Precise Calibration of Femoral Component Rotation Using the Posterior Condylar Axis as a Reference during Image-free Robot-assisted Total Knee Arthroplasty: A Technical Note.

Introduction: The use of image-free robotic systems for total knee arthroplasty (TKA) is gaining popularity. Although the surgical transepicondylar axis (sTEA) is considered the optimal femoral rotational reference during TKA, it is difficult to define intra-operatively. Conventional and image-free robot-assisted TKA (RA-TKA) therefore rely on the use of Whiteside's axis (WSA) or the posterior condylar axis (PCA) as surrogate references. The PCA is considered to be associated with less variability than the WSA. The authors present a simple technique to permit calibration of femoral component rotation (FCR) using the PCA as a reference for image-free robotic systems that do not permit this option. Technique: The image-free robotic systems used by the authors (Navio and CORI, Smith and Nephew, Memphis, TN, USA) permit calibration of FCR only when the perpendicular to WSA is used as a reference. When the PCA is selected as a reference, a fixed 3° of external rotation is set by the robot. The technique proposed by the authors involves the use of the former setting, followed by internal rotation of the perpendicular to the WSA to co-align it with the PCA. The planning menu subsequently permits virtual surgical planning using the PCA as the femoral rotational reference and permits adjustments in rotational positioning of the femoral component while displaying the effect of rotation on bony resection and vice versa in real time. In addition, coaligning the perpendicular to the anatomic trans-epicondylar axis (aTEA) displays the internal rotation of the PCA with respect to the aTEA. This information can be used for setting rotational boundaries with respect to the PCA while using various alternate alignment strategies, like functional alignment, since the relation between the aTEA and sTEA is less likely to be affected by dyplasia and wear when compared with the PCA or WSA. Conclusion: This simple technique permits optimally calibrated rotational positioning of the femoral component during image-free RA-TKA, using the PCA as a reference. It can be applied for optimizing surgery in knees with altered or outlier anatomy, as well as routinely, especially when alternate alignment strategies are used.

Thrombosed Persistent Median Artery with Coexisting Bifid Median Nerve in a Robotic Arthroplasty Surgeon: A Case Report.

CASE: A 47-year-old orthopaedic surgeon presented with acute volar left wrist pain. He performed over 250 robot-assisted knee arthroplasties each year. Color Doppler evaluation revealed bilateral persistent median arteries and bifid median nerves, with focal occlusive thrombosis of the left median artery. He was advised rest and oral aspirin. He could return to his professional activities after 1 month. He had no recurrence of symptoms at 1 year of follow-up. CONCLUSION: Orthopaedic surgeons use vibrating hand tools on a daily basis. The possibility of hand-arm vibration syndrome must be considered in the differential diagnosis of wrist pain among orthopaedic surgeons.

Predictability of implant sizes during cruciate-retaining total knee arthroplasty using an image-free hand-held robotic system.

The use of appropriately sized implants is critical for achieving optimal gap balance following total knee arthroplasty (TKA). Inappropriately sized implants could result in several complications. Robot-assisted TKA (RA-TKA) using CT-based pre-operative planning predicts implant sizes with high accuracy. There is scant literature describing the accuracy of image-free RA-TKA in predicting implant sizes. The purpose of this study was to assess the accuracy of an image-free robotic system in predicting implant sizes during RA-TKA. Patients who underwent cruciate-retaining RA-TKA for primary osteoarthritis, using an image-free hand-held robotic system were studied. The predicted and implanted sizes of the femoral component, tibial component and polyethylene insert, for 165 patients, were recorded. Agreement between robot-predicted and implanted component sizes was assessed in percentages, while reliability was assessed using Cohen's weighted kappa coefficient. The accuracy of the robotic system was 63% (weighted-kappa = 0.623, P < 0.001), 94% (weighted-kappa = 0.911, P < 0.001) and 99.4% (weighted-kappa = 0.995, P < 0.001), in predicting exact, ± 1 and ± 2 sizes of the femoral component, respectively. For the tibial component, an accuracy of 15.8% (weighted-kappa = 0.207, P < 0.001), 55.8% (weighted-kappa = 0.378, P < 0.001) and 76.4% (weighted-kappa = 0.568, P < 0.001) was noted, for predicting exact, ± 1 and ± 2 sizes respectively. An accuracy of 88.5%, 98.2% and 100%, was noted for predicting exact, ± 1 and ± 2 sizes of the polyethylene insert respectively. Errors in predicting accurate implant sizes could be multi-factorial. Though the accuracy of image-free RA-TKA with respect to alignment and component positioning is established, the surgeon's expertise should be relied upon while deciding appropriate implant sizes.

