Practice variation in common fracture presentations: a survey of orthopaedic surgeons

Background

Practice variation may indicate a lack of clear evidence to guide treatment. This study aims to quantify practice variation for common orthopaedic fractures, and to explore possible predictors of the variation.

Materials and methods

A nationwide electronic survey of Australian orthopaedic surgeons was performed. Five common fractures (ankle, scaphoid, distal radius, neck of humerus, and clavicle) were presented. Data on management preferences and surgeon background were gathered. Potential predictors of operative (vs. non-operative) treatment were explored.

Results

358 of 760 (47%) surgeons responded. For the ankle, undisplaced scaphoid, distal radius, neck of humerus and clavicle fractures, operative treatment was chosen in 40%, 44%, 77%, 26% and 38%, respectively. Operative treatment was significantly more likely to be chosen by more junior surgeons, and by surgeons specialising in the affected area (i.e., shoulder surgeons for clavicle and neck of humerus fractures, and hand surgeons for scaphoid and distal radius fractures).

Conclusions

Variations exist in the management of common fractures. Variation may represent legitimate improvisation for varying clinical scenarios, but it may reflect clinician bias, which in turn, may contribute to varying standards of care for the management of common conditions.     

Alpine ski and snowboarding traumatic injuries: incidence, injury patterns, and risk factors for 10 years

Background

Alpine skiing and snowboarding are popular winter sports in Canada. Every year participation in these activities results in traumatic injury. The purpose of this study was to identify the incidence and injury patterns, as well as risk factors associated with ski and snowboarding injuries.

Methods

A comprehensive 10-year retrospective review of Alpine ski and snowboarding injuries from 1996 to 2006 was conducted. The Alberta Trauma Registry was used as the primary source of data.

Results

A total of 196 patients (56.6% skiers, 43.4% snowboarders) were identified as having major traumatic injuries (Injury Severity Score, ≥12). Forty-three patients required intensive care unit support. The majority of injuries were related to falls and collisions with natural objects. Head injuries were most common, followed by chest, spinal, and extremity trauma. Seventy-nine patients required emergency surgery.

Conclusions

Skiing and snowboarding represent activities with high potential for traumatic injury. Safety initiatives should be developed to target this population.     

Uso de terapia con presión negativa en heridas con fístulas entéricas

Objective

Negative pressure therapy (VAC, vacuum assisted closure) is a method used still in our country. It consists of a system of aspirating a wound by means of a piece of foam and a few adhesive films. It allows the treatment of complex wounds, included (although this is still controversial) those with intestinal fistulas. We present 3 cases of treatment with VAC in this situation and a review of the published literature.

Patients and method

We have treated 10 patients, since VAC therapy was introduced into our centre of which 3 of whom had a fistula in the bed of the surgical wound. We describe the clinical information of the patients and the therapy that followed in each of the cases.

Results

Significant local clinical improvement of the disease, with control of the symptoms, was achieved in all 3 cases. We were able to re-operate to close the fistula in one of the patients, with subsequent good progression of the wound. In the other two cases it gave them a better quality of life although both died due to the overall complexity of their situation.

Conclusions

VAC therapy, although controversial in the treatment of intestinal fistulas, can help to improve the local situation of the wounds, the comfort of the patients and their general situation.     

Health and cost consequences of surgical versus conservative treatment for a comminuted proximal humeral fracture in elderly patients

Objective

This study aims to evaluate the costs and health outcome for surgical and conservative treatment of displaced proximal humeral fractures.

Design

This study is a randomised controlled trial.

Participants

This study included 50 patients aged 60 or older admitted to hospital with a severely displaced three- or four-part fracture.

Interventions

The patients were treated surgically with an angular stable interlocking implant (25 patients) or conservative treatment (25 patients).

Main outcome measure

The outcomes measured included quality-adjusted life years (QALYs) and societal costs.

Results

At 12 months’ follow-up, the mean difference in the number of QALYs was 0.027 (95% confidence interval (CI) = −0.025, 0.078) while the mean difference in total health-care costs was €597 in favour of surgery (95% CI = −5291, 3777).

Conclusion

There was no significant difference in QALYs or costs between surgical and conservative treatment of severe displaced proximal humeral fractures.     

