Somatic diversification of chicken immunoglobulin light chains by point mutations. Proc Natl Acad Sci U S A. 1990;87:3072-3076. [PMID: 2109325 DOI: 10.2214/ajr.10.6095]

Diagnostic Performance of Multi-Direction Adjusted Multi-Planar Reconstruction with Helical CT for Evaluating Continuity of the Anterior Cruciate Ligament

RATIONALE AND OBJECTIVES

To analyze the diagnostic performance of MDA-MPR with CT for evaluating ACL structural continuity.

METHODS

A total of 145 patients with highly suspected ACL injury admitted to our hospital between January 2016 and May 2021 were retrospectively enrolled. All patients had undergone examination with MRI, CT, and arthroscopy. Taking arthroscopy results as the gold standard, the diagnostic accuracy for identifying ACL rupture by MRI and MDA-MPR with CT were compared.

RESULTS

The receiver operator characteristic curves demonstrated that both MRI and MDA-MPR with CT performed well in the diagnosis of ACL tears. The sensitivities of MRI and MDA-MPR with CT for diagnosing complete ACL tears were 95.16% (59/62) and 90.32% (56/62), respectively. Their specificities in this regard were 77.11% (64/83) and 84.34% (70/83), respectively. MRI had a higher sensitivity but MDA-MPR with CT had a higher specificity for detecting complete ACL tears, and the differences were statistically significant (p <.05). The sensitivities of diagnosing partial ACL tears using MRI and MDA-MPR with CT were 78.79% (26/33) and 75.76% (25/33), respectively, while the specificities were 86.61% (97/112) and 90.18% (101/112), respectively. These differences were non-significant (p >.05).

CONCLUSION

MDA-MPR with CT has high diagnostic efficiency for ACL injuries, especially in the diagnosis of complete ACL tears.

A finite element analysis of relationship between fracture, implant and tibial tunnel

The purpose of this article was to use finite element analysis (FEA) to study the relationship of tibial tunnel (TT) with fracture pattern and implants. A computed tomography scan of full-length tibia and fibula was obtained. Models were built after three-dimensional reconstruction. The corresponding plates and screws were constructed and assembled together with fracture models. FEA was performed and contourplots were output. The Von Mises stresses of nodes and displacements of elements were extracted. Student’s t test was used to compare the values of Von Mises stresses and displacements between corresponding models. Differences in Von Mises stresses and displacements of fragments and implants between models with and without TT were nearly all statistically significant. However, the displacements of fragments and implants for all models were < 2 mm. TT in fracture models had larger Von Mises stresses than TT in intact tibial model. However, displacements of TT in fracture models showed similar or even smaller results to those in intact tibial model. Although almost all the tested parameters were statistically significant, differences were small and values were all below the clinical threshold. This study could promote open reduction and internal fixation with one-stage reconstruction for treatment of tibial plateau fractures associated with anterior cruciate ligament (ACL) ruptures.

Arthroscopy-assisted surgery: The management of posterolateral tibial plateau depression fracture accompanying ligament injury: A case series and review of the literature

Tibial plateau fractures are multiple fracture patterns associated with soft-tissue injuries. Among which, the combined existence of posterolateral tibial plateau depression fracture with anterior cruciate ligament (ACL) rupture has been reported rarely. Meanwhile, surgical method for the treatment of depression fracture is fairly complex. The aim of this article is to show a case series of this unusual injury pattern and the therapy of posterolateral tibial plateau depression fracture accompanying ACL rupture. In our treatment, arthroscopy assisted reduction of depression fracture and ACL reconstruction reduces surgical trauma and leads to good functional recovery. We also review the current literature.

Incidence and Prognostic Significance of the Segond Fracture in Patients Undergoing Anterior Cruciate Ligament Reconstruction

BACKGROUND

The Segond fracture is an avulsion of the anterolateral tibia that can be found in patients with an anterior cruciate ligament (ACL) tear. It is currently unclear if the Segond fracture needs treatment or if it heals spontaneously and if it is associated with an increased risk of failure after ACL reconstruction.

PURPOSE

To identify the incidence and spontaneous healing rate of Segond fractures in a consecutive cohort of patients undergoing ACL reconstruction and to examine the predictive value of the Segond fracture on the risk of undergoing revision surgery.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective review of a cohort undergoing isolated ACL reconstruction between 2002 and 2016 was performed. Radiographs from the time of injury and preoperative radiographs were evaluated for Segond fractures and healed Segond fractures. Descriptive data were extracted from an internal quality database. Statistical analyses were performed to investigate risk of revision surgery and to compare across subgroups of patients.

RESULTS

A total of 1364 patients were included in the study. The incidence of Segond fractures was 7.4%. In addition, 10.4% of patients displayed signs of healed Segond fractures. In total, 15.2% of patients had either 1 or both findings. The overall healing response of the fracture was 35.6%. Those with Segond fractures were older (P = .014) and had a shorter interval from injury to surgery (P = .003) as compared with the rest of the cohort. The incidence of Segond fractures was significantly higher in those injured during downhill skiing as compared with other injury mechanisms (P = .04). The Segond fracture did not represent an increased risk of undergoing revision when compared with the control group (not significant).

CONCLUSION

The incidence of conventional Segond fractures in patients with ACL injury was found to be in accordance with former studies. Accounting for the high incidence of healed Segond fractures, a much higher incidence (15%) was seen. Although the spontaneous healing rate from initial radiographs to preoperative imaging was only 36%, the presence of Segond fractures did not represent a higher risk of undergoing revision surgery.

