Tibial spine volume is smaller in ACL-injured athletes compared to healthy athletes

PURPOSE

The aim of this study was to investigate whether the whole tibial spine volume and femoral intercondylar notch volume are risk factors for anterior cruciate ligament (ACL) injury. The hypothesis was that the whole tibial spine volume and femoral notch volume would be smaller in athletes who sustained ACL injury than in athletes with no history of ACL injury.

METHODS

Computed tomography scans of both knees were acquired and three-dimensional bone models were created using Mimics to measure whole tibial spine volume and femoral notch volume. Tibial spine volume, femoral notch volume and each of these volumes normalised by tibial plateau area were compared between the ACL-injured and the ACL-intact group.

RESULTS

Fifty-one athletes undergoing unilateral anatomical ACL reconstruction (17 female, 34 male: average age 22.0 ± 7.5) and 19 healthy collegiate athletes with no previous knee injury (eight female, 11 male: average age 20.1 ± 1.3) were included in this study. The whole tibial spine volume in the ACL-injured group (2.1 ± 0.5 cm3) was 20.7% smaller than in the ACL-intact group (2.7 ± 0.7 cm3) (p = 0.005). No differences were observed between the femoral notch volume in the ACL-injured group (9.5 ± 2.1 cm3) and the ACL-intact group (8.7 ± 2.7 cm3) (n.s.).

CONCLUSIONS

The main finding of this study was that the whole tibial spine volume of the ACL-injured group was smaller than the ACL-intact group. A small tibial spine volume can be added to the list of anatomical risk factors that may predispose athletes to ACL injury.

LEVEL OF EVIDENCE

Level Ⅲ.

Arthroscopic fixation techniques for tibial eminence fractures in pediatric patients: a review

The introduction of new internal fixation devices and arthroscopic techniques has led to significant changes in the surgical treatment of tibial eminence fractures (TEFs) in children. In recent years, arthroscopic surgery has arisen as the gold standard for the treatment of TEFs. This popularity of arthroscopic techniques has reduced surgical complications and improved patient prognosis. In this paper, we investigate the current situation of the use of arthroscopic fixation techniques for pediatric TEFs. We searched the PubMed database using the terms "arthroscopic treatment and tibial eminence," "arthroscopic treatment and tibial spine," "tibial eminence avulsion", "tibial spine fracture", with no limit on the year of publication. From these articles, we reviewed the use of various arthroscopic TEFs fixation techniques reported in the current literature. Overall, we found that the choice of fixation method seems to have no effect on clinical outcomes or imaging results. However, if an easy, strong fixation that is less prone to epiphyseal damage is desired, as a junior practitioner, the anchor technique should be mastered first, whereas for senior practitioners, a variety of fixation techniques for TEFs should be mastered, including anchors, sutures, and screws, so that personalized fixation can be achieved with the least amount of trauma, operative time, and complications. Higher quality studies are needed in the future to provide Useful evidence to determine the optimal fixation technique in terms of clinical outcomes, function, and complications.

Reliability of the Tibial Spine Versus ACL Stump in Assisting Tibial Tunnel Positioning During ACL Reconstruction: Analysis Based on 3-Dimensional Computed Tomography Modeling

Background

Several techniques have been used by surgeons for anatomic tibial tunnel placement in anterior cruciate ligament (ACL) reconstruction, including the ACL stump positioning (ASP) technique and the tibial spine positioning (TSP) technique.

Purpose/Hypothesis

The purpose of this study was to evaluate whether bony landmarks (medial and lateral tibial spine [MLTS]) can be a reliable reference for improving the accuracy of tibial tunnel placement in anatomic single-bundle ACL reconstruction compared with the ACL stump. It was hypothesized that the MLTS would not be a reliable bony landmark for tibial tunnel placement.

Study Design

Cohort study; Level of evidence, 3.

