Functional Outcome of Bilateral Total Knee Replacement in Advanced Osteoarthritis in Simultaneous Versus Staged Procedure.

Osteoarthritis (OA) is a chronic, progressive disease involving the degeneration of cartilage and joint tissue, resulting in pain and disability. Bilateral total knee arthroplasty (TKA) is is an effective intervention that improves quality of life, reduces pain and increases functional capability. This study was performed to compare the functional outcomes between staged and simultaneous total knee arthroplasty. This prospective interventional study was carried out in Arthroscopic and Arthroplasty unit of BSMMU, Dhaka from January 2017 to December 2018. A total of 60 OA patients underwent TKA were included in this study. Thirty patients underwent simultaneous TKA procedure and 30 patients underwent staged TKA procedures performed with 1-6 months between stages were included. Pre-operative and post operative data were collected. Data were analyzed using SPSS 12.0. Numerical data were analyzed using unpaired t test and categorical data were analyzed using Chi-Square test. A value of p<0.05 was considered statistically significant. Mean age of the study subjects was 60.47±10.13 years in staged group and 59.30±9.90 years in simultaneous group. Male to female ratio was 1:1.5 in staged group and 1:2 in simultaneous group. Mean BMI of the study subjects was 30.70±4.91kg/m² in staged group and 30.06±4.79kg/m² in simultaneous group (p>0.05). In both groups, maximum study subjects were housewife (33.3% vs. 33.3%). In staged group 13.3% and 16.7% in simultaneous group were heavy worker; 20.0% in staged group and 16.7% in simultaneous group were medium worker (p>0.05). Pain, motion, stability and function were significantly changed after surgery comparing before surgery.Infection was observed in 10.0% cases in both groups. Stiffness was observed in 10.0% cases in staged group but in 6.7% cases in simultaneous group. Even final outcome showed better in simultaneous procedure, there was no significant difference between two procedures. The outcome of both simultaneous andstaged procedure of bilateral total knee replacement in Advanced Osteoarthritis is similar.

Terahertz photonic integrated circuit for frequency tuning and power modulation.

The quantum cascade laser is a powerful solid-state source of terahertz-frequency radiation. However, integrating multiple photonic functions into a monolithic platform in this frequency range is non-trivial due to the scaling of photonic structures for the long terahertz wavelengths and the low frequency tuning coefficients of the quantum cascade lasers. Here, we have designed a simple terahertz-frequency photonic integrated circuit by coupling a racetrack resonator with a ridge laser in the longitudinal direction to design a notch filter. The transmission properties of this filter structure are dependent on the phase matching and losses in the coupled racetrack and results in a comb of stopband frequencies. We have optimized the comb separation by carefully selecting the cavity dimensions of the racetrack resonator to suppress longitudinal modes in the ridge laser enabling single-mode emission. The emission frequencies and output power from laser are controlled through appropriate control of drive currents to the ridge and the racetrack resonator. The emission frequency is electrically tuned over ∼81 GHz exploiting Stark shift of the gain as a function of drive current at the ridge laser, coinciding with an output power variation of ∼27% of the peak power (at a heat sink temperature of 50 K). The output power from the ridge also varied by ∼30% and the frequency was tuned by a further 10 GHz when the driving conditions at the ridge laser are invariant and the current at the racetrack resonator was varied. To our best knowledge, this is the first report of a frequency engineering, tuning and power modulation of terahertz-frequency quantum cascade lasers using a photonic integrated circuit.

Early Functional Outcome of Wide Resection and Endoprosthesis Replacement for Recurrent Giant Cell Tumour of the Distal Femur.

