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.