Methods

The 3-dimensional computed tomography images of 111 patients who underwent ACL reconstruction between 2020 and 2021 were included in this study. For tibial tunnel placement, the ASP technique was used in 49 patients, and the TSP technique was used in 62 patients. The 3-dimensional computed tomography images were reconstructed to enable measurements of the locations of the MLTS and tunnel center based on a grid method. Statistical analysis was conducted to compare the MLTS location and tibial tunnel position as well as the accuracy (mean distance of each actual location from the anatomic center) and precision (standard deviation of the accuracy, indicating the reproducibility of the tunnel position) of the tunnel position between the ASP and TSP groups.

Results

Significant differences were observed between the ASP and TSP groups in terms of the tibial tunnel position on the mediolateral axis (46.7% ± 2.0% vs 45.9% ± 2.2%, respectively; P = .034), while no significant differences were found in terms of the accuracy (4.1% vs 4.6%, respectively; P = .259) or precision (2.1% vs 2.1%, respectively; P = .259) of tibial tunnel positioning between the 2 groups.

Conclusion

In anatomic single-bundle ACL reconstruction, the use of the MLTS for tibial tunnel placement achieved comparable accuracy and precision compared with the use of ACL remnants, supporting its role as a reliable bony landmark in tibial tunnel positioning.

Screws or Sutures? A Pediatric Cadaveric Study of Tibial Spine Fracture Repairs

BACKGROUND

Tibial spine fractures are common in the pediatric population because of the biomechanical properties of children's subchondral epiphyseal bone. Most studies in porcine or adult human bone suggest that suture fixation performs better than screw fixation, but these tissues may be poor surrogates for pediatric bone. No previous study has evaluated fixation methods in human pediatric knees.

PURPOSE

To quantify the biomechanical properties of 2-screw and 2-suture repair of tibial spine fracture in human pediatric knees.

STUDY DESIGN

Controlled laboratory study.

METHODS

Cadaveric specimens were randomly assigned to either 2-screw or 2-suture fixation. A standardized Meyers-Mckeever type 3 tibial spine fracture was induced. Screw-fixation fractures were reduced with two 4.0-mm cannulated screws and washers. Suture-fixation fractures were reduced by passing 2 No. 2 FiberWire sutures through the fracture fragment and the base of the anterior cruciate ligament. Sutures were secured through bony tunnels over a 1-cm tibial cortical bridge. Each specimen was mounted at 30° of flexion. A cyclic loading protocol was applied to each specimen, followed by a load-to-failure test. Outcome measures were ultimate failure load, stiffness, and fixation elongation.

RESULTS

Twelve matched pediatric cadaveric knees were tested. Repair groups had identical mean (8.3 years) and median (8.5 years) ages and an identical number of samples of each laterality. Ultimate failure load did not significantly differ between screw (mean ± SD, 143.52 ± 41.9 7 N) and suture (135.35 ± 47.94 N) fixations (P = .760). Screws demonstrated increased stiffness and decreased elongation, although neither result was statistically significant at the .05 level (21.79 vs 13.83 N/mm and 5.02 vs 8.46 mm; P = .076 and P = .069, respectively).

CONCLUSION

Screw fixation and suture fixation of tibial spine fractures in human pediatric tissue were biomechanically comparable.

CLINICAL RELEVANCE

Suture fixations are not biomechanically superior to screw fixations in pediatric bone. Pediatric bone fails at lower loads, and in different modes, compared with adult cadaveric bone and porcine bone. Further investigation into optimal repair is warranted, including techniques that may reduce suture pullout and "cheese-wiring" through softer pediatric bone. This study provides new biomechanical data regarding the properties of different fixation types in pediatric tibial spine fractures to inform clinical management of these injuries.

Tibial Spine Fracture in an Adolescent Male After Minor Injury: A Case Report

CASE PRESENTATION

A 13-year-old male presented with right knee pain and swelling from a basketball injury. The right knee exam demonstrated minimal swelling, decreased range of motion secondary to pain, and generalized tenderness. A radiograph of the right knee revealed a tibial spine fracture.