Laparoscopic excision of choledochal cyst and Roux-en-Y hepaticojejunostomy in symptomatic neonates

Purpose

Choledochal cysts require surgical excision, preferably before the onset of cholangitis. Recently, it has become feasible to accomplish the excision laparoscopically in adults and older children. Yet, whether laparoscopic excision of choledochal cyst can be performed safely in symptomatic neonates with choledochal cyst is unclear. We herewith reviewed our experience of laparoscopic excision of choledochal cysts in neonates.

Methods

We managed 9 neonates with choledochal cysts between April 2003 and February 2007. The choledochal cysts were excised laparoscopically. The Roux-en-Y hepaticojejunostomy was fashioned extracorporeally by exteriorizing the jejunum through the extended umbilical port site. End-to-side anastomosis between the common hepatic duct stump and Roux loop was carried out intracorporeally. The patients were followed up for an average of 26 months.

Results

The patients presented with jaundice, pale stool, and deranged liver function tests. The diagnosis was confirmed with ultrasonography postnatally. The median operation time was 3.6 hours. There was no operative complication and no conversion. The blood loss was minimal. The recovery was uneventful, and the median hospital stay was 6 days. The liver function tests normalized 3 to 16 weeks postoperatively. No complication was detected at the follow-up visits.

Conclusions

Our preliminary results show that laparoscopic excision of choledochal cyst and Roux-en-Y hepaticojejunostomy in neonates is both feasible and safe. It curtails further complication of the cysts and reverses the derangement of liver function. In addition, the laparoscopic approach minimizes surgical trauma.     

Pediatric thyroidectomy: a collaborative surgical approach

Introduction

We have developed a collaborative approach to pediatric thyroid surgery, with operations performed at a children's hospital by a pediatric surgeon and an endocrine surgeon. We hypothesize that this strategy minimizes specialist-specific limitations and optimizes care of children with surgical thyroid disease.

Methods

Data from all partial and total thyroidectomies performed by the pediatric-endocrine surgery team at a tertiary children's hospital between 1995 and 2009 were collected and analyzed retrospectively. Statistical analyses were performed with IBM SPSS software (SPSS, Chicago, IL).

Results

Thirty-five children met the inclusion criteria (69% female; median age, 13 years; median follow-up, 1119 days). The indications for operation were thyroid nodule (71%), genetic abnormality with predisposition to thyroid malignancy (17%), multinodular goiter (5.7%), Grave disease (2.9%), and Hashimoto thyroiditis (2.9%). Sixteen children (46%) underwent thyroid lobectomy, and 19 children (54%) underwent total thyroidectomy. Median length of stay was 1 day (1 day after lobectomy vs 2 days after total thyroidectomy, P < .0001). There were 4 cases of transient hypocalcemia after total thyroidectomy, but there were no nerve injuries or other in-hospital complications in either group (overall complication rate, 11%).

Conclusions

For pediatric thyroidectomy and thyroid lobectomy, collaboration of high-volume endocrine and pediatric surgeons as well as pediatric endocrinologists at a dedicated pediatric medical center provides optimal surgical outcomes.     

Predictive indicators for bowel injury in pediatric patients who present with a positive seat belt sign after motor vehicle collision

Purpose

Abdominal wall bruising (AWB) is a frequent finding in children wearing seat belts involved in motor vehicle collision (MVC) and is highly suspicious but not indicative of intestinal injury. The aim of this study was to find objective clinical and radiologic predictors for the need of an abdominal exploration in these children.

Materials and Methods

A retrospective chart review of children admitted from 1998 and 2008 with AWB after MVC was conducted. Demographics, vital signs, physical examinations, radiologic investigations, associated injuries, management, and outcome were extracted. Univariate and multivariate statistical analyses were done.

Results

Fifty-three children with a median age of 9 years (range, 3-16 years) were included. Forty-four patients (83%) had abdominal pain on arrival, and 25 (47%) had free intraabdominal fluid on ultrasound/scan. Intraabdominal injuries were noted in 29 patients (55%), and the most common were mesenteric or bowel injuries (25%), splenic injuries (13%), and hepatic injuries (8%). Ten patients (19%) needed therapeutic laparotomy, and all were victims from collision involving 2 moving vehicles, had abdominal pain, free intraabdominal fluid, and tachycardia. Five patients (50%) operated on had lumbar fracture compared to only 4 patients (9%) in the nonoperative group. Pulse rate higher than 120 (P = .048), lumbar fracture (P = .008), and free intraabdominal fluid (P ≤ .001) were significant predictors for intestinal perforation. Overall survival was 98% with 1 death because of head trauma.

