An Innovative Method to Analyse the Geometrical Accuracy of Ti6Al4V Octet-Truss Lattice Structures.

Metal lattice structures manufactured utilising additive techniques are attracting increasing attention thanks to the high structural efficiency they can offer. Although many studies exist on the characterisation of massive parts in Ti6Al4V processed by Electron Beam Melting (EBM), several investigations are necessary to characterise the Ti6Al4V lattice structures made by the EBM process. The objective of this paper is to develop a measurement method to assess the dimensional accuracy of Ti6Al4V octet truss lattice structures manufactured by EBM technology. Beam specimens with a 2 mm diameter and different growth orientations with respect to the build direction were analysed. The geometry differences between the designed and the manufactured beam specimens were highlighted. Two effects were identified: (i) The EBM-manufactured beams are generally thinner than the designed ones, and (ii) the shape of the section was found to be almost circular for the beam specimens oriented at 45° and 90°; on the contrary, the section of the horizontal beam (0°) cannot be considered circular.

Interposition Arthroplasty in the Treatment of End-Stage Hallux Rigidus: A Systematic Review.

PURPOSE: Patients affected by moderate to severe hallux rigidus may opt for interposition arthroplasty to avoid the movement restrictions of arthrodesis and the complications related to prosthetic replacement. The propose of this article was to review the current literature about interposition arthroplasty to examine the overall outcomes and to evaluate the advantages and disadvantages of different types of technique, compared with more consolidated procedures. METHODS: A literature PubMed search was performed. Studies reporting the results of interposition arthroplasty in moderate to severe hallux rigidus were included. The data were pooled and weighted for number of patients in every study. RESULTS: The overall results for interposition arthroplasties are comparable to other alternatives for end-stage hallux rigidus, providing better plantar load distribution than arthrodesis and avoiding the drawbacks of prosthetic replacement. Among the various interposition arthroplasty techniques, the Modified Oblique Keller Capsular Interposition Arthroplasty technique preserves toe length and flexor hallucis brevis function, showing the highest satisfaction rate, with lowest metatarsalgia and revision rate. CONCLUSION: Although long-term randomized controlled trials are lacking for interposition arthroplasty, it represents a valid alternative for the treatment of end-stage hallux rigidus also in the young active patient who wants to avoid a definitive intervention immediately. LEVEL OF EVIDENCE: III (systematic review of level III-IV-V studies).

Hallux rigidus: current concepts review and treatment algorithm with special focus on interposition arthroplasty.

BACKGROUND AND AIM OF THE WORK: Hallux rigidus represents a surgical challenge, with a multitude of possible surgical options, but with no ideal procedures.  The propose of this paper was to review the actual knowledge on the operative techniques, paying particular attention to the evolution of interposition arthroplasties, as an alternative to arthrodesis and prosthesis in the advanced stages of the disease. METHODS: A comprehensive literature PubMed search was performed, and the actual literature regarding hallux rigidus was overviewed. The operative and nonoperative options for HR were described. Studies on interposition arthroplasty were classified by publication year, summarizing the operative technique, results and complications. RESULTS: Among the various techniques for interposition arthroplasty, the Modified Oblique Keller Interposition Arthtoplasty (MOKCIA) showed the lower complication rate. It does not sacrifice the insertion of the flexor halluces brevis, maintaining the stability, length and strength of the big toe. CONCLUSIONS: Although long-term randomized controlled trials are lacking for interposition arthroplasties, the reported results are comparable to the other alternatives for the treatment of end-stage hallux rigidus, making this technique a valid alternative also in the young active patient, without precluding other end-stage procedures in case of failure. Based on the current knowledge, a treatment algorithm was developed, according to the Coughlin classification.

Quadriceps or patellar ligament reconstruction with artificial ligament after total knee replacement.