Incidence and severity of COVID-19 infection post-vaccination: a survey among Indian doctors.

PURPOSE: The rollout of COVID-19 vaccines began in India in January 2021, with healthcare professionals being the first to receive vaccination. The purpose of this research was to study the incidence and severity of COVID-19 infections among Indian doctors, following vaccination with ChAdOx1 nCoV-19 or BBV152. METHODS: We conducted an online voluntary survey among Indian doctors who received one or two doses of ChAdOx1 nCoV-19 or BBV152. Questions pertaining to the incidence and severity of COVID-19 infection following vaccination were asked. Data thus obtained were analysed. RESULTS: 9146 doctors were included in this study. 8301 of these received ChAdOx1 nCoV-19, while 845 received BBV152. 2842 (31.07%) respondents reported having a COVID-19 infection following vaccination. Presence of pre-existing medical comorbidities was associated with a higher incidence, while prior COVID-19 infection and two doses of either vaccine were associated with a lower incidence of COVID-19 infection post-vaccination. Exposure to COVID-19 patients on a daily basis did not increase the incidence of COVID-19 infection among doctors who were vaccinated. Increasing age, male gender, presence of pre-existing medical comorbidities, and daily exposure to COVID-19 patients were associated with increased severity of COVID-19 infection after vaccination. Two doses of either vaccine resulted in less severity of disease compared to one dose. CONCLUSION: ChAdOx1 nCoV-19 and BBV152 confer immunity against severe forms of COVID-19 infections. COVID-19 infections prior to vaccination result in a lower incidence of breakthrough infection. Presence of pre-existing medical comorbidities is associated with increased incidence and severity of breakthrough infections.

Trunnion fracture of femoral prosthesis following a large metal-on-metal uncemented total hip arthroplasty: a case report.

BACKGROUND: Trunnion fracture of the femoral prosthesis is an extremely rare complication following Total Hip Arthroplasty (THA). There are very few reports in literature on trunnion fracture. All previously reported cases are of prostheses with smaller heads, unlike the large metal-on-metal articulation in our case, which is unique. CASE PRESENTATION: A 29-year-old male patient with juvenile idiopathic arthropathy presented to us with a fracture of the trunnion of his left THA, with no history of trauma. He had undergone staged bilateral THA for avascular necrosis of the hips 10 years ago (with AML-A stem and large metal-on-metal articulation bilaterally). We revised the THA and exchanged both femoral and acetabular components. He had a good functional outcome at 3 years' follow up. CONCLUSION: The primary reason for the trunnion fracture in our case was the faulty stem design of the AML [with a small (9/10) taper, and a large head], causing excessive bending moment at the trunnion, worsening the cantilever effect and leading to subsequent cyclic fatigue failure. Whilst gross trunnion failure (GTF) with dissociation of the head from the taper is commonly reported, trunnion fracture per se is a rare and devastating complication. The AML-A stem has since been recalled by the company and there is a need to constantly monitor these patients for potential trunnion-related complications.

MRI Evaluation of Post Core Decompression Changes in Avascular Necrosis of Hip.

