Inadequacy of computed tomography for pre-operative planning of patellofemoral arthroplasty.

PURPOSE: To evaluate the accuracy of preoperative planning for patellofemoral arthroplasty (PFA) by comparing: (1) virtual implant positioning simulated on pre-operative images versus (2) real implant positioning from post-operative images. METHODS: The authors prospectively studied 15 patients that received a PFJ implant (Tornier, Montbonnot France). A pre-operative planning software was established to determine the size and position of the trochlear component. Pre-operative scans were used to perform virtual implantations by two different operators, which were then compared to the post-operative scans to calculate errors (ε) in implant positioning and intra-class correlation coefficients (ICC) for intra- and inter-observer repeatability. RESULTS: Analysis was performed for 13 patients, for whom agreement between virtual and real surgery was excellent for anteroposterior (AP) position (ICC = 0.84; ε max = 3.5 mm), fair for proximodistal (PD) position (ICC = 0.50; ε max = 9.5 mm), and poor for mediolateral (ML) position (ICC = 0.07; ε max = 9.0 mm). It was fair for flexum-recurvatum (FR) alignment (ICC = 0.53; ε max = 8.2°), poor for varus-valgus (VV) alignment (ICC = 0.34; ε max = 10.0°), and internal-external (IE) rotation (ICC = 0.34; ε max = 10.6°). CONCLUSIONS: Pre-operative planning was insufficiently accurate to follow intra-operatively, the greatest errors being angular alignment (VV and FR). The clinical relevance of these findings is that PFA is difficult to plan pre/operatively due to non-visibility of cartilage on CT scans and to trochlear dysplasia in most cases. LEVEL OF EVIDENCE: Prospective evaluation of operative tools on consecutive patients, Level III.

Correction of Patellofemoral Malalignment With Patellofemoral Arthroplasty.

BACKGROUND: The goal of patellofemoral arthroplasty (PFA) is to replace damaged cartilage and correct underlying deformities to reduce pain and prevent maltracking. We aimed to determine how PFA modifies patellar height, tilt, and tibial tuberosity-trochlear groove (TT-TG) distance. The hypothesis was that PFA would correct trochlear dysplasia or extensor mechanism malalignment. METHODS: The authors prospectively studied a series of 16 patients (13 women and 3 men) aged 64.9 ± 16.3 years (range 41-86 years) who received PFA. All knees were assessed preoperatively and 6 months postoperatively using frontal, lateral, and "skyline" x-rays, and computed tomography scans to calculate patellar tilt, patellar height, and TT-TG distance. RESULTS: The interobserver agreement was excellent for all parameters (intraclass correlation coefficient >0.95). Preoperatively, the median patellar tilt without quadriceps contraction (QC) was 17.5° (range 5.3°-33.4°) and with QC was 19.8° (range 0°-52.0°). The median Caton-Deschamps index was 0.91 (range 0.80-1.22) and TT-TG distance was 14.5 mm (range 4.0-22.0 mm). Postoperatively, the median patellar tilt without QC was 0.3° (range -15.3° to 9.5°) and with QC was 6.1° (range -11.5° to 13.3°). The median Caton-Deschamps index was 1.11 (range 0.81-1.20) and TT-TG distance was 10.1 mm (range 1.8-13.8 mm). CONCLUSION: The present study demonstrates that beyond replacing arthritic cartilage, trochlear-cutting PFA improves patellofemoral congruence by correcting trochlear dysplasia and standardizing radiological measurements as patellar tilt and TT-TG. The association of lateral patellar facetectomy improves patellar tracking by reducing the patellar tilt.

Chemical and ecotoxicological properties of three bio-oils from pyrolysis of biomasses.

In view of the potential use of pyrolysis-based technologies, it is crucial to understand the environmental hazards of pyrolysis-derived products, in particular bio-oils. Here, three bio-oils were produced from fast pyrolysis of pine wood and intermediate pyrolysis of corn stalk and poultry litter. They were fully characterized by chemical analysis and tested for their biodegradability and their ecotoxicity on the crustacean Daphnia magna and the green alga Raphidocelis subcapitata. These tests were chosen as required by the European REACH regulation. These three bio-oils were biodegradable, with 40-60% of biodegradation after 28 days, and had EC50 values above 100mgL(-1) for the crustacean and above 10mgL(-1) for the alga, showing low toxicity to the aquatic life. The toxic unit approach was applied to verify whether the observed toxicity could be predicted from the data available for the substances detected in the bio-oils. The predicted values largely underestimated the experimental values.