BACKGROUND AND AIM OF THE WORK: Ruptures of the quadriceps or patellar tendon after TKA implantation are a fearful and disabling complication. Direct reconstructions highlighted various problems, such as the decrease in extensor force, failure, need for prolonged post-operative immobilization. So augmentation techniques have been proposed with autologous tendons, allografts, artificial ligaments. Among these, the LARS seems the most modern and promising. For this reason, we have retrospectively reviewed a case series patients operated with this artificial ligament, to evaluate the results and highlight the tips and tricks for this procedure. METHODS: Ten patients with a mean age of 69.4 years suffered an extensor apparatus lesion after knee replacement. These patients underwent primary reconstruction and augmentation with LARS. They were retrospectively reviewed at a mean follow-up of 3.8 years, by measuring active flexion and extension, and by Lysholm scoring scale. RESULTS: We did not observe any problems with healing of the surgical wound, nor phenomena of intolerance to the implanted material, such as inflammation, skin rashes or fistulas. The mean flexion was 117 degrees. Active extension was allowed in all patients, but with a mean extensor lag of 18 degrees. The mean Lysholm score was 74.2. CONCLUSIONS: LARS offers good results without completely solving the problem of extensor lag, linked to the softness of the tissues in the quadriceps. The major advantages of LARS reside in the good tissue ingrowth, the absence of adverse tissue reactions, the ubiquitous availability, the possibility of stable fixation with early rehabilitation.

Anterior and antero-lateral mini-invasive approaches for primary total hip replacement.

BACKGROUND AND AIM OF THE WORK: the literature provides conflicting data regarding the various approaches for hip prosthetic surgery. This study analysed our case series on the anterior and anterolateral minimally invasive approaches, trying to define the indications, complications, the technical tips, the advantages and disadvantages. METHODS: from 2011 to 2019 we performed 1227 interventions of which 1020 had a regular follow-up, up to an average period of 5.1 years. 625 anterolateral and 395 anterior approaches were performed, of which 149 with longitudinal incision and 246 with an oblique "bikini" incision. RESULTS: the Harris Hip Score showed similar results in the two groups, except from the early post-operative period, which showed slight superior results for the anterior approach. Surgical times were in favour of the anterolateral approach, while hospitalization times were less for the anterior approach. With the anterior approach, we recorded a greater number of complications, in particular malpositioning, periprosthetic fractures and neurological injuries, especially in the first two years of experience. CONCLUSIONS: there was no clear superiority of one approach over another. We conclude that the surgeon should know both techniques, to be adapted to the type of patient in consideration of the size and deformity. The traction bed provides more disadvantages than advantages, and in our experience it is not recommended.

Dynamic Pulse Buckling of Composite Stanchions in the Sub-Cargo Floor Area of a Civil Regional Aircraft.

This work is focused on the investigation of the structural behavior of a composite floor beam, located in the cargo zone of a civil aircraft, subjected to cyclical low-frequency compressive loads with different amplitudes. In the first stage, the numerical models able to correctly simulate the investigated phenomenon have been defined. Different analyses have been performed, aimed to an exhaustive evaluation of the structural behavior of the test article. In particular, implicit and explicit analyses have been considered to preliminary assess the capabilities of the numerical model. Then, explicit non-linear analyses under time-dependent loads have been considered, to predict the behavior of the composite structure under cyclic loading conditions. According to the present investigation, low-frequency cyclic loads with peak values lower than the static buckling load value are not capable of triggering significant instability.

Five Centimeters Morton's Neuroma in a 46-Year-Old Woman Affected by Macrodactily.

