The Inlet and Outlet Ratio: Retrospective and Prospective Study on an Improved Diagnostic Ultrasound Tool for Carpal Tunnel Syndrome.

Purpose: This study hypothesized that ratios of sonographic cross-sectional areas (CSAs) throughout the median nerve provide a more reliable tool for diagnosing carpal tunnel syndrome (CTS) than a single CSA value. We first tested this hypothesis in a retrospective cohort and subsequently confirmed it in a prospective blinded case-control series. Methods: Seventy patients were included in the retrospective study, and 50 patients and matched controls were included for the prospective study. We evaluated 4 CSAs, at the forearm, inlet, tunnel, outlet, and their ratios (Rforearm, Rinlet, Routlet, Routlet forearm) to evaluate compression of the median nerve. All patients underwent nerve conduction studies. For the prospective cohort, Disabilities of the Arm, Shoulder, and Hand scores and Boston Carpal Tunnel Questionnaire scores were evaluated, and ultrasound was performed by 2 examiners for each participant. Results: The Boston and Disabilities of the Arm, Shoulder, and Hand scores showed worse subjective function in patients with CTS than in controls. Three ultrasonography parameters (CSAs at the inlet, Rinlet, and Routlet) correlated significantly with subjective function. Age and Rinlet were significantly correlated with severity of CTS in the nerve conduction studies. In both the retrospective and prospective patient groups, the numbers of CSAs at the inlet and outlet were significantly higher than that of CSAs at the tunnel, whereas in the control group, no such compression was found. Of the single measurements, CSAs at the inlet had the best diagnostic performance with an optimized cutoff of 11.75 mm2. The Rinlet and Routlet ratios performed even better and showed the highest adjusted odds ratios for predicting CTS of all parameters (cutoff Rinlet, 1.25; Routlet, 1.45). Inter-observer correlation was generally high, with better values for single CSAs than for ratios. Conclusions: The 3 CSA measurements of the median nerve and the associated ratios improved diagnostic power for ultrasonography in CTS in our study. Type of study/level of evidence: Diagnostic I.

Outcomes of acute perilunate injuries-a systematic review.

PURPOSE: The objective of this systematic review was to perform epidemiological as well as clinical, radiological and patient-reported outcome analysis of surgically treated perilunate dislocations and fracture dislocations (PLDs and PLFDs) based on the so far largest pooled patient population to date. MATERIAL AND METHODS: This systematic review was written according to the updated guideline for reporting systematic reviews by the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement. A comprehensive literature search of Pubmed, Embase, CENTRAL, and CINAHL databases was performed. All studies reporting on complications, radiological, functional and/or patient-reported outcomes of surgically treated acute PLDs and PLFDs with a minimum follow-up of 12 months were included. RESULTS: Twenty-six studies encompassing 550 patients with 553 operatively treated acute perilunate injuries (106 PLDs and 447 PLFDs) were included. The overall postoperative complication rate was 15.0% with secondary reduction loss representing the main contributing factor (10.1%). The overall reoperation rate was 10.4% and the incidence of salvage procedures was 2.8%. The risk for secondary reduction loss was higher for PLD than for PLFD injuries (24.2% vs. 7.0%, relative risk [RR] 3.5, 95% confidence interval [CI] 1.6-7.5). There was a higher overall complication rate for the combined dorsopalmar approach when compared to the isolated dorsal approach (17.4% vs. 8.4%, RR 0.5, 95% CI 0.2-1.0, number needed to treat [NNT] 11.2) and for open surgery versus arthroscopic surgery (17.4% vs. 4.8%, RR 0.3, 95% CI 0.1-0.9, NNT 8.0). A significant correlation was found between radiological osteoarthritis (rOA) and follow-up duration of the individual studies, while functional and patient-rated outcomes were comparable. CONCLUSIONS: Regardless of surgical technique, PLFDs appear to be less susceptible to secondary reduction loss than PLDs. Whenever possible, less invasive (e.g. arthroscopic) surgery should be performed to minimize postoperative complications. The rate of rOA is high and increases significantly with follow-up duration. Interestingly, rOA does not seem to correlate with reduced wrist function nor patient dissatisfaction and the need for salvage surgery is surprisingly rare. LEVEL OF EVIDENCE: Systematic review of level IV studies.

The effects of optimizing blood inflow in the pedicle on perforator flap survival: A pilot study in a rat model.

BACKGROUND: Perforator flaps have led to a revolution in reconstructive surgery by reducing donor site morbidity. However, many surgeons have witnessed partial flap necrosis. Experimental methods to increase inflow have relied on adding a separate pedicle to the flap. The aim of our study was to experimentally determine whether increasing blood flow in the perforator pedicle itself could benefit flap survival. METHODS: In 30 male Lewis rats, an extended posterior thigh perforator flap was elevated and the pedicle was dissected to its origin from the femoral vessels. The rats were assigned to three groups: control (group I), acute inflow (group II) and arterial preconditioning (group III) depending on the timing of ligation of the femoral artery distal to the site of pedicle emergence. Digital planimetry was performed on postoperative day (POD) 7 and all flaps were monitored using laser Doppler flowmetry perioperatively and postoperatively in three regions (P1-proximal flap, P2-middle of the flap, P3-distal flap). RESULTS: Digital planimetry showed the highest area of survival in group II (78.12%±8.38%), followed by groups III and I. The laser Doppler results showed statistically significant higher values in group II on POD 7 for P2 and P3. At P3, only group II recorded an increase in the flow on POD 7 in comparison to POD 1. CONCLUSIONS: Optimization of arterial inflow, regardless if performed acutely or as preconditioning, led to increased flap survival in a rat perforator flap model.