Giant cell tumors (GCT) are usually benign bone tumors with aggressive characteristics. Giant cell tumors have a benign indolent course in most patients, but tumors may recur locally in as many as 50% of cases depending on the type of treatment and initial presentation of the tumor. The aim in the management of long bone GCT is to eradicate the tumor and prevent local recurrences. In this study, we retrospectively assessed the functional outcomes in 5 patients having recurrent GCTs of the distal femur treated with custom made modular endoprosthesis following wide resection of the tumor from January 2017 to December 2018 in Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh. Tumor Society functional score (MSTS) was used to assess the results of our patients. The mean follow-up period was 13.2 months. We achieved good to excellent results with our mean functional score of 80.66%. To the best of our knowledge, probably first started by us using customized modularendoprosthetic massive replacements for recurrent GCTs in our country. The use of custom made modular mega prosthesis is a simple and technically superior method of feeling the bone defects after wide resection in aggressive recurrent GCTs. In our opinion endoprosthesis replacement for recurrent GCTs had early good to excellent functional results 5.

Giant optical nonlinearity interferences in quantum structures.

Second-order optical nonlinearities can be greatly enhanced by orders of magnitude in resonantly excited nanostructures. These resonant nonlinearities continually attract attention, particularly in newly discovered materials. However, they are frequently not as heightened as currently predicted, limiting their exploitation in nanostructured nonlinear optics. Here, we present a clear-cut theoretical and experimental demonstration that the second-order nonlinear susceptibility can vary by orders of magnitude as a result of giant destructive, as well as constructive, interference effects in complex systems. Using terahertz quantum cascade lasers as a model source to investigate interband and intersubband nonlinearities, we show that these giant interferences are a result of an unexpected interplay of the second-order nonlinear contributions of multiple light and heavy hole states. As well as of importance to understand and engineer the resonant optical properties of nanostructures, this advanced framework can be used as a novel, sensitive tool to elucidate the band structure properties of complex materials.

Detection sensitivity of laser feedback interferometry using a terahertz quantum cascade laser.

We report on the high detection sensitivity of a laser feedback interferometry scheme based on a terahertz frequency quantum cascade laser (QCL). We show that variations on the laser voltage induced by optical feedback to the laser can be resolved with the reinjection of powers as low as ∼-125 dB of the emitted power. Our measurements demonstrate a noise equivalent power of ∼1.4 pW/√Hz, although, after accounting for the reinjection losses, we estimate that this corresponds to only ∼1 fW/√Hz being coupled to the QCL active region.

Anterior Cruciate Ligament Reconstruction Using Autologous Hamstring Double Bundle Graft Compared With Single Bundle Graft Procedures.

Anterior cruciate ligament injury is one of the commonest sports injuries, which often markedly reduces activity and the quality of life. The autologous hamstring double bundle graft and single bundle graft are commonly used for anterior cruciate ligament reconstruction. The choice of graft material for ACL reconstruction is believed to play a major role in the outcome but still there are controversies about the graft selection for primary ACL reconstruction. The aim of this study was to compare the clinical and functional outcome of autologous double bundle (DB) hamstring graft and single bundle (SB) hamstring graft reconstruction for the ACL injury. This prospective observational study was conducted in the Department of Orthopaedic Surgery, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from March 2015 to September 2017. Total 42 cases of ACL injury that required reconstruction surgery was selected as per inclusion criteria. Total patients were allocated into two groups. One group was treated by single bundle graft and other group was treated by double bundle graft for the ACL reconstruction. In this study, the mean age of double bundle and single bundle groups were 28±6.63 and 30.14±7.55 years respectively and majority of the subjects were male. The post-operative symptoms and signs were more improved in double bundle group than single bundle group during last follow-up period of 6th months. The Lachman test, Anterior drawer test and pivot sift test were more negative in double bundle group than that of single bundle groups. The Lysholm and Tegner activity were better in double bundle group than single bundle group. Again rotational and anterior stability of the knee was better in the double bundle group. However, the differences were not statistically significant and all patients in our study were able to return their activity. Double bundle group showed better rotational stability than the single bundle groups and all knees were improved by anterior cruciate ligament reconstruction compared with their pre-operative status.