Avulsion fracture of the medial collateral ligament association with Segond fracture

The Segond fracture is a tibial avulsion injury of the insertion of the middle third of the lateral capsular ligament that is typically associated with anterior cruciate ligament and meniscal tears. The classically assigned mechanism of injury is a combination of internal rotation and varus stress. We report two cases of Segond fractures that presented with a variant pattern including osseous avulsion injuries of the medial collateral ligament at the femoral origin, anterior cruciate ligament tear, and pivot shift-type osseous contusion pattern, suggesting an alternative mechanism of injury that includes dominant valgus stress and external rotation components. Awareness of this pattern may aid radiologists, surgeons, and sport medicine physicians in the accurate diagnosis of this injury complex and initiation of appropriate treatment in a timely fashion.

Open reduction and internal fixation in a one-stage anterior cruciate ligament reconstruction surgery for the treatment of tibial plateau fractures: A case report and literature review

Treatment of tibial plateau fractures associated with anterior cruciate ligament (ACL) injuries can be challenging. Maintaining the joint surface and axis are two main principles for the management of patients with tibial plateau fractures. Herein, we describe a patient with tibial plateau fracture of Schatzker type VI associated with complete ACL rupture. Although in a two-stage reconstruction surgery for treatment of its rupture seem to be accepted by most orthopaedic surgeons in cases of ACL injuries, we treated our patient with ORIF in a one-stage ACL reconstruction surgery. At the 1-year follow-up, the patient gained full range of motion and was functioning well. We reviewed the literature on performing ORIF in a one-stage ACL reconstruction for the treatment of tibial plateau fractures, which seemed to be a reasonable management approach that supported its use for the treatment of this patient.

[Research progress on hyperextension tibial plateau fractures]

Objective

To summarize the progress in the treatment of hyperextension tibial plateau fractures.

Methods

Related literature concerning hyperextension tibial plateau fractures was reviewed and analyzed in terms of injury mechanisms, clinical patterns, and treatment outcomes.

Results

Hyperextension tibial plateau fractures is a specific type of hyperextension knee injuries, which is happened with the knee in over-extended position (<0°) and characterized by fracture and concomitant ligament injury. It can be classified into 4 patterns: marginal avulsion fractures, unicondylar anteromedial fractures, anterolateral fractures, and bicondylar fractures. The failure of structures occurs according to the diagonal injury mechanism characterized by anterior compression fractures and posterior tension ruptures. It is noted as a rule that a smaller anterior fragment is more likely to accompany by a posterior ligament rupture. Unicondylar anteromedial fracture pattern is caused by hyperextension varus mechanism and usually accompanied by posterolateral corner rupture. Bicondylar hyperextension injury is characterized by posterior metaphyseal cortical tension rupture, anterior articular depression, and reversed posterior slope.

Conclusion

Currently there is no consensus on the treatment of hyperextension tibial plateau fractures. Further basic and clinical studies are needed.

Technical note: Anterior cruciate ligament reconstruction in the presence of an intramedullary femoral nail using anteromedial drilling

AIM

To describe an approach to anterior cruciate ligament (ACL) reconstruction using autologous hamstring by drilling via the anteromedial portal in the presence of an intramedullary (IM) femoral nail.

METHODS

Once preoperative imagining has characterized the proposed location of the femoral tunnel preparations are made to remove all of the hardware (locking bolts and IM nail). A diagnostic arthroscopy is performed in the usual fashion addressing all intra-articular pathology. The ACL remnant and lateral wall soft tissues are removed from the intercondylar, to provide adequate visualization of the ACL footprint. Femoral tunnel placement is performed using a transportal ACL guide with desired offset and the knee flexed to 2.09 rad. The Beath pin is placed through the guide starting at the ACL’s anatomic footprint using arthroscopic visualization and/or fluoroscopic guidance. If resistance is met while placing the Beath pin, the arthroscopy should be discontinued and the obstructing hardware should be removed under fluoroscopic guidance. When the Beath pin is successfully placed through the lateral femur, it is overdrilled with a 4.5 mm Endobutton drill. If the Endobutton drill is obstructed, the obstructing hardware should be removed under fluoroscopic guidance. In this case, the obstruction is more likely during Endobutton drilling due to its larger diameter and increased rigidity compared to the Beath pin. The femoral tunnel is then drilled using a best approximation of the graft’s outer diameter. We recommend at least 7 mm diameter to minimize the risk of graft failure. Autologous hamstring grafts are generally between 6.8 and 8.6 mm in diameter. After reaming, the knee is flexed to 1.57 rad, the arthroscope placed through the anteromedial portal to confirm the femoral tunnel position, referencing the posterior wall and lateral cortex. For a quadrupled hamstring graft, the gracilis and semitendinosus tendons are then harvested in the standard fashion. The tendons are whip stitched, quadrupled and shaped to match the diameter of the prepared femoral tunnel. If the diameter of the patient’s autologous hamstring graft is insufficient to fill the prepared femoral tunnel, the autograft may be supplemented with an allograft. The remainder of the reconstruction is performed according to surgeon preference.

RESULTS

The presence of retained hardware presents a challenge for surgeons treating patients with knee instability. In cruciate ligament reconstruction, distal femoral and proximal tibial implants hardware may confound tunnel placement, making removal of hardware necessary, unless techniques are adopted to allow for anatomic placement of the graft.

CONCLUSION

This report demonstrates how the femoral tunnel can be created using the anteromedial portal instead of a transtibial approach for reconstruction of the ACL.