INTRODUCTION: Avascular necrosis of hip typically presents in young patients. Core decompression in precollapse stage provides pain relief and preservation of femoral head. The results of core decompression vary considerably despite early diagnosis. The role of MRI in monitoring patients post surgically has not been clearly defined. AIM: To study pre and post core decompression MRI changes in avascular necrosis of hip. MATERIALS AND METHODS: This is a contiguous observational cohort of 40 hips treated by core decompression for precollapse avascular necrosis of femoral head, who had a baseline MRI performed before surgery. Core decompression of the femoral head was performed within 4 weeks. Follow up radiograph and MRI scans were done at six months. Harris hip score preoperatively, 1 month and 6 months after the surgery was noted. Success in this study was defined as postoperative increase in Harris hip score (HHS) by 20 points and no additional femoral collapse. End point of clinical adverse outcome as defined by fall in Harris hip score was conversion or intention to convert to total hip replacement (THR). MRI parameters in the follow up scan were compared to the preoperative MRI. Effect of core decompression on bone marrow oedema and femoral head collapse was noted. Results were analysed using SPSS software version. RESULTS: Harris hip score improved from 57 to 80 in all patients initially. Six hips had a fall in Harris hip score to mean value of 34.1 during follow up (9 to 12 months) and underwent total hip replacement. MRI predictors of positive outcome are lesions with grade A extent, Grade A & B location. Bone marrow oedema with lesions less than 50% involvement, medial and central location. CONCLUSION: Careful selection of patients by MR criteria for core decompression provides satisfactory outcome in precollapse stage of avascular necrosis of hip.

Anterior dislocation of hip following DHS fixation of intertrochanteric fracture: A case report.

Intertrochanteric fractures are commonly seen in elderly population. 90% of these occur following a trivial fall. Dynamic hip screw fixation is one of the most common modality of treatment, although intramedullary fixation devices are gaining popularity in recent times, especially in unstable fractures. Dislocation of hip following a DHS fixation of hip is a very rare complication. There are only two case reports which describes dislocation of hip following DHS fixation of an intertrochanteric fracture. Here we present a case of anterior dislocation of hip following DHS fixation of an intertrochanteric fracture. We also discuss about the possible causes of this rare complication, its management and follow up.

Posterior dislocation of meniscal bearing insert in mobile bearing unicompartmental knee arthroplasty mimicking a Baker cyst.

Unicompartmental knee arthroplasty (UKA) is a well-established procedure for isolated medial compartment osteoarthritis. Meniscal dislocation is a well-recognized complication in mobile bearing UKA especially when performed for the lateral compartment. Dislocation in medial UKA is relatively uncommon and is usually anterior when encountered. We would like to report a case of posterior dislocation of the bearing insert in a mobile bearing medial UKA presenting as a Baker cyst, which was subsequently revised to total knee arthroplasty.

Review: femoral tunnel placement for PCL reconstruction in relation to the PCL fibre bundle attachments.

Accurate placement of the femoral tunnel position is an important aspect of cruciate ligament reconstruction surgery. However, a wide range of positions have been described in the literature for the femoral tunnels for posterior cruciate ligament (PCL) reconstruction, and there is no consensus regarding the optimal placement. It was hypothesised that some of the prior studies used femoral PCL graft tunnels that were outside of the anatomical attachments. A systematic review and descriptive anatomical study in vitro were undertaken. Fifty articles that described PCL reconstruction since 1917 were reviewed; the description of the femoral tunnel placement was reproducible from only 20 of these. A right, distal femur was disarticulated and the PCL attachment was dissected; the centres of the anterolateral and posteromedial bundles were marked and confirmed to be close to the mean published data. The tunnel positions described in the 20 papers were also marked. The descriptions of 15 of the 20 anterolateral and 4 of the 5 posteromedial bundle tunnel centres were close (within +/-2 mm deep and +/-01:00 o'clock) to the anatomical centres of the bundle attachments. Other tunnels were placed either deeper or shallower than the anatomical attachments. The mean positions were: 7 mm from the articular cartilage at 1 o'clock for the anterolateral bundle, and 8 mm from the cartilage at 3 o'clock for the posteromedial bundle, in a right knee. It was concluded that it was not possible to replicate the tunnel positions used in most of the literature because of inadequate descriptions. Most of the usable descriptions of the anterolateral bundle position were close to the anatomical centre, but some tunnels were placed non-anatomically. A reproducible system for description of the femoral tunnel positions should be used.

