures with subtrochanteric extension (AO/OTA 31). Classification was made according to the Russell-Taylor Classification. Patients who underwent intramedullary nailing (implants used: Synthes PFNa II, Stryker Gamma Nail 3, Expert A2FN 2) with additional adjunct percutaneous cerclage wiring were included in the study. Fractures such as those extending more distally to the femur shaft or proximally involving the femoral head or neck were excluded. Cases with inadequate follow up time (less than 6 months), atypical femoral fractures arising from bisphosphonate usage, pathological fractures secondary to primary tumour or metastasis, and fractures occurring in skeletally immature patients were all excluded from the study.
The primary aim of this study was to evaluate whether the usage of adjunctive cerclage wiring would affect healing of the fracture due to the aforementioned concerns about iatrogenic disruption of fracture site biology and vascularity. Fracture healing was evaluated by means of RUSH score (Radiographic Union Score for Hip), a validated score for quantification of radiographic healing of proximal femur fractures[ii].
The RUSH score was calculated through assessment of 4 measurements: cortical bridging, cortical fracture disappearance, fracture line consolidation and fracture line disappearance, with minimum score of 10 to a maximum score of 30. A score of >18 at 6 months has been shown to be a reliable indicator of fracture healing[iii].
Another outcome measure was assessment of the quality of fracture reduction after percutaneous cerclage wiring, which was evaluated using Baumgaertner Reduction Quality Criteria[iv],[v]. Assessment of alignment (AP normal or slightly valgus neck shaft angle; lateral < 20 degree angulation) and the degree of displacement (80% cortical overlap and <5mm shortening) were the determinants of the quality of fracture reduction. Both alignment and displacement criteria being fulfilled denoted a good reduction; only 1 criteria fulfilled was deemed satisfactory reduction; neither criteria fulfilled resulted in a poor quality of reduction finding. Radiographs were reviewed by a surgeon with more than 5 years of orthopaedic experience.
Other secondary outcomes studied included number of cerclage wires utilised, operative time, intra-operative blood loss, post operative tip-apex distance, post operative radiographic femur neck-shaft angle, subsequent need for revision surgery and other complications such as vascular injury, wound infection and others.
Statistical analysis was performed with Microsoft Excel and SPSS v16 software. Comparison among variable was done using Chi-Square test, Fisher’s exact test and Mann-Witney U test. Statistical significance was set as p <0.005.
Surgical technique and Protocol
All cases were admitted emergently via Accident and Emergency Department, with no cases performed after elective admission. Surgical protocol included closed reduction on traction table providing longitudinal traction, followed by appropriate adjustment of internal / external rotation and abduction/adduction to counteract the deformities. If suboptimal reduction was still noted, percutaneous cerclage wiring was then performed. A lateral incision less than 5cm long was made over the proximal lateral thigh corresponding to the fracture site. When possible, the same wound for the blade / hip screw was utilised, however in certain cases the wound required extension or even a separate incision. After incision of the fascia lata and dissection of the lateral thigh musculature, mini-open reduction was performed using instruments such as reduction forceps, Verbugge clamps, collinear clamps, or bone spikes and hooks to ensure satisfactory alignment. A minimally invasive percutaneous cerclage set was then used to encircle the femur over the anterior and posterior aspects respectively. A 30G steel wire was then passed, twisted, and tensioned in to an appropriate degree, then bent and cut short. Fluoroscopy was performed to confirm satisfactory application of the cerclage wire and to ensure that the reduction remained acceptable without further reduction. Antegrade nailing was thereafter performed in the usual manner via entry from the greater trochanter tip, with insertion of appropriately positioned and sized nail and lag screw. Traction was released, rotational alignment adjusted and distal locking screw inserted. Post operatively, patients were given 3 doses of intravenous antibiotic, as well as adequate analgesics. Limb mobilisation and physiotherapy was performed post operatively, with appropriate weight bearing walking exercises commenced after fixation was confirmed on post operative radiographs.
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Results
A total of 35 patients were included in this study. Prior to this, 4 patients were excluded due to atypical femoral fractures and 1 patient excluded due to pathological fracture. 1 case of paediatric trauma in a skeletally immature patient was also excluded. 5 patients were lost to follow up before the minimum study duration and were also excluded from the study. Among our final patient population, 23 were female and 12 were male. The mean age of patient was 77 years old.
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33 cases of union were established (94.3%) with 2 cases of non-union (5.7%). Mean RUSH scores were 21.3 (± 4.6) at 6 months and 27.1 (±2.9) at 12 months, whereby a RUSH score >18 at 6 months would suggest radiographic union. With the use of minimally invasive percutaneous cerclage was performed, the quality of reduction was deemed to be good in 27 cases (77.1%), satisfactory in 7 (20%), and poor in 1 case (2.9%).