The incidence of fragility fractures in Italy.

Osteoporosis can significantly impact on the risk of developing a fracture. Thus, fragility fractures represent a challenge for health professionals and decision makers of the twenty-first century. The aim of this work is to review the literature concerning osteoporotic fractures in Italy in terms of incidence, rate of hospitalization, relative risk of a new fragility fracture, and costs for the national health system. It was estimated that the costs of treating proximal femur fragility fractures in 2002 summed up to 1 billion Euros. The number of fragility fractures in Italy was calculated as follows: 91.494 hip fractures, 61.009 clinical vertebral fractures, 57.401 humeral fragility fractures, and 94.045 forearm/wrist fragility fractures. The incidence of fragility fractures in Italy is very high, and osteoporosis is the leading cause of morbidity in the Italian population.

XEN Gel Staining with Trypan Blue: A Simple and Effective Technique to Improve Device Visualization during Implantation.

The Xen Gel Stent (Allergan, Irvine, CA, USA) is a hydrophilic collagen-based gelatin tube of 6 mm in length which creates a channel of communication between the anterior chamber and the subconjunctival space allowing aqueous humor outflow. XEN is an ab interno, minimally invasive, glaucoma surgery device which has a better safety profile and offers a less invasive way of lowering intraocular pressure. Unfortunately, one of its weaknesses is that visualization of the implant during surgery is difficult, and this difficulty may be exacerbated, for instance, by a subconjunctival hemorrhage. The purpose of this paper is to describe a simple and effective technique for improving device visualization (XEN 45 µm) during the implantation. How to cite this article: Ramovecchi V, Franco F, Barbera GR. XEN Gel Staining with Trypan Blue: A Simple and Effective Technique to Improve Device Visualization during Implantation. J Curr Glaucoma Pract 2021;15(3):161-163.

Patient and surgeon comfort in vitreoretinal surgery performed with Sub-Tenon's Anaesthesia.

Background. Since Stevens first introduced Sub-Tenon's anaesthesia into cataract surgery it has shown itself to be a safe, simple, and efficient technique. The advantages of this type of block are comparable to those of sharp needle anaesthesia and complications are minimal. Several studies have found that the anaesthesia provided by Sub-Tenon's capsule injection is as good as or better for cataract surgery than that achieved by retrobulbar injection, but the efficacy of Sub-Tenon's block in vitreoretinal surgery is less well established. Methods. We performed 50 vitreoretinal procedures; 50 eyes received a Sub-Tenon's injection of a 5 ml mixture (50:50) of lidocaine and ropivacaine, plus 15 IU mL-1 of Hyaluronidase. Results. In 45 cases, only one injection was needed to achieve sufficient anaesthesia and akinesia; in 5 cases a second injection was performed five minutes after the first. Mean surgical time was 45.7 minutes. After surgery, each patient was asked to indicate his value on the VAS pain scale. Mean VAS degree was 2.4. In 7 cases, VAS was > 3 and the pain was successfully managed with the administration of paracetamol in the postoperative period. No light perception was detected at the end of surgery in 33 patients. All cases with 2 injections had no light perception at the end of surgery. Anaesthesia lasted throughout the surgery in all cases. The surgeon performed all surgery comfortably and with no difficulty. Conclusions. According to our experience and to a growing body of evidence, Sub-Tenon's anaesthesia appears to be a safe, simple, versatile, and effective technique and should be considered as a real alternative method of anaesthesia in vitreoretinal surgery.

Müller-Weiss disease: Four case reports.

BACKGROUND: Müller-Weiss disease (MWD) is an idiopathic foot condition characterized by spontaneous tarsal "scaphoiditis" in adults. Frequently bilateral and affecting females during the 4th-6th decades of life, the pathogenesis of MWD remains unclear: It has been traditionally considered a spontaneous osteonecrosis of the navicular. The typical presentation of MWD is a long period of subtle discomfort followed by prolonged standing, atraumatic, disabling pain. Currently, there is no gold standard for the treatment of patients with MWD. Most support initial conservative therapy. Operative treatment should be considered for failure of conservative therapies longer than 6 months. The indication for surgery is severity of symptoms rather than severity of deformities. Operative treatment options include core decompression, internal fixation of the tarsal navicular, open or arthroscopic triple fusion, talo-navicular or talo-navicular-cuneiform arthrodesis, and navicular excision with reconstruction of the medial column. CASE SUMMARY: In this study, we report four patients affected by MWD. Clinical and radiographic assessment, follow-up and treatment are reported. CONCLUSION: As it is frequently misdiagnosed, MWD is challenging for orthopedic surgeons. Early diagnosis and effective treatment are mandatory to avoid sequelae.

