Effects of hexagonal boron nitride on mechanical properties of bone cement (Polymethylmethacrylate).

OBJECTIVES: The aim of this study was to investigate the effects of adding hexagonal boron nitride at four different concentrations to polymethylmethacrylate (PMMA) bone cement, which is commonly used in orthopedic surgeries, on the mechanical properties and microarchitecture of the bone cement. MATERIALS AND METHODS: The study included an unaltered control group and groups containing four different concentrations (40 g of bone cement with 0.5 g, 1 g, 1.5 g, 2 g) of hexagonal boron nitride. The samples used for mechanical tests were prepared at 20±2ºC in operating room conditions, using molds in accordance with the test standards. As a result of the tests, the pressure values at which the samples deformed were determined from the load-deformation graphs, and the megapascal (MPa) values at which the samples exhibited strength were calculated. RESULTS: The samples with 0.5 g boron added to the bone cement had significantly increased mechanical strength, particularly in the compression test. In the group where 2 g boron was added, it was noted that, compared to the other groups, the strength pressure decreased and the porosity increased. The porosity did not change particularly in the group where 0.5 g boron was added. CONCLUSION: Our study results demonstrate that adding hexagonal boron nitride (HBN) to bone cement at a low concentration (0.5 g / 40 g PPMA) significantly increases the mechanical strength in terms of MPa (compression forces) without adversely affecting porosity. However, the incorporation of HBN at higher concentrations increases porosity, thereby compromising the biomechanical properties of the bone cement, as evidenced by the negative impact on compression and four-point bending tests. Boron-based products have gained increased utilization in the medical field, and HBN is emerging as a promising chemical compound, steadily growing in significance.

Does medullary diameter to stem width ratio and stem length affect outcomes of revision total knee arthroplasties? A case series.

OBJECTIVES: This study aimed to investigate the relationship between the ratio of stem size to intramedullary canal diameter, stem length, and functional outcome in revision total knee arthroplasty (RTKA) procedures, which remains largely unexplored in the current literature. PATIENTS AND METHODS: A single surgeon series of RTKA procedures performed between October 2014 and November 2022 were included in this case series, and data were analyzed retrospectively. A total of 32 patients (27 females, 5 males; mean age: 73.2±8.1 years; range, 52 to 88 years) were identified, with a minimum follow-up period of five months and a maximum of eight years. Filtering the patients based on >24 month follow-up, we were left with 13 patients aged between 65 and 88 (mean 74.9±6.9) years. The latest X-rays of patients were analyzed, and the ratio of intramedullary canal diameter to stem width was calculated for both femur and tibia in both anteroposterior and lateral planes. Household income, preoperative C-reactive protein, erythrocyte sedimentation rate, comorbidities, body mass index, and implant dimensions were also recorded. Postoperative Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Short Form-12 (SF-12) scores, and range of motion (ROM) measurements were used to evaluate functional outcome. RESULTS: A moderate negative relationship between the tibial canal fill ratio (CFR) in anteroposterior views and ROM of the patients was noted. Additionally, a significant positive correlation was found between SF-12 physical score and CFR in lateral view. A moderate level of correlation between femoral CFR in anteroposterior views was also established. Due to insufficient data, joint ROM data did not show normal distribution. Therefore, a cutoff value indicating the relationship between the stem size and knee ROM could not be calculated using receiver operating characteristic analysis. Multiple regression analysis did not yield significant results, suggesting that hypothesized predictor variables were not sufficient to predict the variation in functional scores. Otherwise, no clear statistical importance or correlation between functional scores, such as WOMAC or SF-12, and CFR was found. CONCLUSION: In conclusion, the findings suggest that other factors, such as other patient characteristics, surgical techniques, or implant designs, may have a more substantial impact on the functional outcomes in RTKA patients.

Radiographic assessment of bone tunnels after anterior cruciate ligament reconstruction: A comparison of hamstring tendon and bone-patellar tendon-bone autografting technique.