A comparison of modified Larson and 'anatomic' posterolateral corner reconstructions in knees with combined PCL and posterolateral corner deficiency.

Different methods to reconstruct damaged posterolateral structures are available, but there has been little work studying their relative performance in combined PCL plus posterolateral corner (PLC) deficiency. We hypothesized that an 'anatomic' reconstruction with three graft bundles crossing the joint line would restore knee laxity closer to normal than a modified two-bundle Larson reconstruction. In a controlled laboratory study, the kinematics of cadaveric knees were measured electromagnetically with posterior drawer, external rotation, or varus rotation loads applied, with the knee at sequential stages: intact, PCL-deficient; PCL plus PLC-deficient; modified Larson reconstruction; anatomic PLC reconstruction. The graft bundles were tensioned sequentially to restore specific degrees of freedom to intact values of laxity at specific angles of knee flexion. A significant difference was not found between the two reconstructions. Both reconstructions restored external rotation and varus laxity to normal. Both restored posterior drawer to that caused by isolated PCL deficiency, but did not restore posterior laxity to normal. It was concluded that, with appropriate graft tensioning, both PLC reconstructions could restore both external rotation and varus laxity to normal, but not posterior drawer. The three-stranded anatomical reconstruction did not perform better than the modified two-strand Larson technique. Both of these isolated PLC reconstructions in knees with combined PCL plus PLC deficiency restored the knees to the laxity condition of an isolated PCL-deficiency, they could not reduce posterior drawer to normal.

Control of laxity in knees with combined posterior cruciate ligament and posterolateral corner deficiency: comparison of single-bundle versus double-bundle posterior cruciate ligament reconstruction combined with modified Larson posterolateral corner reconstruction.

BACKGROUND: Although many posterior cruciate ligament (PCL) injuries are in combination with posterolateral corner (PLC) injuries, there has been little research on combined injury reconstruction; the literature includes differing recommendations. HYPOTHESIS: Combined PCL plus PLC reconstruction corrects the abnormal posterior translation, varus, and external rotation laxities caused by combined PCL plus PLC deficiency. Furthermore, double-bundle PCL plus PLC reconstruction restores laxity closer to normal than single-bundle PCL plus PLC reconstruction. STUDY DESIGN: Controlled laboratory study. METHODS: Cadaveric knee kinematics were measured electromagnetically in 9 knees with posterior drawer, external rotation, and varus rotation loads applied at sequential stages: intact, PCL-deficient, PCL plus PLC-deficient, double-bundle PCL plus modified Larson PLC reconstruction, and single-bundle PCL plus modified Larson PLC reconstruction. Each graft was tensioned using a laxity-matching protocol. RESULTS: There was no significant difference between single-bundle and double-bundle PCL reconstruction, in combination with the modified Larson reconstruction, at any angle of flexion. Both combined reconstructions restored posterior drawer, external rotation, and varus laxity so that they did not differ significantly from normal. CONCLUSION: In combined PCL plus PLC deficiency, combined PCL plus PLC reconstruction restored all major laxity limits to normal across the range of knee flexion examined. Double-bundle PCL reconstruction was not better than single-bundle reconstruction in this context. CLINICAL RELEVANCE: The added complexity of double-bundle reconstruction does not seem to be justified by these results. In combined PCL plus PLC-deficient knees, combined single-bundle PCL plus modified Larson PLC reconstruction was sufficient to restore posterior drawer, external rotation, and varus laxity to normal.

Sudden loss of visual acuity following intra-articular steroid injection in to the knee joint: a case report.

BACKGROUND: Exogenous and endogenous steroids have been implicated in the pathogenesis of central serous choroioretinopathy in the literature. Central serous choroioretinopathy presents as sudden reduction in visual acuity. CASE PRESENTATION: Despite the fact that steroid injections are so commonly used in the Orthopaedics there is no information regarding central serous chorioretinopathy in Orthopaedic literature. We report a case of acute onset central serous chorioretinopathy following an intra-articular injection. CONCLUSION: Orthopaedic surgeons and doctors dealing with Musculoskeletal problems need to be aware of this unusual complication of systemic steroid therapy and refrain from administering further steroids to patients with history of blurring of vision or sudden loss of visual acuity following previous steroid injections.