DISCUSSION

Tibial spine fractures are avulsion fractures of the spine of the tibia at the insertion site of the anterior cruciate ligament. The incidence of avulsion fractures is higher in adolescents because the region of the apophyseal growth plate between the soft-tissue attachment site and the body of the bone is weaker in that age group. Tibial spine avulsion fractures are relatively uncommon and occur annually in approximately three per 100,000 children.

Does Insurance Status Affect Treatment of Children With Tibial Spine Fractures?

BACKGROUND

Previous studies have reported disparities in orthopaedic care resulting from demographic factors, including insurance status. However, the effect of insurance on pediatric tibial spine fractures (TSFs), an uncommon but significant injury, is unknown.

PURPOSE

To assess the effect of insurance status on the evaluation and treatment of TSFs in children and adolescents.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

We performed a retrospective cohort study of TSFs treated at 10 institutions between 2000 and 2019. Demographic data were collected, as was information regarding pre-, intra-, and postoperative treatment, with attention to delays in management and differences in care. Surgical and nonsurgical fractures were included, but a separate analysis of surgical patients was performed. Univariate analysis was followed by purposeful entry multivariate regression to adjust for confounding factors.

RESULTS

Data were collected on 434 patients (mean ± SD age, 11.7 ± 3.0 years) of which 61.1% had private (commercial) insurance. Magnetic resonance imaging (MRI) was obtained at similar rates for children with public and private insurance (41.4% vs 41.9%, respectively; P≥ .999). However, multivariate analysis revealed that those with MRI performed ≥21 days after injury were 5.3 times more likely to have public insurance (95% CI, 1.3-21.7; P = .02). Of the 434 patients included, 365 required surgery. Similar to the overall cohort, those in the surgical subgroup with MRI ≥21 days from injury were 4.8 times more likely to have public insurance (95% CI, 1.2-19.6; P = .03). Children who underwent surgery ≥21 days after injury were 2.5 times more likely to have public insurance (95% CI, 1.1-6.1; P = .04). However, there were no differences in the nature of the surgery or findings at surgery. Those who were publicly insured were 4.1 times more likely to be immobilized in a cast rather than a brace postoperatively (95% CI, 2.3-7.4; P < .001).

CONCLUSION

Children with public insurance and a TSF were more likely to experience delays with MRI and surgical treatment than those with private insurance. However, there were no differences in the nature of the surgery or findings at surgery. Additionally, patients with public insurance were more likely to undergo postoperative casting rather than bracing.

Arthroscopic Repair in Tibial Spine Avulsion Fractures Using Polyethylene Terephthalate Suture: Good to Excellent Results in Pediatric Patients

Background: The objective of the arthroscopic treatment in tibial spine avulsion fractures (TSAF) is to achieve firm reduction and strong internal fixation while still having the patient undergo a minimally invasive procedure. Material and methods: The study was performed on 12 young patients with avulsion fracture of the anterior tibial spine. All 12 patients had type 3 Modified Meyers and McKeever fractures. The injury mechanism was direct anterior to posterior trauma in full leg length hyperextension with sport trauma reported in all cases. The physical examination revealed decreased range of motion, extension deficit, and pain during walking. Radiology, MRI, and CT pathologic findings described complete fracture of the anterior tibial spine with no clear signs of callus formation at the time of examination. All patients underwent arthroscopic suture surgical treatment. The Tegner, the Lysholm, and the International Knee Documentation Committee (IKDC) scores were used to evaluate subjective outcomes at three and six months after the surgery. Radiographs were used to assess callus formation and healing status of the fracture. Results: The mean IKDC score was 33.4 ± 23.3 (p = 0.032) preoperatively and 84.2 ± 14.3 at final follow-up (p = 0.0032, CI = 95%). The mean Tegner score improved from 3.8 ± 1.1 pre-operatively to 6.7 ± 2.2 at six months follow-up (p = 0.0231, CI = 95%). The Lysholm score differed significantly at baseline compared to final follow-up (53.7 ± 17.3 vs. 87.7 ± 9.9; p = 0.0066, CI = 95%). In all cases (n = 12), the radiographs taken after six months revealed the healing of the fracture in the anatomic position without secondary displacement. No functional knee instability was detected at the end of the study. Conclusions: The study provides preliminary promising results regarding fracture healing, knee stability, and functional subjective scores. Patient selection was a major factor of success prediction for this technique.