The present article described the case of a voluminous Morton's neuroma of the third intermetatarsal space in a patient affected by macrodactily. The case was unique because of its dimensions, the uncommon surgical approach which was needed for removal, the association with macrodactily of the fourth toe with Raynaud's phenomenon, and the postoperative defect in the intrinsic muscles. The patient was operated in February 2016 by transverse plantar approach. Twelve months after surgery, the patient complained for hypoesthesia on third and fourth toes with inability to actively spread the toes and enlargement in the second interdigital space. The dimensions of the lesions may be explained with the presence of macrodactily in the fourth toe with occasional Raynaud's phenomenon, which may have caused an abnormal arrangement of the nerve branches for the fourth interspace with related microtrauma. A plantar approach was highly recommended as the size of the lesion forced it to the plantar surface of the foot. The inability to actively spread the toes and the enlargement of the second interdigital space are likely to be related to a deficiency of the interosseous muscles, innervated by the deep branch of the lateral plantar nerve, which had probably been sacrificed because of the size of the lesion and the subversion of the surrounding anatomical relationships.

Current concepts about treatment options of plantar fibromatosis: A systematic review of the literature.

BACKGROUND: Plantar fibromatosis, or Ledderhose disease, is a benign and hyperproliferative disease of the plantar aponeurosis. There have been described different therapeutic options regarding plantar fibromatosis, both conservative and surgical. The aim of this review is to systematically analyze conservative and operative treatments of plantar fibromatosis described in literature, evaluating which procedure shows the highest success rate and best functional outcome. METHODS: A systematic review of PubMed, Google Scholar and Cochrane reviews computerized database was performed focusing on the different types of treatments for plantar fibromatosis. Research was performed using the keywords "plantar", "fibromatosis", "Ledderhose", "Dupuytren", "foot" in order to identify all papers regarding the treatment of plantar fibromatosis. In addition, the research was extended to the reference list of the relevant articles. A total of 25 citations were obtained from the research and included. RESULTS: Considering all the studies, 233 patients were included in this systematic review. 5 studies reported conservative treatment of plantar fibromatosis, with a total of 35 patients included. Operative outcomes are reported for 178 patients (92 male, 86 female), with 196 feet treated. CONCLUSIONS: Valid conservative methods are presented in literature, with debated results. Some operative options show high recurrence rate; wide excision is recommended in selected cases. Further clinical trials with well-defined and standardized outcome measurements should be necessary in future to better evaluate success rate and complications of the various procedures.

Morton's interdigital neuroma of the foot: A literature review.

Morton's neuroma is one of the most common causes of metatarsalgia. Despite this, it remains little studied, as the diagnosis is clinical with no reliable instrumental diagnostics, and each study may deal with incorrect diagnosis or inappropriate treatment, which are difficult to verify. The present literature review crosses all key points, from diagnosis to surgical and nonoperative treatment, and recurrences. Nonoperative treatment is successful in a limited percentage of cases, but it can be adequate in those who want to delay or avoid surgery. Dorsal or plantar approaches were described for surgical treatment, both with strengths and weaknesses that will be scanned. Failures are related to wrong diagnosis, wrong interspace, failure to divide the transverse metatarsal ligament, too distal resection of common plantar digital nerve, an association of tarsal tunnel syndrome and incomplete removal. A deep knowledge of the causes and presentation of failures is needed to surgically face recurrences.

Postarthroscopy Osteonecrosis of the Knee: Current Concepts.

Knee osteonecrosis is a severe disease rapidly leading to end-stage osteoarthritis, which was classified into three categories: spontaneous, secondary, and postarthroscopy. To understand postarthroscopy osteonecrosis of the knee, all the three types of knee osteonecrosis have to be deepened. This article reviewed spontaneous and secondary osteonecroses of the knee, with special focus upon postarthroscopy osteonecrosis, which is a rare form, affecting patients operated for arthroscopic knee surgery, most commonly for meniscectomy. Due to its rarity, patients and surgeons are often unprepared for this complication. A correct diagnosis is essential for appropriate treatment, and also to determine if a preexisting osteonecrosis was present, avoiding medicolegal sequelae, although many authors agree that osteonecrosis (both spontaneous and postarthroscopy) represent unpreventable and unpredictable conditions. In spontaneous osteonecrosis, the treatment is defined according to the size and the degree of the lesion, whereas in postarthroscopy osteonecrosis, the size of the lesion has no prognostic value, and therefore, the choice of the correct treatment is based more on the timing of the diagnosis. A diagnostic and therapeutic algorithm was outlined on the basis of the actual knowledge.

