The AO classification system for tibial plateau fractures: An independent inter and intraobserver agreement study.

PURPOSE: Classifying tibial plateau fractures is paramount in determining treatment regimens and systemizing decision making. The original AO classification described by Müller in 1996 and the Schatzker classification of 1970 are the most cited classifications for tibial plateau fractures, demonstrating substantial to almost perfect agreement. The main problem with these classifications schemes is that they lack the detail required to convey the variety of fracture patterns encountered. In 2018, the AO foundation published a new classification system for proximal tibia fractures, highlighting a more complete and detailed number of categories and subcategories. We sought to independently determine inter and intraobserver agreement of the AO classification system, compared to the previous systems described by Müller and Schatzker. METHODS: One hundred seven consecutive tibial plateau fractures were screened, and a representative data set of 69 was created. Six independent evaluators (three knee surgeons, three senior orthopedic residents) classified the fractures using the original AO, the Schatzker and the new AO classifications. After six weeks, the 69 cases were randomized and reclassified by all evaluators. The Kappa coefficient (k) was calculated for inter- and intraobserver correlation and is expressed with 95% confidence intervals. RESULTS: interobserver agreement was moderate for all three classifications. k = 0.464 (0.383-0.560) for the original AO; k = 0.404 (0.337-0.489) for Schatzker; and k = 0.457 (0.371-0.545) for the base categories of the new AO classification. The inclusion of subcategories and letter modifiers to the new classification worsened agreement to k = 0.358 (0.302-0.423) and k = 0.174 (0.134-0.222), respectively. There were no significant differences between knee surgeons and residents for the new classification. Intra-observer correlation was also moderate for each of the scores: k = 0.630 (0.578-0.682) for the original AO; k = 0.623 (0.569-0.674) for Schatzker; and k = 0.621 (0.566-0.678) for the new AO base categories; without differences between knee surgeons or residents. CONCLUSIONS: This study demonstrated an adequate inter and intra-observer agreement for the new AO tibial plateau fractures classification system for its base categories, but not at the subcategory or letter modifier levels.

Tibial Cut Accuracy in Mechanically Aligned Total Knee Arthroplasty Using Extensor Hallucis Longus Tendon to Determine Extramedullary Tibial Guide Position.

This study aimed to determine the tibial cut (TC) accuracy using extensor hallucis longus (EHL) tendon as an anatomical landmark to position the total knee arthroplasty (TKA) extramedullary tibial guide (EMTG), and its impact on the TKA mechanical alignment (MA). We retrospectively studied 96 TKA, performed by a single surgeon, using a femoral tailored intramedullary guide technique. Seventeen were prior to the use of the EHL and 79 used the EHL tendon to position the EMTG. We analyzed preoperative and postoperative standing total lower extremity radiographs to determine the tibial component angle (TCA) and the correction in MA, comparing pre-EHL use and post-EHL technique incorporation. Mean TCA was 88.89 degrees and postoperative MA was neutral in 81% of patients. Pre- and postoperative MAs were not correlated. As a conclusion of this study, using the EHL provides a safe and easy way to determine the position of EMTG.

Variability of the capsular anatomy in the rotator interval region of the shoulder.

PURPOSE: Anterior shoulder anatomy is as complex and variable as its descriptive terminology. A detailed understanding of normal anatomic variability is critical to accurate performance, description, and evaluation of the procedures involving the rotator interval. We aimed to define, arthroscopically, the anatomic variability in the rotator interval region of the shoulder and to compare these results to the findings of previous cadaveric studies. METHODS: The rotator interval anatomy of 104 consecutive patients was classified according to the system of DePalma. Anatomic variability was evaluated and compared with findings of previous authors. RESULTS: Shoulders were classified as follows: 59% type 1 (rotator interval capsular opening [RICO] superolateral to the MGHL); 1% type 2 (RICO inferomedial to the middle glenohumeral ligament [MGHL]); 22% type 3 (2 RICOs: 1 above and 1 below the MGHL); 9% type 4 (large RICO, no MGHL); 0% type 5 (the MGHL is manifested as 2 small RICOs); 7% Type 6 (no RICO); and 3% distinct Buford complex. We found a larger percentage of type 1 shoulders and a lower percentage of type 3 shoulders relative to prior open cadaveric dissections. No difference in the distribution of DePalma types was noted based surgical indication. CONCLUSIONS: The anatomy of the rotator interval as viewed arthroscopically is complex and variable. While DePalma types 1 and 3 are most commonly encountered, other anatomic variants are frequent and should be considered when assessing and manipulating structures in region of the rotator interval and anterior shoulder.

Brief report: The sensitivity of motor responses for detecting catheter-nerve contact during ultrasound-guided femoral nerve blocks with stimulating catheters.

BACKGROUND: We determined the sensitivity of motor responses evoked by stimulating catheters in determining catheter-nerve contact using ultrasonography as reference. METHODS: Femoral nerves were contacted using stimulating catheters under ultrasonography scanning in 25 patients. The output current was increased from its minimum until quadriceps muscle contraction occurred. The sensitivity of the motor response in determining catheter-nerve contact was calculated using 0.5 mA as current threshold. RESULTS: The current required for catheter stimulation to evoke a motor response ranged between 0.18 and 2.0 mA. Muscle contraction in response to 0.5 mA occurred in 16 of 25 subjects. The sensitivity of motor response for nerve stimulation was 64% (95% confidence interval: 0.43, 0.82). CONCLUSIONS: The absence of muscle responses at a stimulating current≤0.5 mA does not necessarily indicate the absence of catheter-nerve contact.

Arthroscopic fixation of displaced tibial eminence fractures: a new growth plate-sparing method.

PURPOSE: Fractures of the tibial eminence can be treated arthroscopically. Numerous ways to attach an anterior cruciate ligament avulsion from the tibial eminence have been designed. This report describes a new physis-sparing reduction and fixation technique using an anchor passing nonabsorbable braided sutures through the substance of the anterior cruciate ligament, holding the avulsed bone fragment by tying a locking knot. This study was performed to evaluate a consecutive group of patients who underwent reduction and fixation of tibial avulsion fractures fixed with an anchor with sutures. METHODS: The evaluation was performed by use of objective and subjective International Knee Documentation Committee (IKDC) scores, KT-1000 measurement (MEDmetric, San Diego, CA), Lachman and pivot-shift tests, and Lysholm score. RESULTS: The global IKDC objective score was normal (A) in 4 knees and nearly normal (B) in 3, without extension or flexion limitations. The mean IKDC subjective score was 92 out of 100 (range, 86 to 98). The results of the anterior drawer, Lachman, and pivot-shift tests were negative. The mean Lysholm score improved from 29 to 94. The mean side-to-side difference in anterior tibial translation was 2 mm (range, 1 to 3 mm). CONCLUSIONS: Arthroscopic stabilization by use of an anchor with sutures was possible in all cases of tibial spine fracture. We were able to obtain excellent results in this series using this fixation method. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Simple solution for failure of trailing sutures when using the EndoButton in anterior cruciate ligament reconstruction: the "Rescue Rein".

In this article, we introduce the technique of adding a second suture in the distal hole of the EndoButton. This suture, the "Rescue Rein," is kept with the graft and is a simple solution for recovering the graft during anterior cruciate ligament reconstruction when the EndoButton becomes jammed within the femoral tunnel and the trailing sutures cannot be removed.