Evaluating axial alignment and knee phenotypes in a young Indian population, using X-rays converted to three-dimensional bone models, and their relevance in total knee arthroplasty.

PURPOSE: The standard principle of total knee arthroplasty (TKA) targeted by most orthopaedicians is the alignment of the lower limb in a neutral mechanical axis. However, for several patients the neutral mechanical alignment is not normal. Aligning these patients to a neutral mechanical axis may not result in desirable outcomes as it may feel unnatural. This study aimed to discover what percentage of the young healthy Indian population have a neutral hip-knee-ankle angle (HKA = 180°) and what percentage of this population have a deviation from the neutral HKA. We also studied the distribution of knee phenotypes in this non-arthritic population. SUBJECTS AND METHODS: A total of 196 lower limbs were evaluated from 100 subjects, between the ages of 20 and 35 years, without any history of lower limb pathology, of which 50 were males and 50 were females. All volunteers were subjected to full-leg standing anteroposterior and lateral digital radiographs on which various alignment parameters were analysed. Three-dimensional bone models were generated using a validated software. RESULTS: 125 limbs (63.7%) from the total population lay in the range of 180 ± 3°; 7.14% (14/196) of the total limbs had an HKA angle of 180°; 29.5% (58/196) of the total population had a varus alignment, i.e., HKA angle of ≤176° and 6.6% (13/196) had knees in valgus alignment, i.e., HKA angle of ≥184°. Thirty-four percent (33/96) of limbs in men and 25% (25/100) of limbs in women had constitutional varus knees with an alignment of ≤176°; 5.2% (5) of limbs in men and 8% (8) of limbs in women had constitutional valgus knees with an alignment of ≥184°; 67/96 knees in males and 58 knees in females were in the range of 180 ± 3°. CONCLUSIONS: A significant portion of the normal population had limbs that deviated from the neutral HKA. If these subjects were to need TKA in the future, it would not be desirable to restore their alignment to its neutral.

Femur Shaft Fracture in a Polio Patient.

Introduction: Although poliomyelitis is on the verge of eradication, the survivors of this disease are still living with its complications. Polio survivors with its musculoskeletal complications will continue to be a part of our population for many more decades'. Although poliomyelitis in itself is not common today, fractures in polio affected patients' limbs are a common entity and are difficult to manage with common fracture management protocols. Case Presentation: This study presenting a case of 58-year-old male with alleged history of twisting of the right lower limb while walking. X-rays suggested fracture right shaft femur. Patient had a history of poliomyelitis with the right lower limb affection and had a fixed flexion deformity of 15° at the right knee joint. The patient had to undergo two surgeries. In the first procedure, distal femur plating was done through lateral approach. Due to radiological signs of non-union, in the next procedure, additional medial plate was added and bone grafting was done to ensure stable fixation and union. Conclusion: Treating a fracture in a polio affected limb is a challenging task taking into consideration the previous bony deformity as well as the myopathy. Knowledge of treating these fractures as well as pre-operative planning is important to a trauma surgeon as such scenarios are not very rare.

A Study of Surgical Accuracy with X-Ray-Based Patient-Specific Instrument (X3DPSI®) vs Conventional Instrument in Total Knee Arthroplasty Surgeries.