The mean operative time was 136.1 (SD ±46.9) minutes and estimated blood loss 477 (SD ± 382) ml. The post-operative tip apex distance mean was 19.8 (SD ± 4.6). 77% of operative cases achieved a TAD <25mm and 23% had a TAD ³25mm. The immediate post operative neck shaft angle mean was 130.8 (SD ± 4) degrees.
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In total, 2 cases of non-unions were found. The first case of non-union was found to have varus malalignment during initial post-op radiographs, and the cerclage wire noted to have slipped and become interposed at the fracture site without adequately capturing the medial butterfly fragment. Close radiographic and clinical assessments were performed, and confirmed to have non-union at follow up after 6 months. The patient finally agreed for revision fixation, which was performed with dynamization of the long cephalon-medullary nail, removal of the interposed cerclage wire, fracture site debridement and addition of Bone Morphogenetic Protein(BMP). However, 6 months later (1 year post index operation), hypertrophic non-union along with breakage of the cephalon-medullary nail was found. A second revision operation was performed with removal of implant, exchange nailing and insertion of artificial bone substitute (BMP and hydroxyapatite bone substitute). Complete healing of the fracture was finally noted 6 months later (1.5 years after index operation).
The second case of non-union was found to have residual thigh pain upon serial post operative follow ups. Radiographs showed atrophic non-union over the lateral cortex fracture site. The patient was treated with dynamization of the nail with additional application of BMP at 9 months. There was clinical improvement in thigh pain afterwards, and the fracture was fully healed 14 months after the index operation.
Figure 9abc
Figure 9de
In regards to other complications, crucially no post operative neurovascular compromise of the lower limb related to cerclage wiring were noted. No cases of wound infection (superficial or deep) were noted, nor cerclage related complications such as cerclage loosening, breakage, skin impingement. 2 cases of return to theatre due to non-union for revision surgery were noted, and documented above.
Discussion
1. Appropriate union rates
The use of cerclage wiring has been a subjective of contention among orthopaedic surgeons for a prolonged period of time. Concerns regarding the periosteal stripping, disruption of the vasculature, violation of the soft tissue envelope and fracture haematoma have all been postulated, leading to worries about devitalisation of fracture fragments and hence impaired fracture healing. However, improvement in techniques and instruments, including use of minimally invasive percutaneous cerclage wiring has been suggested to reduce periosteal stripping and intra-operative soft tissue trauma.
Our study found a 94.3% union rate overall, with 33 cases going on to full union. The mean RUSH score was measured to be 21.5 at 6 months, indicating a robust radiographic healing rate. This reflects an appropriate rate and timing of union that is not hindered by the use of cerclage wiring, which is in line with current literature.
Kilinc et al performed a review of 52 cases of subtrochanteric fractures fixed with PFNA cephalon-medullary nail and cerclage wiring. Their study concluded that such treatment led to satisfactory fracture healing. They documented that all fractures went on to heal, but with 1 case of implant breakage and 2 cases of subsequent peri-implant fracture. Similarly, in Trikha et al’s series[ii], within their group of subtrochanteric fractures treated with cerclage, 1 case out of 21 was found to have delayed union, but went on to full union 6 months later after secondary dynamization of the nail. Codesido et al[iii] found no cases of non-union in their group of 30 patients treated with open cerclage wiring, but observed 1 case of implant cut out. Conversely, no lag screw or blade cut out was observed in our study. Fauconier et al[iv] assessed the effect on reoperation rates for patients treated with and without cerclage wiring. Among their series, there was no statistically significant difference in non-union between both groups. These studies would appear to concur with our results, which show a low non-union and reoperation rate.
Satisfactory union rates may suggest overstatement regarding the biological concerns of microvascular compromise. Application of circumferential cerclage wire should have low effect upon the microvasculature due to the radial orientation of periosteal vessels (rather than longitudinal)[v]. Thus, a single - or a few adequately spaced – cerclage wire is unlikely to cause complete strangulation. Furthermore, a cadaveric study by Apivatthakakul[vi] showed that percutaneous cerclage wiring did not result in disruption of the femoral endosteal blood supply, and that perforators perfusion and integrity were also maintained. This further gives credence that the previously feared impact upon fracture and bone fragment perfusion may be overstated, and that overall cerclage wiring in the subtrochanteric region offers no major hindrance to fracture healing.