OBJECTIVES: This study aims to compare the postoperative change of femoral and tibial tunnel widths after hamstring tendon (HT) and bone-patellar tendon-bone (BPTB) autografting in primary anterior cruciate ligament (ACL) reconstruction surgery with the anteromedial portal technique. PATIENTS AND METHODS: This case-control and retrospective study included 39 patients (36 males, 3 females; mean age 30.1±7.9; range, 17 to 44 years) who underwent primary ACL reconstruction surgery with either BPTB autografting method (BPTB group, n=18) or HT autografting method (HT group, n=21) between March 2014 and December 2016. Femoral fixation was achieved with bioabsorbable screw in BPTB group and endobutton in HT group. Tibial fixation was achieved with bioabsorbable interference screw in both groups. Femoral and tibial tunnel widths of groups were compared on digital radiographs. RESULTS: When we compared the baseline values with the second-year results, the mean of femoral tunnel widths were significantly lower on radiographs at the second-year evaluation in both groups (p<0.001 for all). However, the means of tibial tunnel widths were significantly lower only in the BPTB group (p<0.001 for BPTB group and p=0.616 for HT group). Change levels of anteroposterior and lateral widths were more prominent in BPTB group than HT group (p<0.001 for all). CONCLUSION: Changes in tunnel widths show us superior ossification in BPTB grafting. This can be explained by superior bone-to-bone healing. As a result of radiological evaluation, we think that BPTB grafting can be more strong and durable.

Radiological and functional comparison of single-bundle anterior cruciate ligament reconstruction: transtibial versus anteromedial technique

Background/aim: This study aimed to compare radiological and functional outcomes of patients who had single-bundle anterior cruciate ligament (ACL) reconstruction with autologous hamstring tendon grafts using transtibial (TT) versus anteromedial (AM) femoral tunnel drilling techniques. Materials and methods: Sixty patients who had been operated on between 2010 and 2013 were enrolled in this study. Tunnel positions and widenings in the femur and tibia were evaluated with radiographs, arthrometric measurements with a Rolimeter arthrometer (Aircast, Summit, NJ, USA), stability assessment with Lachman and reverse pivot shift tests, and functional assessment with the International Knee Documentation Committee and Tegner and Lysholm scoring systems. Results: Tunnel enlargement in the sagittal and coronal planes of the femur was higher with the TT technique (P < 0.0001) and that of the coronal planes of the tibia was also higher with the TT technique (P = 0.01). During the assessment with the Rolimeter, the difference between sides was significant with the TT technique (P = 0.013). Positive results of the Lachman and reverse pivot shift tests were more frequent with the TT technique (P < 0.05), and the Lysholm scores were higher with the AM technique (P = 0.001). Conclusion: ACL reconstruction with hamstring autografts by either TT or AM technique demonstrated similar and excellent results in terms of functional outcomes at the end of the first postoperative year. The TT group had increased tunnel enlargement, which may have uncertain long-term outcomes, compared with the AM group.

Total patellectomy for patellar aneurysmal bone cyst.

Herein we report a case of patellar aneurysmal bone cyst of a 32-year-old female patient who was admitted to our outpatient clinic due to the swelling on her left knee. She was describing no trauma history but increasing pain and that the mass was expanding gradually by the time. Although it occurs rarely in patella, evaluation by radiographic and magnetic resonance images revealed that the mass was due to the patellar aneurysmal bone cyst, which also destructed the surface of the joint. Although there was no impairment in the range of motion of the patient's left knee in the preoperative evaluation, because of the destruction, we performed total patellectomy and extensor mechanism reconstruction by Zaricznyj technique instead of curettage and grafting. The patient was satisfied with the procedure performed after the surgery and there was no complication in the follow-up.

Achilles Tendon Open Repair Augmented With Distal Turndown Tendon Flap and Posterior Crural Fasciotomy.

The aim of the present study was to investigate the outcomes after open repair of Achilles tendon rupture augmented with a distal turndown gastrocnemius flap and deep posterior crural fasciotomy based on the modified Lindholm technique. Twenty-three patients with acute Achilles tendon injury underwent open end-to-end tendon repair augmented with a distal turndown gastrocnemius flap and deep posterior compartment fasciotomy. The concentric and eccentric muscle strength was measured using a functional squat system, and dynamic balance was assessed using the Y-balance test with anterior, posteromedial, and posterolateral reach distances. Jump performance was assessed using the vertical jump and 1-leg hop tests. All patients returned to their preinjury activity level, and their mean American Orthopaedic Foot and Ankle Society hindfoot scale score was 98.2 ± 2.3 after surgery. No significant difference was found between the involved and uninvolved extremities in terms of concentric and eccentric muscle strength (p = .82 and p = .53, respectively). In addition, no significant differences were seen between legs in the vertical jump (p = .16), one-leg hop (p = .15), and balance (p > .05) tests. Open end-to-end repair of the Achilles tendon rupture with augmentation and fasciotomy of the deep posterior compartment healed without any major complications. Functional performance of the involved leg after recovery was similar to that of the uninvolved leg. The modified Lindholm surgical technique described in our report appears to be a useful intervention for acute Achilles tendon rupture.

