Cement-in-cement femoral component revision in the multiply revised total hip arthroplasty: results with a minimum follow-up of five years

Application of Piezosurgery in Revision Surgery through Posterior Approach for Infection after Percutaneous Vertebral Augmentation: Technique Note with Case Series

OBJECTIVES

Pyogenic spondylitis after vertebral augmentation (PSVA) is a severe complication and even threatens the life of patients. How to deal with infectious bone cement is a big problem for surgeons. The application of piezosurgery has advantages in removal the infectious bone cement in limb bone and spinal laminectomy, but it is rarely used in PSVA. So, the present study aimed to introduce the application of piezosurgery in revision surgery for PSVA and report the preliminary radiological and clinical results.

METHODS

The data of nine patients with PSVA who had undergone revision surgery were retrospectively reviewed between May 2017 and January 2023 in our hospital. The technique of removal of infectious bone cement and lesion by piezosurgery and the reconstruction of the spinal stability were described, and the operation time and intraoperative blood loss were recorded. Postoperatively, radiographs and computed tomography scans were reviewed to evaluate the condition of bone cement removal, control of infection, and bone fusion. Oswestry disability index (ODI) and visual analog scale (VAS) were assessed pre- and postoperatively, and clinical outcomes were assessed using Odom's criteria.

RESULTS

All patients achieved satisfactory tainted bone cement cleaning and restoration of spinal alignment. The surgical time was 258.8 ± 63.2 (160-360) min, and the intraoperative blood loss was 613.3 ± 223.8 (300-900) mL. The VAS score decreased from 7.0 (6-8) points preoperatively to 2.4 (1-4) points postoperatively. The ODI index decreased from 71% (65%-80%) preoperatively to 20% (10%-30%) postoperatively. The patient's VAS and NDI scores after operation were significantly improved compared with those before surgery (p ≤ 0.05). Odom's outcomes were good for all patients in the last follow-up, and all patients reported satisfactory results.

CONCLUSIONS

Piezosurgery can effectively remove large blocks of infectious bone cement through a posterior approach while avoiding nerve and spinal cord damage. We cautiously suggest that a one-stage posterior approach using piezosurgery is an alternative option for surgical treatment of PSVA.

Mixed manufacturer dual mobility bearing and the Exeter V40 Stem: is it safe? Short-term results in primary and revision hip replacement

The aim is to review clinical and radiological outcomes for all cases of primary and revision THA, combining a cemented stem (Exeter V40) with a dual mobility component from a different manufacturer (SERF Novae), to evaluate whether concerns regarding mixing components from different manufacturers are justified. We identified 72 hip replacements performed between May 2010 and December 2015 using the SERF Novae dual mobility cup with an Exeter V40 stem, the majority of which were cemented (90%) and revisions (58%). Patients were evaluated clinically and radiologically at a minimum of two years. There were five (6.9%) dislocations; three (4.2%) requiring revision - one of which was an intra-prosthetic disarticulation and two infections. No cases were lost to follow-up and 49 surviving cases were reviewed at a mean of 4.0 (range 1.8-8.1) years following surgery. Pain and functional outcome scores all improved. There were no radiological failures and no revisions for aseptic loosening of stem or cup. The combination of Exeter cemented stem with a dual mobility bearing from a different manufacturer results in acceptable short-term outcomes in terms of hip stability, revision rates and patient-reported measures.

Clinical and Functional Outcomes of the Exeter V40 Short Stem in Primary and Revision Arthroplasty: Does the Indication Affect Outcomes in the Short Term?

Purpose

A variety of short Exeter stems designed specifically for use in performance of total hip arthroplasty (THA) in primary and revision settings have recently been introduced. Some have been used 'off label' for hip reconstruction. The aim of this study is to report clinical and radiological results from the Exeter V40 125 mm stem in performance of primary THA and revision THA.

Materials and Methods

This study had a retrospective design. Insertion of 58 (24 primary, 34 revision) Exeter V40 125 mm stems was performed between 2015 and 2017. The minimum follow-up period was two years. Assessment of the Oxford hip score (OHS), EuroQol-5 Dimension (EQ-5D), and radiological follow-up was performed at one and two years.