Introduction: Patient-specific instruments (PSI) have been shown to be a good solution in getting accurate bone cuts in total knee arthroplasty (TKA) in many studies. However, the need for an extra CT/MRI makes the existing PSI method costly and unsafe. X-ray-based PSI can solve these problems, if proven to be accurate. The purpose of this study was to introduce a novel method to measure the performance of X-ray to 3D-based PSI (X3DPSI ® ) in achieving planned bone cuts by comparing with conventional instruments (CI). Materials and Methods: This was a prospective study of a total of ten patients undergoing TKA surgery. Preoperative full length lower limb scanogram was done with specialized calibration strap-on marker to develop X3DPSI ® which was used intraoperatively for the placement of guiding pins for the cutting jig. Similarly, intraoperative guide pins were placed using CI also. Calibrated intraoperative X-ray images, in AP and LAT view, were taken while the cutting-block guiding pins were placed on the distal femur and proximal tibia. These X-ray images were used to calculate the cutting plane alignments for femur and tibia and to simulate the postoperative hip-knee-ankle (HKA) angle and MAD (mechanical axis deviation), in a virtual Tabplan3D environment for both the methods. Results: The results showed that there was a significant difference between the two methods in terms of femoral cutting plane angles and in terms of the HKA angles and MAD. There was no significant difference in the tibial cutting plane angles in the coronal plane. Conclusion: The mechanical axis alignment achieved based on the virtual cuts made using the X3DPSI ® was significantly better than the alignment achieved based on the cuts made using the CI, in terms of both HKA and MAD. This novel method of X-ray-based PSI is a low-cost alternative to CT/MRI-based PSI if found to be accurate in future planned studies.

CT-Based 3D Reconstruction of Lower Limb Versus X-Ray-Based 3D Reconstruction: A Comparative Analysis and Application for a Safe and Cost-Effective Modality in TKA.

AIM: Patient Specific Instrumentation (PSI) with 3D bone models have been used to improve the outcomes of Total Knee Arthroplasty (TKA). The PSI, however, needs a CT (Computed tomography)/MRI scan to reproduce a bone-based model. However, CT is not a routine imaging method in the TKA and has challenges such as high radiation exposure and increased investigation cost. Any technology or software which could accurately recreate 3D bone models using X-ray would be a cheaper and safer tool. This study is based on one such technology (XrayTo3D®) using X-ray to 3D as an alternative to other image-based 3D bone models and PSI available in the market. This study compares the accuracy of XrayTo3D® versus a Conventional CT to 3D, in the reconstruction of lower limb bones (femur and tibia). METHOD: In an analysis of 45 lower limbs, 11 anatomical parameters were measured [Medial Proximal Tibial Angle-MPTA, Tibial(T)-torsion, T-slope, T-length, Mechanical Lateral Distal Femoral Angle (mLDFA), F-version, F-length, Distal femoral Medio lateral width (F-ML), Distal Femoral Antero Posterior (F-AP), Proximal Tibia Antero Posterior (T-AP), Proximal Tibia Medio Lateral (T-ML) based on landmarks selected by three orthopaedic surgeons(numbers of the authors superscript), on two groups of 3D models, one reconstructed using XrayTo3D® and the other using CT. Mean and standard-deviation values were measured for all the parameters in both the groups. Statistical association between both the groups was measured by Pearson's correlation coefficient. Two-sided t tests of the mean values were calculated to compare the two measurement methods. The interobserver reproducibility within each group was measured by the intraclass correlation coefficient (ICC). Point-to-surface (P2S) error, in the distal femur and proximal tibia regions of the models reconstructed using XrayTo3D®, were also measured. RESULTS: For all the 11 parameters, no statistically significant difference was found between the 2 groups (p > 0.05). Pearson's correlation coefficients for all the parameters were not significant. The interobserver reproducibility was ranging from 0.90 to 1.00 and 0.90 to 1.00 for the XrayTo3D® and CT groups, respectively. The mean P2S distance was 1.0 mm in distal femur and 1.1 mm in proximal tibia which was within the acceptable limits. CONCLUSION: The reconstruction accuracy of the XrayTo3D® is an accurate, safe and cost effective as compared to a CT-based method.

Is obesity a contraindication for simultaneous bilateral total knee arthroplasty? A prospective case-control study.

