Survival Analysis and Failure Modes of Total Hip Arthroplasty Using a Cemented Semi-Retentive Acetabular Cup.

To reduce the incidence of total hip revisions, there have been continuous efforts to enhance prosthetic materials and designs to optimize implant survival. A primary implant with a constrained acetabular component is often used to minimize the risk of dislocations even though this approach has some drawbacks as reported in the literature. To address these concerns, this study aimed to assess the survivorship and dislocation rate of a semi-retentive cemented acetabular cup when used as a primary implant. The specific cemented cup that we studied was not present in any study that we consulted, so to fill this gap, we conducted a retrospective examination of 527 cemented hip prostheses that utilized the semi-retentive cup between the years 2005 and 2012. We employed Cox multiple regression models for our statistical analysis. The revision due to dislocation occurred in 12.8% of all cases, with a lower incidence of 5% (14 cases) in age groups >70 years than in age groups <70 years (14%-32 cases) (p < 0.001). The survival rates of the semi-retentive cemented acetabular cup were 98.6% (520 cases) at 5 years and 92.2% (487 cases) at 10 years. The survival rates were significantly lower in women than men, with 1.9% (7 cases) toward 0% at 5 years and 8.1% (30 cases) toward 5% (7 cases) at 10 years (p = 0.002). The difference in failure rates between age groups over 70 years (2.3%-10 cases) and age groups under 70 years (11.5%-34 cases) was also statistically significant (p < 0.001). Our study indicates that the semi-constrained design may cause frequent damage to the polyethylene liner due to impingement and wear, which are the primary factors for failure. Also, this implant has a similar risk of revision due to dislocation as reported in studies and may be beneficial as a primary implant in elderly patients with low-demanding lifestyles, muscular insufficiency, and low compliance regarding hip prosthetic behavior, without a major effect on survivorship.

The Role of Fascial Tissue Layer in Electric Signal Transmission from the Forearm Musculature to the Cutaneous Layer as a Possibility for Increased Signal Strength in Myoelectric Forearm Exoprosthesis Development.

Myoelectric exoprostheses serve to aid in the everyday activities of patients with forearm or hand amputations. While electrical signals are known key factors controlling exoprosthesis, little is known about how we can improve their transmission strength from the forearm muscles as to obtain better sEMG. The purpose of this study is to evaluate the role of the forearm fascial layer in transmitting myoelectrical current. We examined the sEMG signals in three individual muscles, each from six healthy forearms (Group 1) and six amputation stumps (Group 2), along with their complete biometric characteristics. Following the tests, one patient underwent a circumferential osteoneuromuscular stump revision surgery (CONM) that also involved partial removal of fascia and subcutaneous fat in the amputation stump, with re-testing after complete healing. In group 1, we obtained a stronger sEMG signal than in Group 2. In the CONM case, after surgery, the patient's data suggest that the removal of fascia, alongside the fibrotic and subcutaneous fat tissue, generates a stronger sEMG signal. Therefore, a reduction in the fascial layer, especially if accompanied by a reduction of the subcutaneous fat layer may prove significant for improving the strength of sEMG signals used in the control of modern exoprosthetics.

Irreducible Knee Dislocation With Vastus Medialis Muscle Interposition: A Case Report.

Irreducible knee dislocation (KD) is a rare high-velocity injury (determined by shear and/or rotational forces) that is associated with the interposition of capsule-ligamentous or muscle structures in the joint space. This condition often requires open reduction. To our knowledge, irreducible KD is not widely reported in the literature. Here, we report the case of a 69-year-old man with a right KD that occurred after falling from a height and entrapment of the leg between concrete blocks. The patient presented to the emergency department with a right knee deformity without distal neurovascular deficit. After two failed attempts of close reduction (under sedation and spinal anesthesia), open reduction was performed. Intraoperatively, there were cruciate ligament tears, wide capsule tears, and intra-articular vastus medialis interposition, preventing reduction. The decision to release the muscle from the notch, suture of the medial capsule, temporary K-wire stabilization, and cast immobilization were taken. After K-wire removal, the patient underwent rehabilitation to regain function and resume activities of daily living. This case report highlights the need for open reduction in some KD cases. Identifying possible soft-tissue interposition can accelerate surgical treatment and minimize the risk of complications.

Oncologic Outcome after Pulmonary Metastasectomy as Part of Multidisciplinary Treatment in a Tertiary Oncological Center.