Results

In the primary group, the preoperative, mean OHS was 13.29. The mean OHS was 32.86 and 23.39 at one-year and two-year post-surgery, respectively. The mean EQ-5D-3L scores were at 0.14, 0.59, and 0.35, preoperatively, at one-year follow-up and two-year follow-up, respectively. In the revision group, the mean preoperative OHS was 19.41. The mean OHS was 30.55 and 26.05 at one-year and two-year post-surgery, respectively. The mean EQ-5D-3L scores were 0.33, 0.61, and 0.48 preoperatively, at one-year follow-up and two-year follow-up, respectively. No progressive or new radiolucent lines were observed around any stem at the time of the final follow-up in all patients in both groups.

Conclusion

Encouraging results regarding use of Exeter V40 125 mm stems have been reported up to two years following surgery in primary and revision THA settings.

Open Reduction and Internal Fixation and Cement-In-Cement Revision for Selected Vancouver B Proximal Femur Periprosthetic Fractures

The incidence of periprosthetic proximal femoral fractures is increasing with the increase in arthroplasty being performed as well as aging populations. We describe an open reduction and internal fixation and cement-in-cement technique utilizing a well-fixed cement mantle. The advantages of this allow for a shorter operative time, reduction in risk of iatrogenic femoral fractures, and reduction in blood loss. This was a retrospective study reviewing 20 patients that underwent this technique for periprosthetic fractures. Thirty percent (n = 6) of patients underwent subsequent surgery. We had a 95% (n = 19) union rate with 1 case refracturing through the old fracture. This technique can allow for shorter operative times and a lower physiological insult in reducible periprosthetic proximal femur fractures with a stable cement mantle.

Ultrasonic bone cement removal efficiency in total joint arthroplasty revision: A computer tomographic-based cadaver study

Polymethylmethacrylate (PMMA) removal during septic total joint arthroplasty revision is associated with a high fracture and perforation risk. Ultrasonic cement removal is considered a bone-preserving technique. Currently, there is still a lack of sound data on efficacy as it is difficult to detect smaller residues with reasonable technical effort. However, incomplete removal is associated with the risk of biofilm coverage of the residue. Therefore, the study aimed to investigate the efficiency of ultrasonic-based PMMA removal in a human cadaver model. The femoral components of a total hip and a total knee prosthesis were implanted in two cadaver femoral canals by 3rd generation cement fixation technique. Implants were then removed. Cement mantle extraction was performed with the OSCAR-3-System ultrasonic system (Orthofix®). Quantitative analysis of cement residues was carried out with dual-energy and microcomputer tomography. With a 20 µm resolution, in vitro microcomputer tomography visualized tiniest PMMA residues. For clinical use, dual-energy computer tomography tissue decomposition with 0.75 mm resolution is suitable. With ultrasound, more than 99% of PMMA was removed. Seven hundred thirty-four residues with a mean volume of 0.40 ± 4.95 mm³ were identified with only 4 exceeding 1 cm in length in at least one axis. Ultrasonic cement removal of PMMA was almost complete and can therefore be considered a highly effective technique. For the first time, PMMA residues in the sub-millimetre range were detected by computer tomography. Clinical implications of the small remaining PMMA fraction on the eradication rate of periprosthetic joint infection warrants further investigations.

Multi-centre study of cement-in-cement and in-cement femoral revision total hip arthroplasty using polished, stainless steel stems

BACKGROUND

Exposure of the acetabular component during revision total hip arthroplasty is often difficult and stems are often difficult to remove. Polished and tapered cemented stems are easily removed and can be easily reconstructed by either cement-in-cement or in-cement technique. This study was a retrospective review of the medium-term outcomes of revision total hip arthroplasty conducted with the Exeter stem fixed by cement-in-cement or in-cement method in four institutions.

METHODS

This study included hips (n = 103) reconstructed by cement-in-cement or in-cement technique on the femoral side during revision total hip arthroplasty in four institutions between 2003 and 2015. The mean age at surgery was 71.1 years (range, 43-86 years), and the mean follow-up period was 5.6 years (range, 0-13 years).

RESULTS

Revision arthroplasty was required for acetabular component complications in 69 hips, for dislocation in 25, for infection in eight, and for stem fracture in one hip. Re-revision was required in 10 hips for: infection (n = 6), acetabular component complications (n = 3), and dislocation (n = 1). No radiographic loosening, cement fractures, or osteolysis of the femoral components were observed. Ten-year survival rate was 99% with the endpoint of femoral revision surgery, and 100% with the endpoint of femoral aseptic loosening.