Comparative Study of Patellar Tendon Graft versus Hamstrings Graft for Anterior Cruciate Ligament Reconstruction.

Graft selection for primary anterior cruciate ligament reconstruction is very important part of knee stability. The purpose of this Qasi experimental study was to compare the clinical outcomes after ACL reconstruction using either a BPTB graft or a four-strand hamstrings graft and conducted from January 2012 to December 2013. Patients presented with a symptomatic unilateral ACL rupture who were underwent ACL reconstruction by using either BPTB or Hamstrings graft, IPD of Department of Orthopedics at Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka as well as in a private hospital in Dhaka, Bangladesh were selected as study population. Patients were divided into Group A who were treated with the patellar tendon bone graft and Group B patients who were received hamstrings tendon graft. All surgery was performed by the same surgeon and the both procedures were arthroscopically assisted. Operation was performed at least three (03) weeks after initial trauma. All patients were assessed by independent examiner before surgery, at 6 months, 12 months and then annually by clinically. A total number of 70 patients were recruited for this study. The mean age with SD of Group A and Group B were 27.31±10.91 and 26.97±10.10 years respectively (p=0.892). Tegner scores were measured preoperatively and post-operatively. The score were 2.2±1.1 and 2.1±1.0 in preoperatively (p=0.817). In post-operatively the mean score were 6.0±1.7 and 5.8±1.5 in Group A and Group B respectively (p=0.508). Regarding outcome of the operation excellent was 18(51%) cases in both Group A and Group B, good was 15 (43%) and 16(46%) cases in Group A and Group B respectively (p=0.793). In conclusion there was no significant difference between the two groups of the ACL reconstructions cases.

Close Intramedullary Interlocking Nailing Versus Locking Compression Plating In the Treatment of Closed Fracture Shaft of the Tibia.

Fracture of tibial shaft is the commonest site of long bone fractures due to its superficial location involving young or middle-age people. Proper management is an important issue regarding the future effective movements. In this study patients were grouped in closed Intra medullary interlocking nailing and locking compression plating. Post-operative follow up at 2 weeks, 6 weeks, 12 weeks and 3 months thereafter up to 6 months were done. Each of the patients was evaluated clinically and radiologically by tucker criteria of Tuker et al. Patients were assessed for pain on full weight bearing and kneeling, shortening and range of motion of knee and ankle joints. Radiological assessment for union of fracture, alignment of fracture and angulations and position of nail and screws and infection were observed during follow up. A total number of 32 patients were selected but only 27 patients were available for follow up for a period of 6 months. They were grouped into Group A, consisting of 15 patients who took the treatment in the form of closed intramedullary interlocking nailing and Group B, consisting of 12 patients those underwent ORIF with locking compression plating. In both of the groups Motor Vehicle Accident was the main mechanism of trauma. Fracture involving the middle 3rd of the tibia is common in both the groups. During post-operative follow up, four patients in Group A complained anterior knee pain, one patient in Group B had superficial infection, most of the patients had no restriction of movement in the ankle and knee joints and a single patient in Group B showed 1.5cm shortening of the lower limb. Period of hospital stay and fracture union time were less in Group A, which was statistically significant. Both groups showed excellent result with minimum complications. So this study permits to conclude that close IM interlocking nailing and open reduction and internal fixation by locking compression plating is equally effective for the management of close fracture shaft of the tibia.

Correlation between Clinical and Arthroscopic Findings in Meniscal Tear of Knee.