2. Good quality of reduction and stability
The nature of subtrochanteric fractures frequently make reduction a large challenge. Provisional reduction with clamps or other reduction devices and techniques, such as percutaneous joysticking with Schanz pins, bone hooks, Hoffman retractors may be difficult to achieve and maintain a good reduction[vii]. We found that using cerclage wire as an adjunct to cephalon-medullary wiring helped in this aspect, and made the procedure easier, in particularly obtaining a good initial guidewire entry site. A commonly encountered problem with inadequate reduction is only being able to access an overly anterior or lateral entry point, thus predisposing to a varus, or apex anterior flexion deformity. Use of cerclage to optimise and maintain reduction before guidewire placement and nail entry can help to overcome this.
Furthermore, operative difficulty may be further increased by comminution or medial wall insufficiency. Application of cerclage wire often helped to restore the medial wall integrity, therefore restoring the buttress effect and preventing subsequent varus collapse[viii]. It was also helpful in restoration of large fragments and increasing the amount of bony contact after reduction. As a result of the increased bone contact and restoration of the anatomical alignment as much as possible, construct stability can be improved.
These findings are reflected in our results. In our series, 77.1% of reductions were good according to the Baumgartner criteria, while only 2.9% were poor. Crucially, the poor case also went on to non-union. While the relationship between quality of reduction and non-union status was not statistically significant, this may be limited due to the small number of the non-union group (2) leading to reduced statistical power. In practice, we also found in that case or poor reduction, the cerclage wire was improperly positioned and tightened, and finally ending up interposed at the fracture site in between fragments. It is likely that this further contributed to the lack of fracture healing.
Other studies, including a meta-analysis by Hoskins et al corroborates with our findings. They analysed 6 studies that compared the accuracy of fracture reduction between cerclage and non-cerclage groups. From their study, they concluded that fractures managed with cerclage wire augmentation resulted in statistically significant less fracture displacement, less fracture angulation and improved quality of fracture reduction compared to without use of cerclage[ix]. This difference was found to be statistically significant in favour of cerclage wiring. However, among these cases, a number were operated on using open reduction techniques and then supplemented with a cerclage wire, as opposed to our case series where wiring was done via a mini-open percutaneous technique. Karayiannis also noted an improvement in reduction in the subtrochanteric group operated on with cerclage wires[x]. However, in their intertrochanteric group, they found fewer cases with cerclage wire were deemed to be of good reduction, and there was also a higher rate of further surgery. This emphasises the need for proper indication such as usage in the subtrochanteric region for maximal benefit, as well as proper technique during surgery.
3. Absence of severe complications
In regards to complications, the most severe and devastating complication would be that of neurovascular injury. Neurovascular compromise can arise from inadvertent iatrogenic entrapment and ligation of common, deep or superficial femoral vessels or nerves during tightening of the cerclage wire. No such complication was found in our study. However, it has been documented in literature, with a case series by Devendra et al showing a 1.59% incidence of vascular injuries in cerclage usage for proximal femur shaft fractures[xi]. Technically, it is imperative to use an appropriately sized cerclage passer and pass both the anterior and posterior passers as close to the bone as possible. The local mobility of the deep femoral artery is reduced after traction is applied to the leg, while the superficial femoral nerve is brought closest to the femur during combined adduction and internal rotation[xii], thus increasing the risk of neurovascular involvement. This confirms the need for careful and meticulous surgical technique when applying the cerclage wire, while also considering the course of the vasculature in respect to the fracture site. Post operatively, vigilance is also required to assess the peripheral vascular status of the limb and avoid any postponement in detecting limb threatening complications.
4. Limitations
This study has a few limitations, including a relatively small sample size only compromised from single institution, and lack of a control group. Furthermore, three types of intramedullary nail were used without standardisation of exact nail diameter and length, which were subject both to patient factors as well as the operating surgeon’s preference. Modifications in regards to this, such as a larger case control study can rectify such limitations and confirm the positive effect of cerclage wiring upon fracture healing and reduction.
Conclusion
Our case series showed that cerclage wiring used as an adjunct treatment to intramedullary nailing of subtrochanteric fractures is a safe and effective technique with high union rates. This high union rate is also attributable to the majority of cases achieving good or satisfactory reduction, which also contributed to favourable healing outcomes. Combined with acceptable blood loss, operative times, and absence of significant complications in our series, adjunct cerclage wiring offers a balance between achieving high union rates, good reduction alignment while minimising disruption to biological healing potential and other complications. However, it remains imperative that the cerclage is applied in an appropriate and meticulous manner with correct technique; otherwise risk of non-union, mal-reduction or other complications such as vascular entrapment may arise.
APPENDIX
Appendix 1
Appendix 2
Appendix 3
