Long-term prevalence and impact of glenohumeral osteoarthritis after Latarjet-Patte procedure for anterior instability.

INTRODUCTION: The Latarjet procedure provides satisfactory functional results, with low rates of recurrence. It is, however, sometimes claimed to induce osteoarthritis due to the positioning of the bone-block and hardware. The aims of the present study were to assess the long-term prevalence of osteoarthritis following the procedure, to determine risk factors and assess clinical impact. The study hypothesis was that osteoarthritis risk can be reduced by good bone-block positioning. The secondary objective was to assess long-term recurrence of instability. MATERIALS AND METHODS: Out of a cohort of 102 patients (106 shoulders) operated on between 1984 and 1998, 77 had complete radiology files for analysis in a previous study published in 2003. Forty-four of these patients were seen again for clinical and radiological assessment at a mean 22 years' follow-up, to be compared to results previously reported at 8 years. Clinical assessment comprised range of motion and Constant and Walch-Duplay scores. X-rays were taken systematically to determine Samilson osteoarthritis stage; 31 patients also underwent CT. RESULTS: In the 44 patients, the rate of osteoarthritis was 34.1%. 90.9% of patients were satisfied. Mean Constant score was 83.5±14 and mean Walch-Duplay score was 71.6±23.4. Advanced age at surgery and at assessment, length of follow-up and age >30 years at first episode of instability were the main factors for onset of osteoarthritis, independently of surgery. Lateral bone-block overhang correlated with onset of osteoarthritis: 71.4%, versus 16.7% in medial or flush bone-block (p=0.0004). Humeral notch, glenoid bone defect and number of preoperative episodes of instability were unrelated to onset of osteoarthritis. Lateral bone-block overhang was the only risk factor related to surgery. The clinical impact of the osteoarthritis was significant only in advanced stages (Samilson 3 and 4). CONCLUSION: Lateral bone-block overhang was the only surgical risk factor for osteoarthritis in the long-term. Strict coracoid positioning is therefore essential, and could be facilitated by specific instrumentation and by arthroscopy. LEVEL OF EVIDENCE: IV; retrospective study.

Arthroscopic Bankart Repair Versus Immobilization for First Episode of Anterior Shoulder Dislocation Before the Age of 25: A Randomized Controlled Trial.

BACKGROUND: The risk of recurrence after the first episode of anterior shoulder dislocation is high with nonoperative treatment in younger patients. PURPOSE/HYPOTHESIS: The aim of this study was to compare the results of arthroscopic Bankart repair and nonoperative treatment for shoulder dislocation in patients younger than 25 years, with a minimum of 2 years of follow-up. The hypothesis was that surgery would decrease the risk of recurrence. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: We included patients aged between 18 and 25 years after a first episode of anterior shoulder dislocation and divided them into 2 groups. The first group was treated surgically with an arthroscopic Bankart repair within 2 weeks after the dislocation; the second group was treated nonoperatively. Both groups were immobilized for 3 weeks in internal rotation and followed the same physical therapy protocol. Standard radiography and computed tomography were performed immediately after reduction of the dislocation, and follow-up was performed at 3, 6, 12, and 24 months. The primary outcome measure was instability recurrence, defined as another anterior shoulder dislocation requiring closed reduction by another person (the patient was unable to reduce the dislocated joint themselves), a subluxation, or a positive apprehension test. Secondary outcome measures included range of motion, return to sport, and functional scores such as the short version of the Disabilities of the Arm, Shoulder and Hand score the Walch-Duplay score, and the Western Ontario Shoulder Instability Index (WOSI). RESULTS: A total of 20 patients were included in each group. The mean ± SD age was 21 ± 1.8 years, and there were 33 men (82.5%) and 7 women (17.5%) in the total sample. Recurrence of instability was significantly decreased in the surgical treatment group compared with the nonoperative group (2 [10%] vs 14 [70%], respectively; P = .0001). Fewer patients in the surgical treatment group versus the nonoperative group had another episode of dislocation (0 vs 6 [30%], respectively), subluxation (2 [10%] vs 13 [65%], respectively; P = .003), or a positive apprehension test (1 [5%] vs 11 [58%], respectively; P = .0005). The Walch-Duplay score (88.4 vs 70.3 points; P = .046) and WOSI (11.5 vs 17.7 points; P = .035) were significantly better in the surgical group versus the nonoperative group after a 2-year follow-up. Level of sport was the same or better in 89% of the surgical treatment group vs 53% of the nonoperative treatment group (P = .012). No surgical complication was recorded. We did not find any significant difference in range of motion. CONCLUSION: In patients with first-time shoulder dislocations, arthroscopic labral repair (Bankart procedure) reduced the risk of secondary shoulder dislocation and improved functional outcome versus nonoperative treatment after a 2-year follow-up. Surgical treatment after a first episode of shoulder dislocation could be offered as a primary treatment option in a younger population if these results are confirmed by larger studies with a longer follow-up. REGISTRATION: NCT03315819 (ClinicalTrials.gov identifier).