AIM: Total Knee Arthroplasty (TKA) for decades has been an effective treatment modality for chronic arthritis of the knee. However, there is scarcity of literature comparing the functional outcomes of simultaneous bilateral TKA in obese patients with non-obese Indian population. We conducted this study to evaluate the functional outcomes and complication rates of simultaneous bilateral TKA in obese patients matched control with non-obese patients. MATERIALS AND METHODS: We divided the patients into two study groups based on their body mass index (BMI). Patients with a BMI of less than 30 were classified as non-obese and those with a BMI of more than 30 were classified as obese. All the patients underwent simultaneous bilateral TKA by a single surgeon using the same implant and technique. Patients were followed up regularly and functional outcomes in terms of Oxford knee score were noted at 6 weeks, 3 months, and 1 year. Post-operative complications and time to recovery was also compared. RESULTS: Mean follow-up in obese group was 18 months (12-25 months) and in non-obese group was 17 months (12-24 months). Both the groups were matched with control in terms of pre-operative parameters. Post-operative hemoglobin drop, ICU requirement, length of hospital stay, mean walking time, and mean time to climbing stairs were similar in both the groups. Oxford knee score was significantly better in non-obese group at 6 weeks, but was similar in both the groups at 3 months, 6 months, 1 year, and last follow-up. There was no statistically significant difference seen in the complication rate in both the groups. There was no implant loosening or radiolucency seen. CONCLUSION: We conclude in our study that simultaneous bilateral TKA gives comparable mid-term results in obese patients in comparison to the non-obese patients.

Tuberculosis (T.B.) masquerading as tumor. An 8-year study on 25 cases of long bone tuberculosis presenting as tumors.

AIM: To highlight radiological features and emphasize the need for tissue diagnoses to confirm bone pathology. Tuberculosis is known to present without constitutional symptoms and with unconventional imaging features mimicking sarcomas as shown in our series of 25 patients; where the imaging and biopsy protocols at our institute helped to solve these diagnostic dilemmas. MATERIAL AND METHODS: We retrospectively analyzed clinical and radiological features and tissue diagnoses in 25 patients referred to the department of orthopedic oncology with radiological suspicion of tumor. RESULTS: Only 7 patients had cultures positive for Mycobacterium Tuberculosis T.B. Radiological features suggestive of infection were Metaphyseal and joint involvement, permeative lesions, absence of Codman's triangle, and soft tissue mass suggestive of a cold abscess. The predictive accuracy of the orthopedic oncologist was 60% and musculoskeletal radiologist was 72% (based on radiology). Final diagnosis is 100% confirmed on histopathology. CONCLUSION: Diagnosis based primarily upon imaging is a wrong approach. A multimodal approach to differentiating tuberculous bone infections from sarcomas is essential.

Is vitamin D deficiency behind the scenes for high incidence of Giant cell tumor amongst the Indian population? Unraveling the vitamin D - RANKL association.

INTRODUCTION: The major neoplastic and proliferative component of GCTB is the stromal tumor cells; that they have shown no evidence of bone destruction, instead the massive tissue destruction appears to be a result of tumor induced osteoclastogenesis. The discovery of receptor activator of nuclear factor kB (RANK) and RANK binding ligand (RANKL) uncovered the bone homeostasis and molecular mechanism by which multiple compounds (including vitamin D) regulated osteoclast differentiation; a function mediated by osteoblastic cells and osteoclast-precursor cells. HYPOTHESIS: In a country burdened by vitamin D deficiency, causal relation between hypovitaminosis D and GCTB was hypothesized based on the vitamin D mediated RANKL expression and osteoclastogenesis, as India is also a population with higher incidence of GCTB as compared to Western populations described in the literature. The possibility of vitamin D regulated osteoclastogenesis in GCTB is postulated on the evidence from molecular research linking it to the RANK/RANKL/OPG pathway. The aim of this study was to analyse the prevalence of Vitamin D deficiency in patients with primary GCTB and to elucidate any difference in serum Vitamin 25(OD)D3 levels amongst the matched control population data. MATERIALS AND RESULTS: 130 patients of primary GCTBs were matched to 310 controls from the general health check population and serum levels of 25(OH)D3 were analyzed. Statistical analysis performed on the non-parametric data and Mann Whitney U Test used to derive inference with significance set at p < 0.05. 56 females and 76 males with median Vitamin D level in the GCTB group was 15.9 ng/ml (Mean 19.41; Range 1.03 to 92) as compared to the control population with median level of 22.2 ng/ml (Mean 25.1; Range 2.6 to 87.9). The results were significant (p value < 0.05) as compared to the control population in all decades except the third decade (p value 0.0548). DISCUSSION: The differential expression of RANKL and OPG in response to levels of vitamin D has been established. The stromal cells of osteolytic GCTB express high levels of RANKL, which is a key signal regulator in development of this disease and bone destruction typical of GCTBs. This has resulted in research targeting this pathway for therapeutic approach in GCTBs. As vitamin D supplementation is simple and safe, increased awareness to assess and if necessary correct vitamin D status of patients is warranted, however the question as to whether patients with low vitamin D levels are more prone to develop GCTB and thus would profit from vitamin D supplementation remains unanswered. To conclude, it is essential to assess vitamin D levels in patients with GCTB as deficiency is pronounced. Future research on this hypothesis might lead to an association between Vitamin D deficiency and the onset/natural history of GCTB that may in the future help us cure or prevent GCTBs.