Conclusion

Intraabdominal injuries in children with AWB after MVC are frequent. Associated lumbar fracture, the presence of free intraabdominal fluid, and pulse rate higher than 120 are significant predictors of intestinal injuries. An abdominal exploration should be considered in these patients.     

Sentinel lymph node biopsy in patients with multicentric/multifocal breast cancer: low false-negative rate and lack of axillary recurrence

Background

Accuracy of sentinel lymph node biopsy (SLNB) and rate of axillary recurrence in multicentric/multifocal (MC/MF) breast cancer are reported.

Methods

From 1999 to 2006, 93 patients with MC/MF breast cancer underwent SLNB; 41 underwent axillary lymph node dissection regardless of SLN pathology (group 1), and 52 underwent axillary lymph node dissection only if an SLN was positive (group 2). Patient demographics, SLN techniques, and pathology were recorded.

Results

There were no differences between the 2 groups with respect to patient age; tumor size, grade, stage, and histology; or method of SLN detection. The incidence of axillary metastasis was greater in group 1 patients (68%) compared with group 2 patients (12%) (P < .01). In group 1, the sensitivity and specificity of SLNB were 93% and 100%, respectively, with a false-negative rate of 7%. None of the 52 patients in group 2 experienced axillary recurrence (median follow-up 4.8 years).

Conclusions

The accuracy of SLNB in MC/MF breast cancer is comparable with that observed in unifocal breast cancer. Despite a lower rate of SLN positivity in patients undergoing SLNB only, axillary recurrence was not observed.     

Iliosacral screw insertion using CT-3D-fluoroscopy matching navigation

Background

Percutaneous iliosacral screw insertion requires substantial experience and detailed anatomical knowledge to find the proper entry point and trajectory even with the use of a navigation system. Our hypothesis was that three-dimensional (3D) fluoroscopic navigation combined with a preoperative computed tomography (CT)-based plan could enable surgeons to perform safe and reliable iliosacral screw insertion. The purpose of the current study is two-fold: (1) to demonstrate the navigation accuracy for sacral fractures and sacroiliac dislocations on widely displaced cadaveric pelves; and (2) to report the technical and clinical aspects of percutaneous iliosacral screw insertion using the CT-3D-fluoroscopy matching navigation system.

Methods

We simulated three types of posterior pelvic ring disruptions with vertical displacements of 0, 1, 2 and 3 cm using cadaveric pelvic rings. A total of six fiducial markers were fixed to the anterior surface of the sacrum. Target registration error over the sacrum was assessed with the fluoroscopic imaging centre on the second sacral vertebral body. Six patients with pelvic ring fractures underwent percutaneous iliosacral screw placement using the CT-3D-fluoroscopy matching navigation. Three pelvic ring fractures were classified as type B2 and three were classified as type C1 according to the AO-OTA classification. Iliosacral screws for the S1 and S2 vertebra were inserted.

Results

The mean target registration error over the sacrum was 1.2 mm (0.5–1.9 mm) in the experimental study. Fracture type and amount of vertical displacement did not affect the target registration error. All 12 screws were positioned correctly in the clinical series. There were no postoperative complications including nerve palsy. The mean deviation between the planned and the inserted screw position was 2.5 mm at the screw entry point, 1.8 mm at the area around the nerve root tunnels and 2.2 mm at the tip of the screw.

Conclusion

The CT-3D-fluoroscopy matching navigation system was accurate and robust regardless of pelvic ring fracture type and fragment displacement. Percutaneous iliosacral screw insertion with the navigation system is clinically feasible.     

Cochlear implantations in young children with cochlear nerve deficiency diagnosed by MRI

Objective

To investigate postoperative outcomes after cochlear implantation in young children with cochlear nerve deficiency and compare the results with those of cochlear implantation in patients with normal cochlear nerve.

Study Design

Historical cohort study.

Setting

Tertiary referral center.

Subjects and Methods

Six children under the age of 36 months with cochlear nerve deficiency, as determined by magnetic resonance imaging (MRI), received cochlear implantation between July 2006 and March 2008. Fifteen children under the age of 36 months with normal cochlear nerve in the implanted ear underwent cochlear implantation during the same period and were selected as the control group. Medical records, imaging studies, and speech evaluations were reviewed.