CONCLUSIONS

The medium-term outcomes of revision total hip arthroplasty on the femoral side conducted using the cement-in-cement or in-cement technique were favourable, with no cases of aseptic loosening. As long as the bone-cement interface remains robust, there is no need to remove all the cement, and the cement-in-cement or in-cement technique should be used for reconstruction.

Comparable outcomes of in-cement revision and uncemented modular stem revision for Vancouver B2 periprosthetic femoral fracture at 5 years

INTRODUCTION

Periprosthetic femoral fractures (PFF) are detrimental for patients. Vancouver B2 fractures about a cemented stem can be revised to a longer uncemented stem or using an in-cement revision, if the cement mantle is adequate. There are reports documenting the success of both techniques. The aim of this single centre study was to perform a direct comparison of these two procedures.

MATERIALS AND METHODS

A retrospective study of consecutive Vancouver B2 PFFs around a cemented stem during 16 years was performed. All study cases were treated either using an in-cement revision or with an uncemented stem revision. Preoperatively, the groups were compared based upon age, gender, ASA, BMI, and Charlson comorbidity score. The outcome measures were surgical time, complications, in-hospital stay, revisions, 1-year readmission rate, and survivorship.

RESULTS

After a median of 3.5 years, there were 70 patients in the uncemented and 31 in the in-cement group. There was no difference in any of the preoperative variables. Surgical time was shorter for in-cement revisions by a mean of 45 min (p < 0.001). There was no difference in in-hospital stay, surgical complications or readmissions. Implant survival at 5 years was 93.5% for the in-cement and 94.4% for the uncemented revision (p = 0.946). Patient survivorship at 5 years was 62.5% for the in-cement and 69.8% for the uncemented group (p = 0.094).

CONCLUSIONS

This study demonstrates that in-cement revision is a valid treatment option for Vancouver B2 fractures, comparable to uncemented stem revision, if certain criteria are met. There was no difference in revision rate, patient survivorship, complications, readmissions or in-hospital stay.

Cement-in-cement technique of the femoral component in aseptic total hip arthroplasty revision: A systematic review of the contemporary literature

Background

Clinical outcomes of cemented femoral stems revisions using the cement-in-cement technique in aseptic conditions after total hip arthroplasty have been widely described.

Methods

The US National Library of Medicine (PubMed/MEDLINE), EMBASE, and the Cochrane Database of Systematic Reviews were queried.

Results

Twelve articles were included (620 revision THA). Revision rate for complications related to the femoral side was 1.4% at mid-term follow-up (5.4 years). Periprosthetic femoral fracture rate was 1.1%, aseptic loosening of the femoral component 0.3%.

Conclusions

Cement-in-cement revision technique of the femoral component is associated with a high mid-term success rates (98.6%) and is potentially less challenging than other revision techniques.

The cement-bone bond is weaker than cement-cement bond in cement-in-cement revision arthroplasty. A comparative biomechanical study

This study compares the strength of the native bone-cement bond and the old-new cement bond under cyclic loading, using third generation cementing technique, rasping and contamination of the surface of the old cement with biological tissue. The possible advantages of additional drilling of the cement surface is also taken into account. Femoral heads from 21 patients who underwent a total hip arthroplasty performed for hip arthritis were used to prepare bone-cement samples. The following groups of samples were prepared. A bone—cement sample and a composite sample of a 6 weeks old cement part attached to new cement were tested 24 hours after preparation to avoid bone decay. Additionally, a uniform cement sample was prepared as control (6 weeks polymerization time) and 2 groups of cement-cement samples with and without anchoring drill hole on its surface, where the old cement polymerized for 6 weeks before preparing composite samples and then another 6 weeks after preparation. The uniaxial cyclic tension-compression tests were carried out using the Zwick-Roell Z020 testing machine. The uniform cement sample had the highest ultimate force of all specimens (n = 15; R_m = 3149 N). The composite cement sample (n = 15; R_m = 902 N) had higher ultimate force as the bone-cement sample (n = 31; R_m = 284 N; p <0.001). There were no significant differences between composite samples with 24 hours (n = 15; R_m = 902 N) and 6 weeks polymerization periods (n = 22; R_m = 890 N; p = 0.93). The composite cement samples with drill hole (n = 16; R_m = 607 N) were weaker than those without it (n = 22; R_m = 890 N; p < 0.001). This study shows that the bond between the old and new cement was stronger than the bond between cement and bone. This suggests that it is better to leave the cement that is not loosened from the bone and perform cement in cement revision, than compromising bone stock by removal of the old cement with the resulting weaker cement-bone interface. The results support performing cement-in-cement revision arthroplasty The drill holes in the old cement mantle decrease cement binding strength and are not recommended in this type of surgery.