A comparison of ultrasonography and radiography in the management of infants with suspected developmental dysplasia of the hip.

The aim of this study was to determine the sensitivity and specificity of plain radiography in the detection of developmental dysplasia of the hip, using hip ultrasonography as a reference standard. A retrospective review was made in 44 infants ranging in age from 4 weeks to 50 weeks (mean age: 21.7 weeks). Both radiographic and ultrasonographic images were obtained for 86 hips. Radiography and ultrasonography were found to be significantly correlated in terms of classification of developmental dysplasia of the hip presence or absence (p < 0.0001, Fisher's exact test). With ultrasonography accepted as the standard for the diagnosis of developmental dysplasia of the hip, radiography had a sensitivity of 61% and a specificity of 87%. The results of this study suggest that the two imaging methods give similar overall results, but that low grade dysplasia detected on ultrasonography may go undetected on radiography.

[Effect of glucosamine chondroitine sulphate on repaired tenotomized rat Achilles tendons]. / Glukozamin kondroitin sülfatin onarilmis tenotomize siçan Asil tendonlari üzerine etkisi.

OBJECTIVES: We evaluated the effects of glucosamine chondroitine sulphate (glcN-CS) on rat Achilles tendons in this experimental animal study. MATERIALS AND METHODS: Thirty Wistar albino type rats weighing 300-350 g were randomly grouped into two. Group A: Achilles tendons were tenotomized, repaired and, glcN-CS given orally. Group B: Achilles tendons were tenotomized and repaired. All the rats were fed with pellet chow. Five rats in each group were sacrificed at 4, 8, and 12 weeks interval. Tensile strength of three tendon specimen from each group were tested biomechanically and two specimen were analysed histopathologically via immunohistochemical staining and hematoxylin and eosin staining. Contralateral side Achilles tendons were also grouped and analyzed as controls (group C and D). RESULTS: Histological results showed well organized collagen formation and less inflammation in group A. Biomechanical testing showed higher tendon strength in group A at eight weeks which is not statisticaly significant (55.3±4.84N, p=0.078). Rats which were were given glcN-CS had greater tendon strength which is statisticaly significant (50.01±5.62, p=0.014). CONCLUSION: Glucoseamine chondroitine sulphate improved results of Achilles tendon healing in rats. This result might be due to decreased inflammation and stimulation of collagen synthesis. Although glcN-CS is recommended only in osteoarthritic patients to relieve symptoms and signs it can also be prefered in treatment of soft tissue injuries formed during sports activities.

Idiopathic hypoparathyroidism mimicking diffuse idiopathic skeletal hyperostosis.

Idiopathic hypoparathyroidism is an uncommon disease caused by insufficient secretion of parathyroid hormone. Idiopathic hypoparathyroidism may cause various musculoskeletal findings, including diffuse ligamentous and entheseal ossifications. Diffuse idiopathic skeletal hyperostosis is a disorder of the elderly characterized by ossification of the anterior longitudinal ligament of the spine and various extraspinal ligaments. We present a 50-year-old man with idiopathic hypoparathyroidism who had been diagnosed as having DISH at 40 years of age. Resistant neck, left shoulder, and left hip pain did not improve with calcium and calcitriol treatment after diagnosis of idiopathic hypoparathyroidism.

Restricted scapular mobility during arm abduction: implications for impingement syndrome.

Scapular mobility plays a central role in normal shoulder function, and alterations in scapular mobility have been suggested as a factor in impingement syndrome. We therefore measured the effect of restricted scapular mobility during arm abduction on acromiohumeral and coracohumeral distances. For the control measurements, healthy volunteers (n = 10, all male, age range 25-35 years) underwent multislice computed tomography in a supine position, with the humerus actively maintained in the scapular plane at 45 degrees internal rotation and 60, 90 or 120 degrees abduction. To restrict scapular mobility a custom-made brace was then placed on each volunteer and fastened firmly with bandages, and the measurements were repeated. From the three-dimensional images the acromiohumeral and coracohumeral distances were measured. With the humerus in 90 degrees abduction, the acromiohumeral distance was significantly reduced (Student's t test). This result suggests that impingement syndrome may have a functional component.