Results

Our study group scored lower in the Infant-Toddler Meaningful Auditory Integration Scale compared to the control group. Our study group produced categories of auditory performance scores not less than 4 except for one patient. Speech intelligibility rating scores in the control group gradually increased after cochlear implantation, but for the study group, the score remained zero 12 months after the implantation. In open-set one-syllable tests, five patients with cochlear nerve deficiency showed no response at the latest follow-up, whereas patient 6 began to show delayed improvement after 18 months. The results of the open-set two-syllable test were similar to those of the open-set one-syllable test.

Conclusion

Young children with nonvisualized cochlear nerve on MRI showed worse outcomes compared to the children with normal cochlear nerve. Cochlear nerve deficiency on MRI is a marker of very poor outcome with cochlear implantations.     

Ventral petrous meningiomas: unique tumors

Introduction

This study aims to analyze our experience with petrous meningiomas (PM), testing the hypothesis that these tumors have different histologic subtypes and operative outcome depending on the site of origin in reference to the internal auditory canal (IAC).

Methods

Fifty-eight patients with PM were reviewed retrospectively. Tumors were classified as posterior (PPM; n = 29), superior (SPM; n = 8), and ventral petrous (VPM; n = 19), in reference to the IAC. Two patients had multiple meningiomas arising from different parts of the petrous bone. Petroclival, clival, and jugular tubercle meningiomas were excluded. All patients were operated through a suboccipital retrosigmoid approach. Clinical presentation, tumor size, involvement of IAC, extent of resection, outcome, and tumor histology were analyzed.

Results

Simpson grade I and II resection was achieved in 84.5%: 96.6% in PPM, 100% in SPM, and 57.9% in VPM. Fibrous histology accounted for 69% in PPM, 62% in SPM, and only 10.5% in VPM, whereas meningothelial histology was seen 27.6%, 25%, and 68.4%, respectively. Postoperative hearing loss was the most frequent operative complication, and was seen in 31.6% of VPM, as compared to none in PPM or SPM.

Conclusions

Ventral petrous meningiomas are clearly different tumors in their histology and operative outcome. The predominance of meningothelial histology in this location may imply a different tumorigenesis as compared to other PM. Ventral petrous meningiomas should be viewed as a distinct group of tumors.     

Preoperative lornoxicam for pain prevention after tonsillectomy in adults

Study Objective

To evaluate the efficacy of preoperative lornoxicam on postoperative pain management following tonsillectomy.

Design

Prospective, randomized, double-blinded, placebo-controlled study.

Setting

King Fahd University Hospital.

Patients

40 adult, ASA physical status I and II patients scheduled for tonsillectomy.

Interventions

Patients were randomly allocated to two groups to receive either intravenous (IV) lornoxicam 16 mg (Group L) or saline as control (Group C) preoperatively. Anesthesia was induced using IV fentanyl and propofol, while endotracheal intubation was facilitated with rocuronium, and maintenance was accomplished using nitrous oxide and sevoflurane.

Measurements

Pain scores at rest and on swallowing, intraoperative bleeding, interval until first request for rescue diclofenac suppository, and total diclofenac dose given in the first 12 and 24 hours postoperatively were recorded. The frequency of postoperative complications including bleeding, hypoxia, nausea and vomiting also were observed.

Main Results

Pain scores at rest were significantly lower in Group L than Group C at all observation times. Similarly, pain scores on swallowing were lower in Group L during the first 4 postoperative hours. The maximum verbal pain scale (VPS) in the control group was 7 (5.75 - 8 median, interquartile range) and in the lornoxicam group, it was 4 (4 - 5 median, interquartile range) (P < 0.001). The total diclofenac dose during the immediate postoperative 12 hours was significantly lower in Group L than Group C (65 ± 24 mg vs. 20 ± 25 mg, respectively; P < 0.001). No significant differences were noted for intraoperative bleeding. The frequency of postoperative nausea and vomiting was similar in both groups.

Conclusion

Preoperative 16 mg lornoxicam was effective for immediate postoperative pain relief after tonsillectomy in adults.     

Navigation in femoral-shaft fractures--from lab tests to clinical routine

Introduction

This study evaluates the use of a navigation system (BrainLAB, Feldkirchen, Germany) to intra-operatively check for correct length, axis and rotation in intramedullary nailing of femoral-shaft fractures in an experimental setting and in clinical routine.