Conversion from a failed proximal femoral nail anti-rotation to a cemented or uncemented total hip arthroplasty device: a retrospective review of 198 hips with previous intertrochanteric femur fractures

Background

At present, it is unclear which device (uncemented or cemented total hip arthroplasty [UTA or CTA, respectively]) is more suitable for the conversion of a failed proximal femoral nail anti-rotation (PFNA). The aim of this review was to assess the outcomes of failed PFNAs converted to a UTA or CTA device in elderly individuals with intertrochanteric femoral fractures (IFFs).

Methods

Two hundred fifty-eight elderly individuals (258 hips) with IFFs who underwent a conversion to a UTA or CTA device following failed PFNAs during 2007–2017 were retrospectively identified from the China Southern Medical Centre (CSMC) database. The primary endpoint was the Harris Hip Score (HHS); secondary endpoint was the key orthopaedic complication rate.

Results

The median follow-up was 65 months (60–69 months). Significant distinctions were observed (87.26 ± 16.62 for UTA vs. 89.32 ± 16.08 for CTA, p = 0.021; 86.61 ± 12.24 for symptomatic UTA vs. 88.68 ± 13.30 for symptomatic CTA, p = 0.026). A significant difference in the overall key orthopaedic complication rate was detected (40.8% [40/98] vs. 19.0% [19/100], p = 0.001). Apparent distinctions were detected in terms of the rate of revision, loosening, and periprosthetic fracture (11.2% for UTA vs 3.0% for CTA, p = 0.025; 13.2% for UTA vs 5.0% for CTA, p = 0.043; 10.2% for UTA vs 3.0% for CTA, p = 0.041, respectively).

Conclusion

For elderly individuals with IFFs who suffered a failed PFNA, CTA devices may have a noteworthy advantage in regard to the revision rate and the rate of key orthopaedic complications compared with UTA devices, and CTA revision should be performed as soon as possible, regardless of whether these individuals have symptoms.

The cement-in-cement technique is a reliable option in hip arthroplasty revision surgery: a systematic review

INTRODUCTION

The cement-in-cement technique for revision hip arthroplasty has many potential advantages and has recently gained widespread interest but still lacks evidence to support it. Our aim was to examine the surgical and patient-reported outcomes after cement-in-cement revision hip arthroplasty.

MATERIALS AND METHODS

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed and EMBASE databases were searched up to February 2019 for original studies reporting the outcomes of revision hip arthroplasty surgeries using the cement-in-cement technique. The methodological quality was assessed using the methodological index for non-randomized studies scale.

RESULTS

Sixteen non-comparative studies met the eligibility criteria, comprising 1899 hips in 1856 patients (72.2 mean age, 37% male), with a mean follow-up of 7.2 years. Most studies reported only primary revisions and focused on the stem component. Intraoperative complications such as femoral or acetabular fractures (5.3%) were low and easily manageable with no relevant sequelae, as were dislocation rates (2.8% of uncomplicated events and 1.6% of cases requiring re-revision). Failure (considered if there was aseptic loosening of the cement-in-cement revised component, 2%), re-revision (9.3%), implant survival and late complication rates were favourable. Functional patient-reported outcomes showed an overall improvement above the minimal clinically important difference at final follow-up.

CONCLUSION

The cement-in-cement technique is a viable option for hip arthroplasty revision surgery with low intraoperative and late complication rates, dislocations and immediate post-operative morbidity, resulting in good functional patient-reported outcomes and favourable medium-term implant survival.

Promising results of revision total hip arthroplasty using a hexagonal, modular, tapered stem in cases of aseptic loosening

Background

Modular stems are widely used in revision total hip arthroplasty (THA) with aseptic loosening being a common reason for revision. Despite the good results reported on the use of modular stem designs, there are only few studies focusing on aseptic revisions and few studies on a hexagonal stem design. The goal of this study is to determine stem survival, clinical and functional outcome along with possible risk factors for implant failure in aseptic revision THA.