Cemented endoprosthetic replacement for metastatic bone disease in the proximal femur.

In long bones, the most common site for metastases is the proximal femur. For lesions involving this region, osteosynthetic devices frequently fail, and for this reason, endoprosthetic reconstruction may be the optimal choice for treatment. Here, we present a series of 44 patients in whom 45 endoprosthetic reconstructions were performed for metastatic disease. In 28 patients (63.63%), endoprosthetic reconstruction was performed for pathologic fractures, and in 16 patients (36.37%), it was performed for impending fractures indicated by complaints of pain and problems with walking. Full weight bearing was achieved in the early postoperative period in 72.09% of our patients, and sufficient pain control was obtained in all patients. Four patients did not survive past the first 72 hours after surgery, and 11 more patients died within 2 months after surgery. A total of 29 patients (65.9%) survived to the 2-month follow-up visit, and of these, only 12 patients (27.2%) survived past the first postoperative year. We believe that in patients with metastatic disease in the proximal femur, endoprosthetic reconstruction can provide early and stable fixation with pain reduction and good functional results.

Avulsion fracture of the anterior inferior iliac spine.

A 14-year-old was admitted with right groin pain which has started after kicking ball in a football game one week before. He had limited active and passive hip extension. A plain AP radiograph of the pelvis revealed a bone fragment displaced inferiorly about 1 cm from the right anterior inferior iliac spine. The patient was treated conservatively with analgesics and limited weight bearing. Four weeks later, range of motion was normal without pain and at eighth week the hip flexors regained full strength.

Giant cell tumor of the talar neck.

We describe a patient with a giant cell tumor in the talar head and neck of the left foot who was diagnosed as having osteochondritis dissecans and treated with arthroscopic drilling in this same location 3 years earlier. Giant cell tumors can be confused with several conditions, including giant cell reparative granulomas, brown tumors, and aneurysmal bone cysts. Giant cell tumors of bone typically occur in the epiphysis of long bones, including the distal femur and proximal tibia. They are uncommonly found in the small bones of the foot or ankle, and talar involvement is rare. Despite this rarity, the radiographic appearance and clinical signs of talar lesions should be considered in the differential diagnosis of nontraumatic conditions in the foot.

Compartment syndrome in the hand due to extravasation of contrast material.

Extravasation of contrast material is a well-recognized complication of contrast-enhanced imaging studies. Most extravasations result only in minimal swelling or erythema; however, severe skin necrosis, ulceration and compartment syndrome may occur with extravasation of large volumes. This article presents a patient in whom extravasation developed after computed tomography (CT) contrast material was injected intravenously in the dorsum of the hand. Compartment syndrome was diagnosed, and the patient underwent fasciotomy. In follow-up, the patient regained full use of the hand. Although the use of contrast material has significantly improved the diagnostic accuracy of CT, anaphylaxis and contrast material extravasation are important complications. Selection of non-ionic contrast material, careful evaluation of the intravenous administration site and close monitoring of the patient during contrast material injection may help minimize or prevent extravasation injuries.

The management of complicated sternal dehiscence following open heart surgery.

BACKGROUND: Wound infection after median sternotomy for cardiac or thoracic surgery is a serious complication, and there is a lack of agreement regarding the best treatment method. We present our results in patients with mediastinitis treated with longitudinally affixed titanium plates on sternal halves. METHODS: The technique was composite closure using titanium fixation plates to buttress the sternum in combination with circumferential stainless steel wires. The series included 21 patients who developed sternal non-union resulting from mediastinitis. Mobilization of muscular flaps was performed in 8 cases. This technique also consists of sternal and soft tissue debridement and wound closure over mediastinal tubes with continuous irrigation and drainage. Antibiotherapy based on culture and sensitivity data continued for 4 to 7 weeks. RESULTS: Twenty patients achieved complete wound healing without further operative intervention or major complication. Nineteen patients treated with this technique survived. One patient died from sepsis after developing residual focus of chondritis and undergoing wide resection of cartilage, and 1 patient died from complications of severe stroke. CONCLUSION: We had good success using aggressive early debridement, closure of the sternal halves with titanium plates, mobilization of muscular flaps, high-volume mediastinal irrigation, and intravenous antibiotics. This approach was a successful salvage technique for revision cases in achieving sternal stability and union when standard methods of closure failed or were unlikely to succeed.