Cementless knee arthroplasty.

Total knee replacement is a common treatment for advanced knee osteoarthritis. The most common and widespread method is cemented arthroplasty. As in the prosthetic hip a gradual transition from cemented to uncemented fixation techniques occurred over time, increasing interest is growing also around cementless knee fixation, with the theoretical advantages of preserving the bone stock and obtaining a biological fixation avoiding cement fragmentation. On the basis of the actual knowledge, the uncemented knee prosthesis represents an interesting alternative especially for the patient under 65 years of age, with viable bone quality, in which a biological bone-prosthesis fixation is desirable, while avoiding the drawbacks of cement fragmentation and of the possible future revision of a cemented implant. However the weak link remains the tibial fixation, so that technical tips are important to avoid micromovements with subsequent lack of osteointegration. In our experience, gap balancing, mobile bearings and no haemostatic tourniquet well combine with this kind of implant.

Posterior ankle impingement.

Posterior ankle impingement is a common cause of chronic ankle pain and results from compression of bony or soft tissue structures during ankle plantar flexion. Bony impingement is most commonly related to an os trigonum or prominent trigonal process. Posteromedial soft tissue impingement generally arises from an inversion injury, with compression of the posterior tibiotalar ligament between the medial malleolus and talus. Posterolateral soft tissue impingement is caused by an accessory ligament, the posterior intermalleolar ligament, which spans the posterior ankle between the posterior tibiofibular and posterior talofibular ligaments. Finally, anomalous muscles have also been described as a cause of posterior impingement.

Foot overuse diseases in rock climbing: an epidemiologic study.

BACKGROUND: Literature examining the incidence of foot diseases in rock climbing is limited to traumatic injuries. We examined a large sample of climbers, assessed the chronic diseases of the foot, and correlated them with foot morphology, shoe type, and type of climbing practiced. METHODS: Between May 1 and September 30, 2009, 144 climbers (mean age, 31.7 years) were examined to analyze the effect of rock climbing on the various foot diseases found at the time of the evaluation. RESULTS: Eighty-six percent of the climbers were affected by a pathologic condition. Nail disease was found in 65.3% of patients, followed by recurrent ankle sprains (27.8%), retrocalcaneal bursitis (19.4%), Achilles tendinitis (12.5%), metatarsalgia (12.5%), and plantar fasciitis (5.6%). Male sex, the use of high-type shoes, the high degree of climbing difficulty, and the competitive level were often related to the onset of foot diseases. Climbing shoes are usually smaller than common footwear. This "shoe-size reduction" averaged 2.3 sizes, forcing the foot into a supinated and cavus posture that favors lateral instability. The posterior edge of the shoe aperture produces increased pressure on the heel, with retrocalcaneal bursitis. CONCLUSIONS: Overuse foot diseases related to rock climbing are particularly frequent and debilitating. Detailed knowledge of these diseases and their predisposing factors may help us implement effective preventive or therapeutic measures, including changes in the type of climbing, correction of body weight, degree of difficulty, footwear, orthoses, and measures that maximize the support of the foot to the ground.

Allograft salvage procedure in multiple-revision anterior cruciate ligament reconstruction.