(1) Background: Pulmonary metastases are encountered in approximately one-third of patients with malignancies, especially from colorectal, lung, breast, and renal cancers, and sarcomas. Pulmonary metastasectomy is the ablative approach of choice, when possible, as part of the multidisciplinary effort to integrate and personalize the oncological treatment. (2) Methods: The study includes 58 consecutive cases of pulmonary metastasectomies, retrospectively analyzed, performed in 12 consecutive months, in which the pathology reports confirmed lung metastases. (3) Results: Most frequent pathological types of metastases were: 14 of colorectal cancer, 10 breast, 8 lung, and 8 sarcomas. At the time of primary cancer diagnosis, 14 patients (24.14%) were in the metastatic stage. The surgical approach was minimally invasive through uniportal VATS (Video-Assisted Thoracic Surgery) in 3/4 of cases (43 patients, 74%). Almost 20% of resections were typical (lobectomy, segmentectomy). Lymphadenectomy was associated in almost 1/2 of patients and lymph node metastases were found in 11.11% of cases. The mortality rate (intraoperative and 90 days postoperative) is zero. The OS after pulmonary metastasectomy is 87% at 18 months, and the estimated OS for cancer is 90% at 5 years. The worst outcome presents the patients with sarcomas and the best outcome-colorectal and lung cancer. The patients with 1 or 2 resected metastases presented 96% survival at 24 months. (4) Conclusions: After pulmonary metastasectomy, survival is favored by the small number of metastases resected (1 or 2), and by the dimension of metastases under 20.5 mm. The non-anatomic (wedge) type of lung resection may present a lower risk of death compared to lobectomy. No statistical significance on survival has the presence of lymphadenectomy, the laterality right/left lung, the upper/lower lobes. In the future, longer follow-up and prospective randomized trials are needed for drawing definitive conclusions.

Transfemoral Approach in Revision Hip Arthroplasty: A Prospective Analysis of 36 Cases: Radiological and Functional Results at a Minimum 2 Years Follow-up.

Background and Objectives: One of the most difficult aspects of hip revision is to remove the stem from the femoral canal with or without cement while maintaining the maximal amount of bone stock to obtain the best possible press-fit of the revision prosthesis. The transfemoral approach ensures direct access to the medullary canal so that the content removal is completed under direct control, while protecting the bone. This type of approach is particularly efficient for special conditions, such as deformation of the proximal femoral region, broken stems, or the presence of cement over a long distance distal to the prosthesis. The aim of this study was to evaluate the main advantages of transtrochanteric approach in hip revisions. Materials and Methods: Our series included 36 revisions performed using the transfemoral approach. We have analyzed the following postoperative radiological aspects: the length of the fixation zone distal to the osteotomized bone fragment (OBF), the gap between the OBF and the diaphysis, stem subsidence over time, and OBF consolidation. Results: The results were very good, both in terms of the rate of intraoperative complications and postoperative evolution. The fixation zone length was 4.2 cm on average (range: 2 to 5.8 cm). The distal gap between the OBF and the diaphysis was 1.2 cm on average (range: 0 to 2.3 cm). Stem subsidence was noted in four cases (11.1%). In all cases, stem subsidence occurred between three and six months and was 6 to 8 mm without affecting hip stability. OBF consolidation was radiologically confirmed for all cases at one year follow-up. Clinical assessment based on the Harris Hip Score showed an overall improvement from 43.2 preoperatively to 79.7 at 12 months and 83 at two years, respectively. The most important rate of progress was between 6 months and 12 months. Conclusions: The transtrochanteric approach has been shown to be very efficient for hip revisions. Understanding the hip biomechanics, applying a less aggressive surgical technique, and using efficient fixation methods such as cables significantly improved the results.

A finite element analysis for predicting outcomes of cemented total knee arthroplasty.

The study was designed to assess the validity of a finite element analysis for predicting the behavior of cemented knee implant used in total knee arthroplasty (TKA), for different mechanical loads, and correlation with clinical outcomes of this procedure. We conducted computational simulations using finite element analysis of two situations: i) The ideal prosthetic component positioning; and ii) variable varus tibial malposition, but with a balanced knee. A total of 80 cemented TKAs performed on 70 patients were divided into two groups. Patients from one group required secondary asymmetric tibial recut for balancing the prosthetic knee and patients from the other group, did not. In regards to the results, we observed no differences upon analysis of the postoperative results of the Knee Society Score (KSS), the angle between the femur and tibia, the range of motion and frontal laxity between groups. The finite element analysis showed that in a 3˚ varus inclination of the joint interline, but with a balanced knee, the maximum contact stress, measured on the tibial plateau surface, increased by 11% compared to the value of mechanical alignment. In conclusion, analysis of the computational model using finite elements showed predictable results of cemented TKA for the different situations of mechanical loads.

Giant Cell Tumor of Long Bones Outcomes of Treatment Corelating with Histopathological Grade.

INTRODUCTION: Giant cell tumor (GCT) of bone is a borderline lesion of bones, meaning that in certain conditions it could be transforming in malignant tumor. This article describes the clinical outcome of patients with giant cell tumor of bone and discusses the surgical options for this lesion corelating with histopathological grade. MATERIAL AND METHODS: From 2007 to 2015, 15 patients who met the histological criteria of giant cell tumor of bone were treated at our institution. Diagnosis and histopathological grade were established by biopsy and extemporaneous exam during surgery. Procedure to be selected was decided based on histopathological grade. Outcomes: In all cases the joint functional results were good except 3 cases (20%) where recurrence occurred. In one case the local recurrence was observed after 6 months, and in the other 2 cases, at 3, respectively 5 years after primary treatment. In all 3 cases the initial histopathological exam showed inactive lesions and were treated with curettage and bone grafting. CONCLUSION: In our series it was an early reccurence at 6 months and 2 recidives after 2 years.The histopathological exam has significant role in the management of GCT. All inactive lesions were treated by curettage and bone grafting, and active lesions, by curettage and bone cement filling no matter of Campanacci's grading system. The management is depending mostly on histopathological exam. Low rate of recurrence can be achieved if treatment is selected according to this parameter and with a properly technique.