Applications of statistical tests in hand surgery

Wound Complications Following Olecranon Fracture Fixation: Implant and Soft Tissue Considerations

BACKGROUND

The aim of this multicenter, retrospective, case-control series was to investigate patient- and treatment-specific factors associated with wound breakdown following olecranon fracture fixation.  Methods: We identified patients at our two participating academic centers who were operatively treated for olecranon fractures and those who subsequently underwent a re-operation secondary to postoperative wound breakdown. Demographic and historical information was collected, including BMI and Charlson comorbidity index (CCI) scores. The primary outcome measure was the standardized radiographic measurement of plate prominence and soft tissue thickness posterior to the plate tip.  Results: We identified 32 patients who underwent internal fixation and subsequent wound breakdown. This was compared to a cohort of 35 matched controls that did not have wound issues. Cases with wound breakdown were of higher energy, nine being open cases compared to two in the control group (p<0.05). No differences were identified in plate prominence, soft tissue thickness, and plate type.  Conclusions: Wound breakdown following olecranon fracture fixation is more commonly seen in high-energy open injuries. Plate prominence, soft tissue thickness, and patient-specific factors do not correlate with wound breakdown. Further investigation into the factors influencing plate placement and how they may contribute to wound complications is needed.

Allograft reconstruction for digital nerve loss

PURPOSE

To investigate the outcomes of digital nerve repairs using processed nerve allograft for defects measuring 30 mm or less.

METHODS

Seventeen patients with 21 digital nerve lacerations in the hand underwent reconstruction with processed nerve allograft. Outcome data for 14 patients with 18 digital nerve lacerations were available for analysis. Postoperative outcome data were recorded at a minimum of 12 months and an average of 15 months. The average nerve gap measured 11 mm (range, 5-30 mm). Outcome measures included postoperative sensory examination as assessed by Semmes-Weinstein monofilaments and static and moving 2-point discrimination. Pain was graded using a visual analog scale throughout the recovery period. In addition, patients completed the Quick Disabilities of the Arm, Shoulder, and Hand survey before and after surgery.

RESULTS

Using Taras outcome criteria, 7 of 18 (39%) digits had excellent results, 8 of 18 (44%) had good results, 3 of 18 (17%) digits had fair results, and none had poor results. At final follow-up, Semmes-Weinstein monofilament testing results ranged from 0.08 g to 279 g. Quick Disabilities of the Arm, Shoulder, and Hand scores recorded at the patient's first postoperative visit averaged 45 (range, 2-80), and final scores averaged 26 (range, 2-43). There were no signs of infection, extrusion, or graft reaction.

CONCLUSIONS

The data suggest that processed nerve allograft provides a safe and effective alternative for the reconstruction of peripheral digital nerve deficits measuring up to 30 mm.

Measuring treatment effectiveness: a guide to incorporating the principles of evidence-based medicine

Every year, hundreds of new surgical devices and techniques are introduced, and plastic surgeons must determine the associated risks, benefits, and costs of these options when incorporating these advances into their armamentarium. This article will discuss the elements of treatment effectiveness by applying the principles of evidence-based medicine to therapeutics. Current efforts to measure plastic surgery outcomes are evolving and rely on case series and retrospective cohort studies. This review will highlight the basic evidence-based medicine concepts and how they can potentially be applied to understand best practices in plastic surgery.

Gender and condylar differences in distal femur morphometry clarified by automated computer analyses

We elucidated the gender and condylar effects on distal femur morphology (DFM) while evaluating a newly developed computational framework that enables fully automated analyses of DFM in an objectively defined sagittal plane. Ninety high-resolution CT-acquired distal femur models from 51 males and 39 females were analyzed. The models were accurately characterized (mean least-squares fitting residual <0.16 mm), and re-oriented to a unified sagittal plane; three morphometric measures were extracted from each model: the semi-major (a) and semi-minor (b) axis lengths of the best-fitted ellipse, and the radius (r) of the smallest flexion facet-a circle with the smallest radius best-fitted to the posterior articulating surface. Statistical analyses employing nonparametric repeated-measures ANOVA found: no significance difference between condyles or between limbs in any of the morphometric measures; significant gender effects on a, b, and r, but no gender effect on the aspect ratio (a/b). An inspection of statistical distributions of medial-lateral condyle size differences also revealed a gender difference. The findings promote a better understanding of DFM and its relation to knee mechanics and have implications on computer-aided surgery of the knee and gender-specific implant design.