BACKGROUND: Multiple-revision anterior cruciate ligament (ACL) reconstructions represent a surgical challenge due to the presence of previous tunnels, hardware, injuries to the secondary stabilizers, and difficulties in retrieving autologous tendons. An anatomic ACL reconstruction may therefore result in a demanding surgery, thus requiring 2 stages. PURPOSE: To analyze the efficacy of an over-the-top ACL reconstruction technique plus extra-articular plasty using Achilles or tibialis posterior tendon allograft in restoring knee stability in patients with at least 2 failed previous ACL reconstructions, as well as to evaluate the factors able to affect the final outcome. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: From 2002 to 2008, 24 male athletes with a mean age of 30.8 years underwent surgery. Twenty patients had undergone 2, whereas 4 patients had undergone 3 previous reconstructions. The International Knee Documentation Committee (IKDC) score and KT-2000 arthrometric evaluation were used to measure outcomes at a mean follow-up period of 3.3 years (range, 2-7). RESULTS: The mean ± SD IKDC subjective score at follow-up was 81.3 ± 14.0. The IKDC objective score was an A or B in 20 patients (83%). Arthrometer side-to-side difference averaged 3.1 ± 1.1 mm. Range of motion was normal or nearly normal in 23 patients and abnormal in 1. Of the 20 good results, 17 patients resumed sports activity at the preinjury level. CONCLUSION: A 2-stage revision is an accepted option in cases of excessive tunnel enlargement and bone loss, especially on the femoral side, to achieve anatomic reconstruction. Nonanatomic over-the-top ACL reconstruction and lateral extra-articular plasty technique allow one to overcome difficult anatomic situations on the femoral side, permitting a 1-step surgery. The overall results obtained in this series are comparable with those of other ACL revision series. The higher rate of mild instability observed in our series may not be attributable to the surgical technique but rather to the chronic instability suffered by these knees before last revision.

Bipolar fresh osteochondral allograft of the ankle.

BACKGROUND: Severe post-traumatic ankle arthritis poses a reconstructive challenge in the young and active patient. Bipolar fresh osteochondral allograft (BFOA) may represent an intriguing alternative to arthrodesis and prosthetic replacement. The aim of this study was to describe a lateral trans-malleolar technique for BFOA, and to evaluate the results in a case series. MATERIALS AND METHODS: From 2004 to 2006, 32 patients, mean age of 36.8 +/- 8.4 years, affected by ankle arthritis underwent BFOA with a mean followup of 31.2 months. The graft was prepared by specifically designed jigs, including the talus and the tibia with the medial malleolus. The host surfaces were prepared by the same jigs through a lateral approach. The graft was placed and fixed with twist-off screws. Patients were evaluated clinically and radiographically at 2, 4, and 6 month after operation, and at a minimum 24 months followup. A biopsy of the grafted areas was obtained from 7 patients at 1-year followup for histological and immunohistochemical examination. RESULTS: Preoperative AOFAS score was 33.1 +/- 10.9 and postoperatively 69.5 +/- 19.4 (p < 0.0005). Six failures occurred. Cartilage harvests showed hyaline-like histology with a normal collagen component but low proteoglycan presence and a disorganized structure. Samples were positive for MMP-1, MMP-13 and Capsase-3. CONCLUSION: The use of BFOA represents an intriguing alternative to arthrodesis or arthroplasty. We believe precise allograft sizing, stable fitting and fixation and delayed weightbearing were key factors for a successful outcome. Further research regarding the immunological behavior of transplanted cartilage is needed.

Foot and lower limb diseases in runners: assessment of risk factors.

The present study analyzed the impact of the running style and the morphologic and functional characteristics of the foot on the incidence of non-traumatic foot and lower limb disorders in runners. From January 2004 to December 2008, we prospectively examined 166 runners, both recreational and competitive, involved in various running specialities, from three athletics clubs in Northern Italy. They were 86 males and 80 females, with a mean age of 31.1 ± 12.2 years. We considered non-traumatic foot and lower limb diseases reported during the follow-up period, which resulted in a minimum sport rest of two weeks. The incidence of these diseases was examined with respect to general characteristics, type of activity, foot morphology, running style. 59% of athletes reported one or more diseases. The most common were plantar fasciitis (31% of athletes) and Achilles tendinopathies (24%). Overall, the more prone to injuries were males (60.9% of cases), competitive runners (70.9%), middle-distance runners (51.7%), and those using spike shoes (80.3%). Age, body weight and height were not important predictors of running injuries in general. Considering the morphological characteristics of the foot, the most prone to injury were the varus hindfoot (87.5% of cases) and the cavus arch (71.4%). In conclusion, a deep knowledge of the factors predisposing runners to specific diseases, often chronic and highly debilitating for the athlete, may allow implementing effective therapeutic measures. Key pointsExamination of 166 runners during a period of five years of activity.The incidence of these diseases was examined with respect to general characteristics, type of activity, foot morphology, running style.59% of athletes reported one or more diseases. The most common were plantar fascitis (31% of athletes) and Achilles tendinopathies (24%).Overall, the more prone to injuries were males (60.9% of cases), competitive runners (70.9%), middle-distance runners (51.7%), and those using spike shoes (80.3%).Age, body weight and height were not important predictors of running injuries in general.The most prone to injury were the varus hindfoot (87.5% of cases) and the cavus arch (71.4%).