Materials and methods

We tested the navigation system in two experimental settings before introducing it into clinical routine. In the first experiment, 10 osteotomised model femora were fixed with intramedullary nails by using a navigation system. The goal was a locking fixation in predefined values for length and rotation.In the second experiment, eight examiners assessed values for rotation and length of one femur 10 times to examine the accuracy and reproducibility of that determination.Following this, we navigated 40 femoral nailing procedures in our department. Preoperatively, we assessed values of femur geometry on the contralateral side in a computed tomography (CT) scan and reproduced these values intra-operatively on the fractured side, guided by the navigation system. During the intervention, we recorded the length of the procedure steps and the fluoroscopy time.We verified the intra-operative values achieved with the navigation system in a postoperative CT scan and documented differences in rotation and length.After the assessment, we analysed the data for different findings on femur geometry, fluoroscopy time and procedure duration.

Results

The experimental evaluation showed a range of ±5° for anteversion differences and ±2.3 mm for length differences. We estimated this accuracy as sufficient to use the system in clinical routine. The navigation system was used for 40 fracture fixations. All our criteria for restoring femoral geometry could be achieved by navigation guidance in these procedures.Setting up the system took on average 33 ± 11.5 min. An additional fluoroscopy time of 36 ± 22 s was needed to acquire the reference X-rays and to verify pin placement.The differences between anteversion values assessed in intra-operative planning steps on the navigation system and values assessed with a postoperative CT were on average 5.4 ± 3.5°, whilst femur length differed on average by 4 ± 4 mm.

Discussion

Many authors judge intra-operative control of anteversion in femoral-shaft fracture fixation as problematic.Neither our experimental navigation assessment nor our clinical navigated evaluation showed relevant anteversion differences to a postoperative CT assessment of femur geometry. After initial training, guidance by a navigation system achieves consistent results in a clinical situation.

Conclusions

The use of a navigation system to align axis, length and rotation led to a secure way of avoiding any relevant malalignment in complex femur-shaft fractures whilst exposing patients to an acceptable amount of additional procedure sequences.Malalignment can be avoided by using a navigation system in the operative treatment of femoral-shaft fractures and may be integrated into clinical routine in specialised centres.     

The role of abiraterone acetate in the management of prostate cancer: a critical analysis of the literature

Context

The development of agents targeting androgen signalling holds promise for men with castration-resistant prostate cancer (CRPC).

Objective

The emerging role of abiraterone acetate (AA), a novel, orally administered androgen synthesis inhibitor, is critically analysed.

Evidence acquisition

Data were acquired from critically important original research published in peer-reviewed literature or presented at conferences conducted by the American Society of Clinical Oncology and the European Society of Medical Oncology.

Evidence synthesis

The major findings are addressed in an evidence-based, objective, and balanced fashion.

Conclusions

AA specifically inhibits CYP17 and substantially reduces serum androgen levels without inducing significant adrenal insufficiency. A phase 3 trial reported a significant extension of survival in metastatic CRPC with AA plus prednisone compared to prednisone alone following docetaxel. The primary toxicity of mineralocorticoid excess is manageable. The addition of low-dose corticosteroids to AA may be necessary for controlling symptoms of mineralocorticoid excess.     

The percutaneous antegrade scaphoid fracture fixation—A safe method?

Introduction

The object of this study was to assess the risk of injury to tendons, nerves and vessels in percutaneous antegrade scaphoid fracture fixation.

Methods

Forty cadaveric forearms were used in this study. A guide wire for cannulated headless compression screws was inserted percutaneously in each scaphoid according to established surgical technique.

Results

No nerve or vessel injuries were observed. Tendons however were injured in 5 out of the 40 specimens. This included the extensor pollicis longus tendon in two specimens, the extensor carpi radialis tendon in two specimens and the extensor digitorum tendon in one specimen.

Conclusions

Soft tissue injuries may be avoided by extending the skin incision and performing blunt dissection down to guide wire and screw entry point. In this manner, dorsal antegrade fixation of scaphoid fractures by using cannulated headless compression screws can be considered to be a safe and reliable technique for fixation of scaphoid fractures.     

Analgesic efficacy of ultrasound-guided regional anesthesia: a meta-analysis

Study Objective

To determine if the use of ultrasound guidance (vs non-ultrasound techniques) improves the success rate of nerve blocks.