Timing of tourniquet release in knee arthroplasty. Meta-analysis of randomized, controlled trials.

BACKGROUND: Some surgeons release the tourniquet before closing the wound to secure hemostasis during knee arthroplasty. We examined whether early tourniquet release could reduce the perioperative blood loss and whether not releasing the tourniquet until after wound closure would increase the risk of early postoperative complications. METHODS: We searched electronic databases and reference lists of relevant articles, retrieved all of the published randomized controlled trials designed to address these issues, and performed a meta-analysis. RESULTS: Eleven studies involving a total of 872 patients and 893 primary knee arthroplasties were analyzed systematically. The studies showed considerable clinical and methodological diversity. Early release of the tourniquet increased the total measured blood loss (weighted mean difference = 228.7 mL; 95% confidence interval = 168.3 to 289.1; p < 0.00001). Early release also increased blood loss as calculated on the basis of the maximum decrease in hemoglobin concentration (weighted mean difference = 320.7 mL; 95% confidence interval = 204.3 to 437.1; p < 0.00001). The rate of reoperations due to postoperative complications was 3.1% (nine of 290) in the group with late tourniquet release compared with 0.3% (one of 290) in the group with early tourniquet release; the risk difference was 3% (95% confidence interval, 0.1% to 5%), which was significant (p = 0.04). CONCLUSIONS: Early tourniquet release for hemostasis increases the blood loss associated with primary knee arthroplasty. However, tourniquet release after wound closure can increase the risk of early postoperative complications requiring another operation. Well-conducted large studies are needed to further explore the risk of early postoperative complications associated with late tourniquet release in knee arthroplasty. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions to Authors for a complete description of levels of evidence.

Late Streptococcus bovis infection of knee arthroplasty and its association with carcinoma of the colon: a case report.

Streptococcus bovis is a very rare cause of infection of joint arthroplasty. Infections with S. bovis have been reported to be associated with various gastrointestinal conditions. We present a case of total knee arthroplasty infected with S. bovis 40 months after a successful knee replacement. The diagnosis was established on joint fluid as well as blood cultures. Early diagnosis, arthroscopic wash out and appropriate antibiotics helped salvage the prosthesis. Early colonoscopy revealed carcinoma of the sigmoid colon that was surgically resected.

Quality of reporting of orthopaedic diagnostic accuracy studies is suboptimal.

Complete and accurate reporting of diagnostic research are essential to assess the validity of its results. To improve the quality of reporting of diagnostic accuracy studies, the Standards for Reporting of Diagnostic Accuracy (STARD) steering committee has developed a checklist of 25 items. We asked whether the quality of reporting of diagnostic accuracy studies published in three major orthopaedic journals (Clinical Orthopaedics and Related Research, Journal of Bone and Joint Surgery British Volume, and Journal of Bone and Joint Surgery American Volume) would be similar across levels of study, journals, and years of publication, and would be similar to other subspecialty journals. We identified 37 articles from 2002-2004 diagnostic accuracy studies and applied the STARD checklist and scoring system. The scores ranged from 6.6 to 21.4 with a mean of 15 +/- 3.3. Only 38% of the articles (14 of 37) reported more than 2/3 of the items, and the majority failed to report nine specific items. The mean STARD scores were similar between the studies with different levels of evidence, across the three journals, and across the three years of publication. They were similar to scores for other subspecialty journals. The current standards of reporting of diagnostic accuracy studies in orthopaedic journals are suboptimal.

Can peripheral nerve blocks contribute to heel ulcers following total knee replacement?

Peripheral nerve blocks are widely used for postoperative analgesia following total knee replacement. We would like to present three cases of heel ulcers encountered following a peripheral nerve block for knee replacement surgery. Postoperative heel ulcers have resulted in delayed rehabilitation in all three patients. Attention needs to be given to the pressure points in the foot after the nerve blocks. Awareness of this uncommon complication is necessary to prevent its occurrence.