Arthroscopic autologous chondrocyte implantation in osteochondral lesions of the talus: surgical technique and results.

BACKGROUND: Autologous chondrocyte implantation (ACI) in the ankle was considered up to now an extremely technically demanding surgery with considerable morbidity for the patients. HYPOTHESIS: Hyalograft C scaffold allows arthroscopic ACI, thanks to a specifically designed instrumentation. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Forty-six patients with a mean age of 31.4 years (range, 20-47) underwent operation from 2001 to 2004. They had posttraumatic talar dome lesions, type II or IIA. In the first step of surgery, an ankle arthroscopy was performed, with cartilage harvest from the detached osteochondral fragment or from the margins of the lesion. Chondrocytes were cultured on a Hyalograft C scaffold. In the second step of surgery, the Hyalograft C patch was arthroscopically implanted into the lesion, with a specifically designed instrumentation. Lesions >5 mm deep were first filled with autologous cancellous bone. Patients were evaluated clinically with the American Orthopaedic Foot and Ankle Society (AOFAS) score preoperatively and at 12 and 36 months after surgery. At a mean time interval of 18 months, the first 3 patients underwent a second-look arthroscopy with cartilage harvest from the implant and histological examination. RESULTS: The mean preoperative AOFAS score was 57.2 +/- 14.3. At the 12-month follow-up, the mean AOFAS score was 86.8 +/- 13.4 (P < .0005), while at 36 months after surgery, the mean score was 89.5 +/- 13.4 (P < .0005). Clinical results were significantly related to the age of patients and to previous operations for cartilage repair. The results of the histological examinations revealed hyaline-like cartilage regeneration. CONCLUSIONS: The Hyalograft C scaffold and the specifically designed instrumentation allowed arthroscopic implantation of chondrocytes, with excellent clinical and histological results.

Effects of freezing on the biomechanical and structural properties of human posterior tibial tendons.

This work analyzes the effects of storage by fresh-freezing at -80 degrees C on the histological, structural and biomechanical properties of the human posterior tibial tendon (PTT), used for ACL reconstruction. Twenty-two PTTs were harvested from eleven donors. For each donor one tendon was frozen at -80 degrees C and thawed in physiological solution at 37 degrees C, and the other was tested without freezing (control). Transmission electron microscopy (TEM), differential scanning calorimetry (DSC) and biomechanical analysis were performed. We found the following mean changes in frozen-thawed tendons compared to controls: TEM showed an increase in the mean diameter of collagen fibrils and in fibril non-occupation mean ratio, while the mean number of fibrils decreased; DSC showed a decrease in mean denaturation temperature and denaturation enthalpy. Biomechanical analysis showed a decrease in ultimate load and ultimate stress, an increase in stiffness and a decrease in ultimate strain of tendons. In conclusion fresh-freezing brings about significant changes in the biomechanical and structural properties of the human PTT. A high variability exists in the biophysical properties of tendons among individuals and in the effects of storage on tendons. Therefore, when choosing an allograft tendon, particular care is needed to choose a biomechanically suitable graft.