Methods

We retrospectively identified 53 patients with aseptic THA revision using a modular hexagonal stem with a minimum follow-up of two years. Femoral bone loss, radiographic and clinical outcomes as well as function measured using the Harris Hip Score (HHS) was assessed. Patients’ previous medical history was analyzed for comorbidities and the body mass index. Stem survival was calculated using the Kaplan-Meier method. Possible risk factors for implant failure were analyzed using the log-rank test. The median age at revision was 69 (IQR 62–73) with a median follow up of 74 months.

Results

Implant survival rates amounted to 90.4% at 3 and 5 years. The median HHS improved by 47 points (34 (IQR 22–47) vs 81 (IQR 59–90) p<0.001). There was a reduced implant survival after 5 years when the revision stem was used following a previous cemented stem (83.4% vs 100%, p = 0.04).

Conclusion

A modular, hexagonal stem can be successfully used in aseptic revision THA with remarkable functional results and excellent survivorship. Revision of a cemented stem using this implant might result in reduced survival which must be considered when planning treatment.

Cement-in-cement revision with the Exeter Short Revision Stem: A review of 50 consecutive hips

Revision of a well-fixed cemented femoral stem is technically challenging. The Exeter Short Revision Stem (SRS) was developed to facilitate cement-in-cement revision mitigating some of these challenges. We present the short to mid-term results of 50 cement-in-cement revisions performed with this implant. A retrospective review of all cement-in-cement revision with the Exeter SRS, at our institution, over a seven-year period between 2007 and 2014 was conducted. Records were assessed for radiological and clinical component loosening at greater than 12 months follow-up and for revision and complications at all time points. An Oxford Hip Score (OHS) and Numeric Rating Scale (NRS) for groin and thigh pain at rest and initial mobilisation were obtained. 50 implants in 46 patients were identified. Radiographic and clinical follow-up was available for 42 and 38 implants respectively at greater than 12 months. Mean radiographic follow-up was 5.1 years and clinical 4.9 years. There was no radiographic or clinical evidence of loosening. 3 revisions were performed, one for each of recurrent dislocation, infection and stem breakage. Median OHS was 39 (IQR 12) and mean NRS for groin pain at rest and initial mobilisation was 1.7 and 1.7 respectively and NRS for thigh pain at rest and initial mobilisation was 1.3 and 1.6 respectively with mean follow-up of 6.9 years. The Exeter SRS provides a viable option for cement-in-cement stem revision, with low revision, complication and loosening rates and good patient reported outcomes at short to mid-term follow up.

Outcomes of Cement in Cement Revision, in Revision Total Hip Arthroplasty

BACKGROUND

The cement-in-cement femoral revision technique involves removing a femoral component from a well-fixed femoral cement mantle and cementing a new stem into the original mantle. This technique, when carried out for the correct indications, is fast, relatively inexpensive and carries a reduced short-term risk for the patient compared with conventional way of removing well-fixed cement.

AIM

To analyze the effectiveness of cement in cement revision of the femoral stem while performing a revision Total Hip Arthroplasty (THA).

METHODS

We analyzed a consecutive series of 79 patients who underwent a cement in cement revision THA between June-2015 to June-2018. All the patients were retrospectively analysed for operative time, complications, clinical and radiological outcomes.

RESULTS

Average age was 76 years (49-86). The mean follow-up was 16.2 months (12-45). The average operative time was 184.6 (90-290) minutes. Most common indication was cup loosening in 28 patients (42.4%), dislocation in 14 patients (21.2%) and stem loosening in 12 patients (18.2%) Nine patients (11%) had one or more complications. Pre-operatively, 10 patients (13%) had lucency at the cement bone interface. Recent review has shown that 8 of these patients' radiographs have remained unchanged, and in 2 of them there is a slight progression of lucency. Common post op clinical complaintswere persistent pain and abductor weakness. Five (6.3%) patients required a re-revision. Most of the patients had a good or satisfactory outcome.No stems showed radiological loosening.

