Brian C. Lau

Inter- and intra-rater reliability of patellofemoral kinematic and contact area quantification by fast spin echo MRI and correlation with cartilage health by quantitative T1ρ MRI

BACKGROUND Patellar maltracking is a leading cause of patellofemoral pain syndrome (PFPS). The aim of this study was to determine the inter- and intra-rater reliability of a semi-automated program for magnetic resonance imaging (MRI) based patellofemoral kinematics. METHODS Sixteen subjects (10 with PFPS [mean age 32.3; SD 5.2; eight females] and six controls without PFPS 19 [mean age 28.6; SD 2.8; three females]) participated in the study. One set of T2-weighted, fat-saturated fast spin-echo (FSE) MRIs were acquired from each subject in full extension and 30° of knee flexion. MRI including axial T1ρ relaxation time mapping sequences was also performed on each knee. Following image acquisitions, regions of interest for kinematic MRI, and patellar and trochlear cartilage were segmented and quantified with in-house designed spline- based MATLAB semi-automated software. RESULTS Intraclass Correlations Coefficients (ICC) of calculated kinematic parameters were good to excellent, ICC > 0.8 in patellar flexion, rotation, tilt, and translation (anterior -posterior, medial -lateral, and superior -inferior), and contact area translation. Only patellar tilt in the flexed position and motion from extended to flexed state was significantly different between PFPS and control patients (p=0.002 and p=0.006, respectively). No significant correlations were identified between patellofemoral kinematics and contact area with T1ρ relaxation times. CONCLUSIONS A semi-automated, spline-based kinematic MRI technique for patellofemoral kinematic and contact area quantification is highly reproducible with the potential to help better understand the role of patellofemoral maltracking in PFPS and other knee disorders. LEVEL OF EVIDENCE Level IV.

Acute Fixation of Type IV and V Acromioclavicular Separations: An Internal Splint Technique

Background: There is no standard method for the surgical treatment of acromioclavicular (AC) joint separations. Current techniques have associated complications, including need for device removal, coracoid fracture, and inadequate reduction. Purpose: To evaluate the clinical outcomes of an internal splint technique without graft augmentation or rigid fixation to treat acute Rockwood type IV and V AC joint injuries. Study Design: Case series; Level of evidence, 4. Methods: A retrospective analysis was performed of 26 patients who underwent a novel internal splint fixation technique between 2011 and 2016. Patients had type IV (n = 2) and type V (n = 24) acute AC separations. The mean time to surgery was 13.7 days (range, 1-28 days). The surgical technique included an open approach with coracoclavicular suture and tape fixation and AC suture fixation. Range of motion, strength, and radiographs were evaluated after surgery. Patient follow-up included the DASH (Disabilities of the Arm, Shoulder and Hand) questionnaire at a mean 3.3 years postoperatively (range, 6 months–8.6 years). DASH questionnaires were obtained for all patients via email. Patients were also surveyed on cosmetic appearance and willingness to undergo the operation again. Results: All patients regained full strength and range of motion following surgery. All postoperative radiographs demonstrated well-maintained reduction of the AC joint. The mean DASH score was 3.4 at final follow-up, and 23 of 26 respondents were satisfied with their postoperative shoulder appearance. There were no reoperations, and all patients stated that they would have the operation again given the same circumstances. Conclusion: The results of this study demonstrate a reliable new technique for acute fixation of type IV or V AC joint injuries via an internal splint construct. This technique enables reduction in the coronal and sagittal planes without the need for graft augmentation or a rigid implant, allowing healing of the coracoclavicular and AC ligaments.

Clinical measurements versus patient-reported outcomes: analysis of the American Shoulder and Elbow Surgeons physician assessment in patients undergoing reverse total shoulder arthroplasty

Background The American Shoulder and Elbow Surgeons (ASES) score is composed of a patient-reported portion and a physician assessment. Although the patient-reported score is frequently used to assess postoperative outcomes after shoulder arthroplasty, no previous studies have used the physician-assessment component. This study evaluated the relationship of the ASES physician-assessment measurements with patient-reported shoulder and general health outcomes. Methods A retrospective review of a prospectively collected multicenter database was used to analyze patients who underwent primary reverse total shoulder arthroplasty (RTSA) from 2012 to 2015 with a minimum 2-year follow-up. ASES physician-assessment and patient-reported components and 12-Item Short Form Health Survey (SF-12) general health questionnaires were obtained preoperatively and 2 years postoperatively. The relationship between ASES physician measurements with ASES patient-reported outcome (PRO) scores and SF-12 Physical and Mental domain scores was assessed with Pearson correlation coefficients. Results Included were 74 patients (32 men; mean age, 69.2 years; body mass index, 29.4 kg/m2). Preoperative physician measurements and PRO scores were not significantly correlated. Postoperatively, only the ASES physician-measured active (R = 0.54, P < .01) and passive forward flexion (R = 0.53, P < .01) demonstrated moderate correlation with ASES patient scores. The remaining clinical measurements had no significant correlations with ASES patient or SF-12 scores. During the 2-year period, only improvements in active forward flexion correlated with improvements in ASES patient scores (R = 0.36, P < .01). Conclusions Little correlation exists between clinical measurements from the ASES physician component and PROs, including the ASES patient-reported and SF-12 general health surveys, in RTSA patients. Improvement in active forward flexion is the only clinical measurement correlated with PRO improvement at 2 years.

Radiographic comparison of adolescent athletes with elbow osteochondritis dissecans to ulnar collateral ligament injuries and controls

BACKGROUND There are excellent data supporting recommendations to prevent elbow injuries (osteochondritis dissecans [OCD] and ulnar collateral ligament [UCL] injuries), such as pitch count and pitch type in baseball, but anatomic risk factors have not been thoroughly examined. This study aimed to evaluate radiographic measurements in adolescents with elbow OCD lesions or UCL injuries and controls. METHODS We retrospectively identified adolescent patients between 2011 and 2016 with isolated capitellum OCD, UCL tear, or normal elbows based on magnetic resonance imaging. Nineteen patients (mean age, 13.5 years) had isolated OCD defects of the capitellum, 8 patients (mean age, 16.9 years) had isolated UCL complete tear, and the remaining 16 patients (mean age, 14.6 years) were normal controls. Radiographic measurements from corresponding anterior-posterior elbow radiographs were taken, including carrying angle, distal humeral articular surface angle, and radial neck-shaft angle. On the lateral radiograph, anterior angulation of the articular surface of distal humerus was measured. RESULTS Significant differences were observed in carrying angle between controls (15.7°) and OCD patients (11.6°; P = .03) as well as between controls and UCL patients (10.3°, P = .02), with the OCD and UCL patients tending to be in more varus. Significant differences were also found between controls (88.5°) and OCD patients (93.6°; P = .01) and between controls and UCL patients (93.3°; P = .03) in distal humeral articular surface angle, with OCD and UCL patients with increased valgus at the distal humerus articular surface. There were no significant differences between groups in radial neck-shaft angle or anterior angulation of articular surface of distal humerus. CONCLUSIONS Patients with OCD and UCL injuries have anatomic differences compared with normal controls that can be measured radiographically.