MRI findings of Stener-like lesion of the knee: A case series with surgical correlation.

PURPOSE: To describe the MRI findings of the "Stener-like" lesion of the knee and its distinction from simple medial collateral ligament (MCL) tear. A "Stener-like" lesion of the superficial medial collateral ligament is a tear involving the distal fibers, where the torn fibers become displaced superficial to the pes anserinus fibers, a displacement which can prevent healing. METHODS: Nine cases of Stener-like lesion were prospectively diagnosed on MRI. Retrospective, IRB-approved, HIPAA-compliant chart review was performed to determine correlation of surgical and MRI findings. Seven cases were surgically confirmed and are included in the series. RESULTS: MRI is useful in making the diagnosis of Stener-like lesions and prompting the surgeon to explore the distal MCL. Coronal MRI shows variable proximal retraction of the torn ligament. It has a lax contour and abuts the pes anserinus. The proximity of the torn ligament end to the pes can result in misdiagnosis of a partial tear. Axial images are useful to confirm position of the ligament superficial to the pes. All cases had associated tear of the deep MCL fibers, as well as sprains of the proximal superficial MCL. CONCLUSIONS: It is important to recognize the Stener-like lesion because this lesion is usually managed surgically, while most MCL tears are managed conservatively. The presence of injury to the proximal MCL is usually present, and may be a distractor from the distal injury. Care must be taken to include the distal attachment of the sMCL on coronal MRI images.

Subchondroplasty for the treatment of post-traumatic bone marrow lesions of the medial femoral condyle in a pre-clinical canine model.

This study characterizes long-term outcomes associated with subchondroplasty (SCP) treatment for impact-induced subchondral bone marrow lesions (BML) using a validated pre-clinical canine model. With IACUC approval, purpose-bred research hounds (n = 16) underwent arthroscopic impact injury (40N) to both medial femoral condyles. At 3 months, functional assessments, arthroscopy, and MRI were performed and knees (n = 32) were randomly assigned to SCP (3 ml fluoroscopically guided percutaneous injection of AccuFill BSM into BML bone defects) or sham injection (Control). Dogs were assessed at 3, 6, 12, and 24 months after treatment using functional assessments, radiographic evaluation, arthroscopy, and MRI. Dogs were humanely euthanatized at 3, 6, 12, or 24 months after treatment for gross, microCT, and histologic assessments. All knees had focal articular cartilage defects with associated subchondral BMLs, as well as clinical dysfunction, 3 months after injury. At the 3 and 6 months, SCP knees showed more functional impairment than Control knees, however, these differences were not statistically significant. At 1- and 2-year post-treatment, function in SCP knees was better than in Control knees with range of motion being significantly (p < 0.05) better for SCP. Radiographic, arthroscopic, MRI, gross, microCT, and histologic findings matched the functional assessments well with Control being associated with better results at the two early time points and SCP being associated with better results at 1 and 2 years. Clinical significance: SCP treatment using calcium phosphate bone void filler was associated with an initial increase in pain and dysfunction followed by symptomatic benefits for up to 2 years after treatment for post-traumatic femoral condyle BMLs in a preclinical canine model. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2709-2717, 2018.

Current Concepts in Rehabilitation for Traumatic Anterior Shoulder Instability.

PURPOSE OF REVIEW: The objectives of this review are to evaluate the current evidence-based literature and concepts surrounding rehabilitation in patients with anterior shoulder instability injuries and surgical repair. RECENT FINDINGS: The current literature evidence for shoulder rehabilitation for anterior shoulder instability and labral repair is limited. As a result, there are variations among surgeons and physical therapists in rehabilitation protocols after anterior shoulder instability injuries and repair. While general consensus on certain rehabilitation parameters exists, the evidence for the importance of rehabilitation and functional performance test for return to sport in future injury prevention is still lacking in literature. Rehabilitation after anterior shoulder instability injury and anterior labral repair is paramount in the injured or post-operative shoulder. Restoration of soft tissue mobility, dynamic glenohumeral joint stability, and balance and strength around the shoulder not only protect healing of injured or repaired soft tissues but also potentially minimizes future re-injury or recurrence risk.

Development of a Novel Canine Model for Posttraumatic Osteoarthritis of the Knee.

Translational models of posttraumatic osteoarthritis (PTOA) that accurately represent clinical pathology need to be developed. This study assessed a novel canine model for PTOA using impact injury. Impacts were delivered to the medial femoral condyle of dogs using a custom-designed impactor at 20, 40, or 60 MPa. Functional assessments and magnetic resonance imaging (MRI) were performed at 2 and 12 weeks, and arthroscopic and histologic assessments were performed at 12 weeks after injury. At 2 and 12 weeks, dogs had observable lameness, knee pain, effusion, loss in range of motion (ROM) and dysfunction in both hindlimbs with severity correlated strongly (r > 0.77) to impact level. At 12 weeks, function, pain, effusion, and ROM were significantly (p < 0.049) worse in knees impacted at 40 and 60 MPa compared with 20 MPa. MRI showed consistent cartilage and subchondral bone marrow lesions, and arthroscopy revealed synovitis and cartilage destruction in impacted knees, with increased severity for 40 and 60 MPa impacts. Histopathology was significantly (p = 0.049) more severe in 40 and 60 MPa and strongly correlated (r = 0.93) to impact level. This novel translational model appears to be valid for investigation of PTOA, including determination of temporal mechanisms of disease and preclinical testing for preventative and therapeutic strategies.

Pseudoaneurysm as a complication of ankle arthroscopy.

We present a case of a pseudoaneurysm of the anterior tibial artery following ankle arthroscopy with synovectomy, an extremely rare complication when standard anteromedial and anterolateral portals are used. The patient was diagnosed and treated with appropriate interventions which led to an uneventful recovery. Nevertheless, the potential sequelae of delayed diagnosis or misdiagnosis of the complication are dangerous; therefore, a high index of suspicion for a pseudoaneurysm must be maintained in the postoperative period.