The meniscus is the most commonly injured structure in the knee joint. Carefully performed clinical examination can give better diagnosis of meniscal tear. The aim of this study was to find out the correlation between clinical and arthroscopic findings in meniscal tear of knee. This cross sectional observational study was conducted in the Department of Orthopaedic Surgery, BSMMU, Dhaka from July 2012 to June 2014. Thirty patients of meniscal tear were selected as per inclusion and exclusion criteria. After proper evaluation and clinical examination of these patient arthroscopic examinations was done under spinal anesthesia. A total number of 30 patients were recruited in this study. Twenty seven (90%) patients were male and only 3(10%) were female. Mean±SD of age was 26.00±5.55 and range was 17-34 years. Out of 30 patients 19(63.3%) had right knee affected and the rest 11(36.7%) had left knee affected. It was found from clinical diagnosis that most of the patients had MM injury (73.4%) and LM injury was in 26.6% patients. From arthroscopic diagnosis we found most of the patients had multiple types of injury (40.0%) followed by 26.7% patents had isolated MM injury, 16.6% patients had isolated LM injury, 10.0% patients had other injuries like ACL, PCL or MCL and rest 6.7% patients had no injury at all. Sensitivity, specificity, PPV, NPV and accuracy of clinical diagnosis in diagnosis of MM injury were 94.4%, 58.3%, 77.3%, 87.5% and 80.0% respectively. Sensitivity, specificity, PPV, NPV and accuracy of clinical diagnosis in diagnosis of LM injury were 85.7%, 91.3%, 75.0%, 95.5% and 90.0% respectively. Clinical evaluation may diagnose meniscal tear accurately.

Engineered far-fields of metal-metal terahertz quantum cascade lasers with integrated planar horn structures.

The far-field emission profile of terahertz quantum cascade lasers (QCLs) in metal-metal waveguides is controlled in directionality and form through planar horn-type shape structures, whilst conserving a broad spectral response. The structures produce a gradual change in the high modal confinement of the waveguides and permit an improved far-field emission profile and resulting in a four-fold increase in the emitted output power. The two-dimensional far-field patterns are measured at 77 K and are agreement in with 3D modal simulations. The influence of parasitic high-order transverse modes is shown to be controlled by engineering the horn structure (ridge and horn widths), allowing only the fundamental mode to be coupled out.

The study of the ideal curvature of metallic tracheostomy tube in ca larynx.

Twenty patients in the age group of 45-55 years with carcinoma of larynx underwent tracheostomy for acute upper airway obstruction. Tracheostomy tubes (no. 36) commonly available in the market have varying angle of curvatures ranging from 120° to 130°. In respect of different curvatures of the tracheostomy tubes, the various complaints of the patients were noted. The mean ideal angle of curvature of the tracheostomy tube should be 112° that was calculated from CT scan of neck with tube in situ.

Malignant melanoma of nose.

Malignant melanoma (MM) is one of the uncommon malignancies of the nose. We present an unusually big proliferative like MM in the vestibule of the nose. Malignancy of nose constitutes less than 1% of all malignancies (3% of head & neck tumour). MM however contributes only 2% of all malignant neoplasms of the nose (Moore & Martin. 1955).

Neurofibrosarcoma in the nasal cavity.

A nine month old male child presented with a swelling protruding from the right nasal cavity for two months. Other symptoms were mild breathlessness during suckling and blood stained nasal discharge. CT Scan sshowed a mass arising from the lasteral wall of the right nasal cavity with mild erosion of the adjacent bones. The tumor was excised with wide margin through a lateral rhinotomy approach under general anaesthesia. In histopathological examination it was found to be a low grade neurofibrosarcoma. The child recovered well and is free from any recurrence till the time of reporting.

Paraganglioma of external auditory canal.

In the ear, paragangliomas are commonly found in the tympanic cavity or in juglar bulb. We, here, present a case of paraganglioma originating from the external auditory canal as it has not been reported in the world literature. The clinico-pathologic features of such a case has been described.

Prognoma of maxilla.

Prognoma is a rare dysembryogenic tumour of infancy Very few cases have been recorded in the world literature so far A case report of this tumour affecting a female child with involvement of the right maxilla is being presented Histopathologically prognoma is a melanotic neuroectodermal tumour An increased level of a-fetoprotem m the serum and vanillylmendilic acid (V M A ) in a 24 hours urine sample have been reported with prognoma.