Extraction of Nystagmus Patterns from Eye-Tracker Data with Convolutional Sparse Coding.

The analysis of the Nystagmus waveforms from eye-tracking records is crucial for the clinical interpretation of this pathological movement. A major issue to automatize this analysis is the presence of natural eye movements and eye blink artefacts that are mixed with the signal of interest. We propose a method based on Convolutional Dictionary Learning that is able to automatically highlight the Nystagmus waveforms, separating the natural motion from the pathological movements. We show on simulated signals that our method can indeed improve the pattern recovery rate and provide clinical examples to illustrate how this algorithm performs.

Dual-energy computed-tomography-based discrimination between basic calcium phosphate and calcium pyrophosphate crystal deposition in vivo.

BACKGROUND: Dual-energy computed tomography (DECT) is being considered as a non-invasive diagnostic and characterization tool in calcium crystal-associated arthropathies. Our objective was to assess the potential of DECT in distinguishing between basic calcium phosphate (BCP) and calcium pyrophosphate (CPP) crystal deposition in and around joints in vivo. METHODS: A total of 13 patients with calcific periarthritis and 11 patients with crystal-proven CPPD were recruited prospectively to undergo DECT scans. Samples harvested from BCP and CPP calcification types were analyzed using Raman spectroscopy and validated against synthetic crystals. Regions of interest were placed in BCP and CPP calcifications, and the following DECT attenuation parameters were obtained: CT numbers (HU) at 80 and 140 kV, dual-energy index (DEI), electron density (Rho), and effective atomic number (Z eff). These DECT attenuation parameters were compared and validated against crystal calibration phantoms at two known equal concentrations. Receiver operating characteristic (ROC) curves were plotted to determine the highest accuracy thresholds for DEI and Z eff. RESULTS: Raman spectroscopy enabled chemical fingerprinting of BCP and CPP crystals both in vitro and in vivo. DECT was able to distinguish between HA and CPP in crystal calibration phantoms at two known equal concentrations, most notably by DEI (200 mg/cm3: 0.037 ± 0 versus 0.034 ± 0, p = 0.008) and Z eff (200 mg /cm3: 9.4 ± 0 versus 9.3 ± 0, p = 0.01) analysis. Likewise, BCP calcifications had significantly higher DEI (0.041 ± 0.005 versus 0.034 ± 0.005, p = 0.008) and Z eff (9.5 ± 0.2 versus 9.3 ± 0.2, p = 0.03) than CPP crystal deposits with comparable CT numbers in patients. With an area under the ROC curve of 0.83 [best threshold value = 0.0 39, sensitivity = 90. 9% (81.8, 97. 7%), specificity = 64.6% (50.0, 64. 6%)], DEI was the best parameter in distinguishing between BCP and CPP crystal depositions. CONCLUSION: DECT can help distinguish between crystal-proven BCP and CPP calcification types in vivo and, thus, aid in the diagnosis of challenging clinical cases, and in the characterization of CPP and BCP crystal deposition occurring in osteoarthritis.