Arthroscopic Reduction and Fixation by Cerclage Wire Loop for Tibial Spine Avulsion in Adults: Short-term Results

Background:

Several arthroscopic techniques for the treatment of avulsion tibial spine fractures have been described in the literature.

Purpose:

To evaluate the outcomes of the arthroscopically assisted stainless steel wiring technique in the treatment of avulsed tibial spine in adults.

Study Design:

Case series; Level of evidence, 4.

Methods:

This retrospective study involved 28 patients (28 knees), 16 to 42 years of age, with tibial spine avulsion fracture that was treated using arthroscopic reduction and cerclage wire fixation by a single surgeon between March 2015 and August 2018. The degrees of avulsion in these patients were type II (n = 12), type III (n = 10), and type IV fractures (n = 6). Clinical assessment included International Knee Documentation Committee (IKDC) objective score (which noted swelling), range of knee movement, Tegner activity scale, Lachman test, and pivot-shift test compared with the normal opposite knee.

Results:

The mean follow-up period was 24.1 months (range, 18-30 months). The mean IKDC score was 93.7 (range, 88.5-98.9); the IKDC score was normal in 22 patients and nearly normal in 6 patients. The Lachman test was grade 1 in 25 patients and grade 2 in 3 patients, whereas the pivot-shift test was grade 0 in 26 patients and grade 1 in 2 patients. All patients achieved their preinjury Tegner activity levels. Radiological assessment showed healing in all patients within a mean of 12 weeks after surgery.

Conclusion:

The outcomes of all patients were satisfactory; fixation by cerclage wiring permitted reduction of tibial spine fragment anatomically to its fracture bed, provided stable fixation in displaced tibial spine avulsion, and allowed for early rehabilitation and weightbearing because of stable fixation.

Suture Versus Screw Fixation of Tibial Spine Fractures in Children and Adolescents: A Comparative Study

Background

Tibial spine fractures involve an avulsion injury of the anterior cruciate ligament (ACL) at the intercondylar eminence, typically in children and adolescents. Displaced fractures are commonly treated with either suture or screw fixation.

Purpose

To investigate differences in various outcomes between patients treated with arthroscopic suture versus screw fixation for tibial spine avulsion fractures in one of the largest patient cohorts in the literature.

Study Design

Cohort study; Level of evidence, 3.

Methods

A search of medical records was performed with the goal of identifying all type 2 and type 3 tibial spine avulsion fractures surgically treated between 2000 and 2014 at a pediatric hospital. All patients had a minimum of 12 months clinical follow-up, suture or screw fixation only, and no major concomitant injury.

Results

There were 68 knees in 67 patients meeting criteria for analysis. There were no differences with regard to postsurgical arthrofibrosis (P = .59), ACL reconstruction (P = .44), meniscal procedures (P = .85), instability (P = .49), range of motion (P = .51), return to sport (P >.999), or time to return to sport (P = .11). Elevation of the repaired fragment on postoperative imaging was significantly greater in the suture group (5.4 vs 3.5 mm; P = .005). Postoperative fragment elevation did not influence surgical outcomes. The screw fixation group had more reoperations (13 vs 23; P = .03), a larger number of reoperations for implant removal (3 vs 22; P < .001), and nearly 3 times the odds of undergoing reoperation compared with suture patients (odds ratio, 2.9; P = .03).