CONCLUSION

The cement-in-cement technique for revision of the femoral component gave promising results and had the advantages of speed, less blood or bone stock loss, less risk of femoral perforation or fracture, decreased financial costs and reduced post op morbidity.

Ultrasonic cement removal in cement-in-cement revision total hip arthroplasty: What is the effect on the final cement-in-cement bond?

Objectives

Previous studies have evidenced cement-in-cement techniques as reliable in revision arthroplasty. Commonly, the original cement mantle is reshaped, aiding accurate placement of the new stem. Ultrasonic devices selectively remove cement, preserve host bone, and have lower cortical perforation rates than other techniques. As far as the authors are aware, the impact of ultrasonic devices on final cement-in-cement bonds has not been investigated. This study assessed the impact of cement removal using the Orthosonics System for Cemented Arthroplasty Revision (OSCAR; Orthosonics) on final cement-in-cement bonds.

Methods

A total of 24 specimens were manufactured by pouring cement (Simplex P Bone Cement; Stryker) into stainless steel moulds, with a central rod polished to Stryker Exeter V40 specifications. After cement curing, the rods were removed and eight specimens were allocated to each of three internal surface preparation groups: 1) burr; 2) OSCAR; and 3) no treatment. Internal holes were recemented, and each specimen was cut into 5 mm discs. Shear testing of discs was completed by a technician blinded to the original grouping, recording ultimate shear strengths. Scanning electron microscopy (SEM) was completed, inspecting surfaces of shear-tested specimens.

Results

The mean shear strength for OSCAR-prepared specimens (33.6 MPa) was significantly lower than for the control (46.3 MPa) and burr (45.8 MPa) groups (p < 0.001; one-way analysis of variance (ANOVA) with Tukey’s post hoc analysis). There was no significant difference in shear strengths between control and burr groups (p = 0.57). Scanning electron microscopy of OSCAR specimens revealed evidence of porosity undiscovered in previous studies.

Conclusion

Results show that the cement removal technique impacts on final cement-in-cement bonds. This in vitro study demonstrates significantly weaker bonds when using OSCAR prior to recementation into an old cement mantle compared with cement prepared with a burr or no treatment. This infers that care must be taken in surgical decision-making regarding cement removal techniques used during cement-in-cement revision arthroplasty, suggesting that the risks and benefits of ultrasonic cement removal need consideration.

Cite this article: A. Liddle, M. Webb, N. Clement, S. Green, J. Liddle, M. German, J. Holland. Ultrasonic cement removal in cement-in-cement revision total hip arthroplasty: What is the effect on the final cement-in-cement bond? Bone Joint Res 2019;8:246–252. DOI: 10.1302/2046-3758.86.BJR-2018-0313.R1.

Technical Note: Pedicle Cement Augmentation with Proximal Screw Toggle and Loosening

Background

Cement augmentation is a technique used to increase the stability and purchase of pedicle screws in poor quality bone. Various methods can be applied for cement delivery, such as cement injection before screw placement and the use of fenestrated screws. However, potential problems can arise with the use of cement augmentation.

Case Presentation

A 66‐year‐old man with a lower trunk deformity, severe kyphosis, and sagittal imbalance following fusion (L_2‐5), with minimal comorbidities, was referred to our unit 9 months after surgery. Pain and progressive kyphosis were investigated clinically and radiographically with computed tomography (CT) scans to assess the status of the hardware and fusion. CT imaging revealed that cement was present only at the distal tip of the fenestrated screws at the L4 vertebral level. A non‐union was present along with loosening and a halo around the body of the pedicle screws, and there was evidence of pullout of inferior screws.

Conclusion

Single‐level cement augmentation of pedicle screw in a posterior construct and distal tip cement augmentation of the screw results in a fixed pivot point. Micromotion in cranio‐caudal loading during flexion and extension may result in screw toggling with the single‐level cement‐augmented tip as a fulcrum. This may cause screw loosening, which can lead to pullout and loss of construct stability. The halo around the screw suggests bone loss and/or a fibrous tissue interface, which further complicates revision surgery. Stress shielding and polymethylmethacrylate cement present additional difficulties.

The findings of this technical note question the risks and benefits of cement‐augmented fenestrated pedicle screw fixation for spinal fusion. Although incidences of such cases are uncommon, surgeons should perform this technique with caution. Accurate restoration of lumbar lordosis during index procedures is important to minimize the risk of construct failure.