Blood loss in trochanteric fractures: multivariate analysis comparing dynamic hip screw and Gamma nail.

INTRODUCTION: Anaemia in patients with trochanteric fracture is associated with increased morbidity and mortality and it is an independent risk factor for functional mobility of patients. Several authors have reported the blood loss following operative treatment comparing different fixation systems but few authors have evaluated many associated variables that could influence the perioperative blood loss. PURPOSE: To evaluate the blood loss in patients that had their trochanteric fracture stabilized with dynamic hip screw (DHS) or Gamma nail. Multivariate analysis of different variables that can influence blood loss was carried out (type of fracture, antiaggregant or anticoagulant therapy, time to surgery). The hypothesis was that there is no difference in terms of blood loss in patients with trochanteric fracture treated with DHS or Gamma nail considering all these variables. MATERIALS & METHODS: Perioperative blood loss was evaluated in 417 consecutive patients treated for trochanteric fracture with DHS or Gamma nail between January 2010 and March 2013. The perioperative blood loss was calculated using the Lisander formula modified by Foss-Kehlet based on pre- and post-operative haemoglobin values and transfusion rates. Univariate and multivariate analysis were performed integrating the following variables: type of fracture (A1 vs A2), antiaggregant/anticoagulant therapy vs no therapy, time to surgery (<24 vs >24 hours from trauma), type of implant (DHS vs Gamma nail). RESULTS: A significant blood loss (p <0.05) was observed between A1 and A2 fracture types (1247ml vs 1796.7ml), antiaggregant/anticoagulant therapy and no therapy (1592.7ml vs 1470.2ml), time-to-surgery <24 and >24 hours from trauma (1584.4ml vs 1323.9ml), DHS and Gamma nail (894.7ml vs 1720.6ml). At multivariate analysis, in the A1 fracture groups the DHS showed a significant lower blood loss compared to Gamma nail (p < 0.05). CONCLUSIONS: According to the perioperative blood loss, DHS should be used in A1 fractures while Gamma nail can be taking in account for the unstable A2 fractures.

Treatment of unstable osteochondritis dissecans in adults with autogenous osteochondral grafts (Mosaicplasty): long-term results.

PURPOSE: the unstable osteochondritis dissecans (OCD-type II and III according to the ICRS classification) of the knee largher than > 2.5 cm(2) in adults are uncommon lesions and there is no consensus on how to treat them. Medium-term studies have reported good results using autogenous osteochondral plugs (mosaicplasty). The aim of this study is to analyze the long-term results of this technique for the treatment of unstable OCD in a selected group of adult patients. METHODS: four patients with OCD at either one of the femoral condyles were included in this prospective study. The average age was 21.2 years (range, 18-24 years). The OCD lesions were classified as type II in three patients and type III in one patient and the average size was 3.8 cm(2) (range, 2.55-5.1 cm(2)). The lesions were treated in situ with a variable number of autogenous osteochondral plugs (Ø 4.5 mm(2)). The Modified Cincinnati, Lysholm II and Tegner scores were used for clinical and functional evaluation. Magnetic resonance arthrography (MRA) was performed before surgery and at 2, 5 and 10 years after surgery. A modified MOCART score was used to evaluate MRA findings. RESULTS: the average follow-up duration was ten years and 6 months (range, 10-11 years). No complications occurred. At the final follow-up, all scores (clinical, functional and MOCART) improved. In all but one of the patients MRA showed complete osteochondral repair. CONCLUSIONS: the fixation of large and unstable OCD lesions with mosaicplasty may be a good option for treating type II or III OCD lesions in adults. The advantages of this technique include stable fixation, promotion of blood supply to the base of the OCD fragment, and grafting of autologous cancellous bone that stimulates healing with preservation of the articular surface. LEVEL OF EVIDENCE: Level IV, therapeutic case series.