Conclusion

Clinical outcomes between suture and screw fixation were largely equivalent in our patients. Postoperative fragment elevation does not influence surgical outcomes. Consideration should be given for the greater likelihood of needing a second operation, planned or unplanned, after screw fixation.

Knee Extension Does Not Reliably Reduce Acute Type II Tibial Spine Fractures: MRI Evaluation of Displacement During Extension Versus Resting Flexion

Background:

Type II tibial spine avulsion (TSA) fractures have traditionally been managed by first attempting to achieve closed reduction with extension and immobilization, with surgical indications reserved for those who fail to reduce within 3 mm. However, the frequency with which appropriate reduction can be achieved is largely unknown.

Purpose:

To evaluate changes in displacement of type II TSA fractures by comparing magnetic resonance imaging (MRI) scans obtained with the knee in flexion and in extension.

Study Design:

Case series; Level of evidence, 4.

Methods:

Ten patients with type II TSA fractures were identified. Fracture displacement was measured using 3 images for each patient: (1) initial lateral view radiography, (2) sagittal-plane MRI of the knee in resting flexion, and (3) sagittal-plane MRI of the knee in passive extension. Maximum displacement of the bony fragment was measured in the 2 MRI studies for all patients, and the corresponding change in displacement was calculated. Displacement in flexion was compared with displacement in extension using a paired-sample t test. Statistical significance was set at P < .05.

Results:

The displacement distance of the bony fragment was reduced by a mean of 0.97 mm on MRI when the knee was in extension compared with flexion in patients with type II TSA fractures (P = .02). Mean displacement with extension was 6.14 mm, with no fractures reduced below 4 mm. The largest reduction observed was 2.80 mm. The displacement distance increased in 2 knees with extension. The intermeniscal ligament (IML) was entrapped in 4 of 10 patients; however, the amount of reduction achieved did not differ based on the presence of IML entrapment (P = .85).

Conclusion:

While the amount of tibial spine displacement warranting surgical treatment can be debated, the study findings suggest that knee extension is not reliable in obtaining adequate closed reduction for type II TSA fractures. Management decisions may need to be based on the initial displacement distance of the fracture, with a lower threshold for operative treatment than previously recognized.

Delayed Anterior Cruciate Ligament Reconstruction in Young Patients With Previous Anterior Tibial Spine Fractures

BACKGROUND

Avulsion fractures of the anterior tibial spine in young athletes are injuries similar to anterior cruciate ligament (ACL) injuries in adults. Sparse data exist on the association between anterior tibial spine fractures (ATSFs) and later ligamentous laxity or injuries leading to ACL reconstruction.

PURPOSE

To better delineate the incidence of delayed instability or ACL ruptures requiring delayed ACL reconstruction in young patients with prior fractures of the tibial eminence.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

We identified 101 patients between January 1993 and January 2012 who sustained an ATSF and who met inclusion criteria for this study. All patients had been followed for at least 2 years after the initial injury and were included for analysis after completion of a questionnaire via direct contact, mail, and/or telephone. If patients underwent further surgical intervention and/or underwent later ACL reconstruction, clinical records and operative reports pertaining to these secondary interventions were obtained and reviewed. Differences between categorical variables were assessed using the Fisher exact test. The association between time to revision ACL surgery and fracture type was assessed by Kaplan-Meier plots. The association between need for revision ACL surgery and age, sex, and mechanism of surgery was assessed using logistic regression.

RESULTS

Nineteen percent of all patients evaluated underwent delayed ACL reconstruction after a previous tibial spine fracture on the ipsilateral side. While there were a higher proportion of ACL reconstructions in type II fractures, there was not a statistically significant difference in the number of patients within each fracture group who went on to undergo later surgery (P = .29). Further, there was not a significant association between fracture type, sex, or mechanism of injury as it related to the progression to later ACL reconstruction. However, there was a significant association between age at the time of injury and progression to later ACL reconstruction (P = .02). For every year increase in age at the time of injury, the odds of going on to undergo delayed ACL reconstruction were greater by a factor of 1.3 (95% CI, 1.1-1.6).

