Rotational malalignment in femoral nailing: prevention, diagnosis and surgical correction.

BACKGROUND AND AIM OF THE WORK: to review and discuss the literature about rotational malalignment during and after femoral nailing. METHODS: analysis of the literature on prevention and evaluation of rotation during femoral nailing, clinical and subjective consequences of malrotation and techniques used to correct the deformity, both in the acute and chronic phase. RESULTS: malrotation is very common after femoral nailing. The exact definition of a malrotated femur is controversial, but it is widely agreed that a rotational malalignment <10° is considered normal while >30° is a deformity which requires correction. The complaints of the patients with a malrotated femur can be various and can involve the hip, the knee or below the knee. The ability to compensate for the deformity while standing and walking may decrease the symptoms. Surgical correction is feasible with many techniques and devices: the procedure involving derotation, changing the locking screws and maintaining the nail is safe, reproducible and relatively easy. CONCLUSIONS: prevention of malrotation during femoral nailing is the cornerstone of successful operation outcomes. If rotational malalignment is suspected, prompt diagnosis and adequate surgical treatment are mandatory to overcome this common complication.

Treatment of cam-type femoroacetabular impingement.

PURPOSE: the aim of this study was to evaluate preliminary clinical and radiographic results of arthroscopic treatment of cam-type femoroacetabular impingement (FAI). METHODS: thirty-eight patients underwent hip arthroscopy for cam-type FAI between 2009 and 2012. Preoperative assessment was based on clinical examination, modified Harris Hip Score (mHHS) and radiographic examination with anteroposterior pelvis, frog-leg and Lequesne views. The patients' clinical conditions at follow-up were assessed using the mHHS administered as a telephone survey. Radiographic outcome measurements evaluated pre and postoperatively were the alpha angle and femoral head-neck offset. RESULTS: the patients were clinically evaluated at a mean follow-up of 36 months. Radiographic follow-up was performed at an average of 12.7 months. Thirty of the 38 patients (79%) were satisfied with the results of the arthroscopic procedure. A total of nine patients subsequently underwent a total hip replacement. All 30 patients who declared themselves satisfied recorded an mHHS increase; in particular, the mHHS increased from a mean of 52.9 preoperatively (range: 27.5-82.5) to a mean of 85.6 postoperatively (range: 45.1-100.1). Three significant differences between the two groups of patients (satisfied and not satisfied) were recorded: mean age, alpha angle and BMI were all significantly greater in the patients who were not satisfied with the treatment. CONCLUSIONS: a crucial aspect in order to obtain good clinical outcomes of arthroscopic treatment of cam-type impingement is correct selection of patients who are likely to benefit from this kind of surgery. Hip arthroscopy should be avoided in patients aged over 50 years with risk factors for early osteoarthritis (high BMI and a significantly increased alpha angle). LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Semitendinosus Tendon Transfer Associated With Distal Alignment for Patella Alta in a Patient With Recurrent Dislocations.

Patellofemoral instability is characterized by pain during normal daily activities and frequent dislocation events. In the reported case, an adolescent girl, aged 15 years, affected by left patellofemoral instability, underwent surgery with a double technique comprising tibial tubercle distalization and medial patellofemoral ligament reconstruction. In case of patella alta associated with patellofemoral instability, surgical treatment should focus on medial patellofemoral ligament repair and on recurrent instability prevention.

Thermally stabilized PCF-based sensor for temperature measurements up to 1000 degrees C.

We report on the development of a stable Photonic Crystal Fiber (PCF) based two-mode interferometric sensor for ultra-high temperature measurements (up to 1000 degrees C). The device consists of a stub of PCF spliced to standard optical fiber. In the splice regions, the voids of the PCF are fully collapsed, thus allowing the excitation and recombination of two core modes. The device spectrum exhibits sinusoidal interference pattern which shifts with temperature. We show that, despite being compact and robust, the proposed sensor head needs a quite long burn in (thermal annealing) to achieve an adequate and stable functionality level. The burn in process eliminates the residual stress in the fiber structure, which had been accumulated during the drawing phase, and changes the glass fictive temperature.

Photonic-crystal-fiber-enabled micro-Fabry-Perot interferometer.

We report on the fabrication of a monolithic fiber Fabry-Perot interferometer whose cavity is a microscopic air bubble. The latter is formed when splicing together a conventional single-mode fiber and an index-guiding photonic crystal fiber with the standard arc-discharge technique. Spherical microcavities with diameters ranging from 20 to 58 microm were fabricated with such a technique. The interferometers exhibited low thermal sensitivity (less than 1.0 pm/ degrees C), high mechanical strength, broad operation wavelength range, and fringe contrast in the 8-12 dB range. The applications of the interferometers for strain sensing (up to 5000 micro(epsilon) is demonstrated.