Design

Meta-analysis of randomized controlled trials (RCTs) in the published literature.

Setting

University medical center.

Measurements

16 RCTs of patients undergoing elective surgical procedures were studied. Patients underwent ultrasound-guided or non-ultrasound techniques (nerve stimulation, surface landmark) for peripheral nerve blocks. Success rates were measured.

Main Results

Ultrasound guidance (vs all non-ultrasound techniques) was associated with a significant increase in the success rate of nerve blocks [relative risk (RR) = 1.11 (95% confidence interval [CI]: 1.06 to 1.17, P < 0.0001]). When compared with nerve stimulator techniques only, ultrasound guidance was still associated with an increase in the success rate (RR = 1.11 [95% CI: 1.05 to 1.17, P = 0.0001]). For specific blocks, ultrasound guidance (vs all non-ultrasound) was associated with a significant increase in successful brachial plexus (all) nerve blocks (RR = 1.11 [95% CI: 1.05 to 1.20, P = 0.0001]), sciatic popliteal nerve block (RR = 1.22 [95% CI: 1.08 to 1.39, P = 0.002]) and brachial plexus axillary nerve block (RR = 1.13 [95% CI: 1.00 to 1.26, P = 0.05]) but not brachial plexus infraclavicular nerve block (RR = 1.25 [95% CI: 0.88 to 1.76, P = 0.22]).

Conclusions

Ultrasound-guided peripheral nerve block is associated with an increased overall success rate when compared with nerve stimulation or other methods. Ultrasound-guided techniques also increase the success rate of some specific blocks.     

Risk factors and outcome of early recurrence after resection of small hepatocellular carcinomas

Background

This study aimed to clarify risk factors for early recurrence and examine the subsequent outcome in patients undergoing potentially R0 resection of small hepatocellular carcinomas (HCCs) (≤2 cm in greatest dimension).

Methods

Eighty-nine patients were divided into 2 groups as follows: 26 patients suffering from recurrence within 2 years of surgery (early recurrence group) and 63 patients who were disease-free for at least 2 years (disease-free 2Y group).

Results

Only 7 of 63 patients (11%) from the group that was disease-free for at least 2 years died during the 5-year period after surgery, whereas 13 of 26 patients (50%) from the early recurrence group died. Multivariate analysis showed that the preoperative maximum removal rate of technetium-99m-diethylenetriamine pentaacetic acid-galactosyl human serum albumin and microscopic vascular invasion were independent predictors of the early recurrence of small HCC.

Conclusions

Early recurrence of small HCC is the leading cause of death within 5 years after R0 resection. The preoperative hepatic functional reserve influences early recurrence, even in patients with small tumors.     

Intravenous landiolol, a novel β(1)-adrenergic blocker, reduces the minimum alveolar concentration of sevoflurane in women

Study Objective

To investigate the effect of intravenous (IV) landiolol, a novel β₁-adrenergic blocker, on the minimum alveolar concentration (MAC) of sevoflurane in adult women.

Design

Prospective, randomized study.

Setting

University hospital.

Patients

42 ASA physical status 1 and 2 women, aged 24-57 years, who were scheduled to undergo elective abdominal surgery.

Interventions

Anesthesia was induced in all patients by vital capacity rapid inhalation induction of sevoflurane. In the landiolol group, administration of landiolol began when patients took a vital-capacity breath: 0.125 mg/kg/min for one minute and then 0.04 mg/kg/min. Normal saline was administered in the control group.

Measurements

MAC was determined by a technique adapted from the conventional up-down method.

Main Results

The MAC of sevoflurane was 2.2% ± 0.2% in the control group and 1.7% ± 0.2% in the landiolol group, a statistically significant difference (P = 0.0005).

Conclusions

IV landiolol reduces the MAC of sevoflurane in women by approximately 20%.     

Spinal intraoperative three-dimensional navigation: correlation between clinical and absolute engineering accuracy

Background Context

Spinal intraoperative computer-assisted navigation (CAN) may guide pedicle screw placement. Computer-assisted navigation techniques have been reported to reduce pedicle screw breach rates across all spinal levels. However, definitions of screw breach vary widely across studies, if reported at all. The absolute quantitative error of spinal navigation systems is theoretically a more precise and generalizable metric of navigation accuracy. It has also been computed variably and reported in less than a quarter of clinical studies of CAN-guided pedicle screw accuracy.