CONCLUSION

Although an ATSF is a relatively rare injury, our cohort of patients suggests that a subset of young patients with all types of tibial spine fractures will require later ACL reconstruction. There is a need to counsel patients that a delayed ACL rupture is a potential risk after an ATSF, especially as children approach skeletal maturity. Further patient follow-up and prospective studies are required.

Arthroscopic treatment of tibial eminence fracture: a systematic review of different fixation methods

INTRODUCTION

Arthroscopy procedures are the gold standard for the management of tibial spine avulsion. This review evaluates and compares different arthroscopic treatment options for tibial spine fractures.

SOURCE OF DATA

PubMed, Medline, Ovid, Google Scholar and Embase databases were systematically searched with no limit regarding the year of publication.

AREAS OF AGREEMENT

An arthroscopic approach compared with arthrotomy reduces complications such as soft-tissue lesions, post-operative pain and length of hospitalization.

AREAS OF CONTROVERSY

The use of suture techniques, compared to cannulated screw technique, avoids a second surgery for removal of the screws, but requires longer immobilization and partial weight bearing.

GROWING POINTS

Clinical outcomes and radiographic results do not seem to differ in relation to the chosen method of fixation.

AREAS TIMELY FOR DEVELOPING RESEARCH

Further studies are needed to produce clear guidelines to define the best choice in terms of clinical outcomes, function and complications.

Treatment and Management Outcomes of Tibial Eminence Fractures in Pediatric Patients: A Systematic Review

BACKGROUND

Tibial eminence fractures are rare but occur more frequently in children and adolescents. There are a variety of methods to surgically treat these fractures, but surgeons disagree about the optimal method of reduction and fixation.

HYPOTHESES

Regarding clinical results and complications after treatment in children and adolescent patients with tibial eminence fractures, the authors hypothesize that (1) there is no difference between reduction and fixation with screws versus sutures, (2) there is no difference in arthroscopic versus open reduction and fixation, and (3) outcomes are better in patients with minimally displaced (types I and II) versus completely displaced (types III and IV) fractures.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic review of the literature was performed studying the treatment of tibial eminence fractures in children and adolescents to determine clinical results, functional outcomes, and complications. A meta-analytic technique on observational studies was used to compare outcomes when sufficient data were available.

RESULTS

The review identified 26 articles with extractable clinical results and data on complications: 1 level 3 article and 25 level 4 articles. Ten of 580 tibial eminence fractures identified in the literature had nonunion, with 60% of nonunions occurring in type III fractures treated by nonoperative modalities. Appreciable healing was noted for both open and arthroscopic fixation techniques as well as patients treated by screw or suture fixation. Laxity (P < .001) and loss of range of motion (P = .009) occurred significantly less after the treatment of minimally displaced fractures (types I and II).

CONCLUSION

The level of evidence supporting various treatments of tibial eminence fractures in children and adolescents is low. There is insufficient evidence to conclude the superiority of open versus arthroscopic fixation or screw versus suture fixation techniques. Nonoperative treatment of completely displaced tibial eminence fractures results in higher rates of nonunion. Type III and IV fractures heal with greater laxity and greater loss of range of motion after treatment. Higher level studies are necessary to determine the optimal method of fixation for tibial eminence fractures.

Tibial eminence fractures in the paediatric population: a systematic review

INTRODUCTION

We present a systematic review of the literature for the management of tibial eminence fractures in the paediatric population. Our aims were to assess modalities of injury, treatment options available and their associated complications.

MATERIALS AND METHODS

We found 740 relevant citations in the English literature up to 1 October 2012, of which 36 full text articles met our inclusion criteria.