Radiation-Induced Wound Infections in Operated Soft Tissue Sarcomas: An Unbelievable Challenge in a Series of Five Cases.

INTRODUCTION: The standard modality for the treatment of soft tissue sarcomas is a wide excision followed by radiation therapy either in the form of external beam radiation or brachytherapy. Radiation therapy thus is an integral part of management and limb salvage in these cases. This, however, subjects the irradiated tissue to a greater risk for necrosis and local infection. This study suggests a protocol to manage these infections. A multimodal approach to these problems is important. Studies have shown that the use of negative pressure wound therapy (NPWT) in non-healing wounds significantly reduces edema by removing excessive fluid from the wound bed as well as facilitating removal of the infective pathogen after an aggressive wound debridement. The author has judiciously used NPWT in each of these patients with encouraging results. With no well-defined guidelines to manage radiation-induced wound infections, this retrospective study gives an overview and protocol for a systematic approach. CASE REPORT: This is a retrospective series of five cases managed between January 2014 and December 2016. All were men with a mean age of 30.6 years with a mean follow-up of 27 months. We analyzed their demographic, clinical data, history, wound locations, primary diagnosis on histopathology, organisms isolated on culture, surgical details, antibiotics administered, and special interventions such as skin flaps or grafting and clinical outcome.Of the five, three patients received exclusive external beam radiation therapy (EBRT) and two were given intralesional brachytherapy and EBRT. Three received additional chemotherapy. 7/9 isolated organisms were multidrug-resistant mean 5.4 cycles of NPWT after aggressive debridement was needed to achieve healthy granulation tissue bed. Wounds were closed at median 31.5 days (three split-thickness split skin grafting, one local rotation flap, and one healing with secondary intention). We had two mortalities secondary to metastasis. CONCLUSION: We recommend aggressive debridement, prolonged use of NPWT in infected irradiated wounds, and appropriate antibiotics with soft tissue cover by a multidisciplinary team to achieve good results.

Bizarre Parosteal Osteochondromatous Proliferation- A Case Series of Typical and Atypical Presentations.

INTRODUCTION: Bizarre parosteal osteochondromatous proliferationis a distinct entity which requires proper radiological and pathological distinction for correct surgical management. CASE REPORT: We present a series of four cases which were misdiagnosed by the treating surgeons, reporting radiologists and pathologists due to clinical and investigatory consistencies with other benign or malignant orthopedic tumors. Due to common diagnostic errors of these uncommon tumors, the patients had recurrence and required multiple invasive procedures which could have been avoided with high index of suspicion. CONCLUSION: Dueto high local recurrence rates and a lack of adjuvant therapy options, this lesion will continue to pose a challenge for orthopedic surgeons and more awareness ofthis lesion will help identify and understand that a wide excision, with no compromise related to the margins, is required for this benign-appearing lesion.