RESULTS

Our results show that skiing, sports and motor vehicle accidents are increasingly common modes of injury, in addition to the commonly described fall off of a bicycle. Most studies advocate non-operative management for type I Meyer's and McKeever's fractures and reduction and internal fixation for type II and III fractures. Better long-term results have been reported with arthroscopic surgery compared to open surgery. There is no consensus as to which type of fixation is best suited for tibial eminence fractures; methods available include excision of the bony fragment, K-wire, screw and, absorbable suture fixation, and more recently, suture anchor and meniscal arrow. The main complications reported include arthrofibrosis, non-union, mal-union, pain and severe laxity. Early post-operative range of motion exercises have been shown to reduce the incidence of arthrofibrosis.

CONCLUSION

As all papers report results from small case series, Level I studies are required to produce more definitive evidence for the management of paediatric tibial eminence fractures.

Biomechanical evaluation of physeal-sparing fixation methods in tibial eminence fractures

BACKGROUND

Tibial eminence fractures occur most commonly in skeletally immature children. Several techniques using physeal-sparing fracture fixation have been described, but their structural properties have not been evaluated.

PURPOSE

To determine the strength and resistance to displacement of physeal-sparing techniques used to fix tibial eminence fractures.

STUDY DESIGN

Controlled laboratory study.

METHODS

Skeletally immature porcine knees were randomized into 4 treatment groups: (1) ultra-high molecular weight polyethylene suture-suture button (UHMWPE/SB), (2) suture anchor, (3) polydioxanone suture-suture button (PDS/SB), and (4) screw fixation. A prospective analysis of bone mineral density using dual-energy x-ray absorptiometry was performed on all specimens. Fracture fragments were created in a standardized manner and measured for size comparison. After fracture fixation, biomechanical testing was performed with cyclical and load-to-failure protocols by loading the tibia with an anterior shear force.

RESULTS

In load-to-failure testing, screw fixation had a significantly lower median peak failure load (186.4 N; lower quartile [LQ], 158.4 N; upper quartile [UQ], 232.6 N) than did UHMWPE/SB (465.8 N; LQ, 397.8 N; UQ, 527.8 N), suture anchors (440.5 N; LQ, 323.0 N; UQ, 562.3 N), and PDS/SB (404.3 N; LQ, 385.9 N; UQ, 415.6 N). UHMWPE/SB demonstrated a significantly higher median yield load (465.8 N; LQ, 397.8 N; UQ, 527.8 N) than did PDS/SB (306.7 N; LQ, 271.4, N; UQ, 405.7 N) and screw fixation (179.0 N; LQ, 120.2 N; UQ, 232.5 N). During cyclical testing, screw fixation demonstrated significantly lower percentage survival of specimens (0%) compared with the other groups (UHMWPE/SB, 100%; suture anchor, 78%; PDS/SB, 78%). After 1000 cycles of loading, PDS/SB fixation had significantly more median creep (6.76 mm; LQ, 6.34 mm; UQ, 8.28 mm) than did UHMWPE/SB (4.43 mm; LQ, 3.80 mm; UQ, 4.73 mm) and suture anchor fixation (3.06 mm; LQ, 2.59 mm; UQ, 4.28 mm). The lowest median stiffness was observed in the PDS/SB group (48.6 N/mm; LQ, 45.3 N/mm; UQ, 54.2 N/mm). UHMWPE/SB fixation demonstrated a significantly higher median peak failure load after cyclic testing (469.0 N; LQ, 380.6 N; UQ, 507.2 N) than did PDS/SB (237.7 N; LQ, 197.3 N; UQ, 298.3 N) and screw fixation (132.4 N; LQ, 123.7 N; UQ, 180.9 N). Suture anchor fixation had significantly more variance, as demonstrated by width of interquartile range, in peak failure load, yield load, and creep than did other techniques.

CONCLUSION

Physeal-sparing fixation of tibial eminence fractures with UHMWPE suture-suture button is biomechanically superior to both PDS suture-suture button and a single screw at the time of surgery and provides more consistent fixation than do suture anchors.

CLINICAL RELEVANCE

Suture anchors provide inconsistent fixation for tibial eminence fractures.