Slight femoral under-correction versus neutral alignment in total knee arthroplasty with preoperative varus knees: a comparative study

Background This study aimed to compare the short-term clinical results of slight femoral under-correction with neutral alignment in patients with preoperative varus knees who underwent total knee arthroplasty. Methods The medical records and imaging data were retrospectively collected from patients who had undergone total knee arthroplasty in our hospital from January 2016 to June 2019. All patients had varus knees preoperatively. Upon 1:1 propensity score matching, 256 patients (256 knees) were chosen and divided into a neutral alignment group (n=128) and an under-correction group (n=128). The patients in the neutral group were treated with the neutral alignment. In the under-correction group, the femoral mechanical axis had a 2° under-correction. The operative time, tourniquet time and the length of hospital stay in the two groups were recorded. The postoperative hip-knee-ankle angle, frontal femoral component angle and frontal tibial component angle were measured. Patient-reported outcome measures were also compared. Results The operative time, tourniquet time and the length of hospital stay in the under-correction group were significantly shorter than the neutral alignment group (P<0.05). At the 2-year follow-up, the under-correction group had a larger varus alignment (P<0.05) and a larger frontal femoral component angle (P<0.05), and the frontal tibial component angles of the two groups were comparable. Compared with the neutral alignment group, the slight femoral under-correction group had significantly better patient-reported outcome measures scores (P<0.05). Conclusion For varus knees treated with total knee arthroplasty, alignment with a slight femoral under-correction has advantages over the neutral alignment in terms of the shorter operative time and better short-term clinical results. Level of evidence III

Does robotic technology successfully restore the joint line after total knee arthroplasty? A retrospective analysis

Background Our study aims to determine the effectiveness of robotic technology for total knee arthroplasty in the successful restoration of the joint line of the knee with respect to that of a normal human anatomical knee. The restoration of the joint line is an important technical goal on which the postoperative outcomes and the success of the surgery depend. Methods Sixty-four postoperative plain anteroposterior radiographs of 60 patients, who received total knee arthroplasty by using the robotic technology were analyzed and compared with 66 similar radiographs of 60 patients who received the conventional method. The distances of the lateral epicondyle to the joint line (LEJL) and proximal tibiofibular joint to the joint line (PTFJJL) were calculated and analyzed. Results We found that the mean value of LEJL minus PTFJJL in the robotic group was 0.334 ± 0.115 (mean ± SD), while in the conventional group, it was 2.304 ± 0.308. The difference between the two groups was statistically significant. The mean ratio (LEJL:PTFJJL) in the robotic group was also equal to 1.017 ± 0.042. Conclusion From these findings it could be concluded that the robotic technology significantly increases the accuracy of the total knee arthroplasty and, compared to the conventional method, achieves an almost anatomical position of the joint line.

Obesity, preoperative weight loss, and telemedicine before total joint arthroplasty: a review

The preoperative period prior to elective total joint arthroplasty (TJA) is a critical time for lifestyle interventions since a scheduled surgery may help motivate patients to lose weight. Weight loss may reduce complications associated with obesity following TJA and enable patients with severe obesity (body mass index [BMI] > 40 kg/m2) to become eligible for TJA, as many institutions use a 40 kg/m2 cut-off for offering surgery. A comprehensive review was conducted to (1) provide background on complications associated with obesity following TJA, (2) synthesize prior research on the success rate of patients losing weight after being denied TJA for severe obesity, (3) discuss bariatric surgery before TJA, and (4) propose mobile health telemedicine weight loss interventions as potential weight loss methods for patients preoperatively.It is well established that obesity increases complications associated with TJA. In total knee arthroplasty (TKA), obesity increases operative time, length of stay, and hospitalization costs as well as the risk of deep infection, revision, and component malpositioning. Obesity may have an even larger impact on complications associated with total hip arthroplasty (THA), including wound complications and deep infection. Obesity also increases the risk of hip dislocation, aseptic loosening, and venous thromboembolism after THA.Synthesis of the only two studies (n = 417), to our knowledge, that followed patients denied TJA for severe obesity demonstrated that only 7% successfully reduced their BMI below 40 kg/m2 via lifestyle modifications and ultimately underwent TJA. Unfortunately, bariatric surgery may only increase certain post-TKA complications including death, pneumonia, and implant failure, and there is limited research on preoperative weight loss via lifestyle modification. A review of short-term mobile health weight loss interventions that combined personalized counseling with self-monitoring via a smartphone app found about 5 kg of weight loss over 3-6 months. Patients with severe obesity have more weight to lose and may have additional motivation to do so before TJA, so weight loss results may differ by patient population. Research is needed to determine whether preoperative mobile health interventions can help patients become eligible for TJA and produce clinically significant weight loss sufficient to improve postoperative outcomes.

The direct anterior approach to the hip: a useful tool in experienced hands or just another approach?

The direct anterior approach (DAA) to the hip was initially described in the nineteenth century and has been used sporadically for total hip arthroplasty (THA). However, recent increased interest in tissue-sparing and small incision arthroplasty has given rise to a sharp increase in the utilization of the DAA. Although some previous studies claimed that this approach results in less muscle damage and pain as well as rapid recovery, a paucity in the literature exists to conclusively support these claims. While the DAA may be comparable to other THA approaches, no evidence to date shows improved long-term outcomes for patients compared to other surgical approaches for THA. However, the advent of new surgical instruments and tables designed specifically for use with the DAA has made the approach more feasible for surgeons. In addition, the capacity to utilize fluoroscopy intraoperatively for component positioning is a valuable asset to the approach and can be of particular benefit for surgeons during their learning curve. An understanding of its limitations and challenges is vital for the safe employment of this technique. This review summarizes the pearls and pitfalls of the DAA for THA in order to improve the understanding of this surgical technique for hip replacement surgeons.

The mildly decreased preoperative bilirubin level is a risk factor for periprosthetic joint infection after total hip and knee arthroplasty

Background Many serologic markers are routinely tested prior to joint arthroplasty, but only few are commonly used to guide surgeons in determining patients most at risk of periprosthetic joint infection (PJI). The objective of this study was to investigate the association between preoperative bilirubin level and PJI after primary hip and knee arthroplasty. Methods A retrospective analysis was performed on patients undergoing revision hip and knee arthroplasty at our hospital from January 2016 to December 2019. Laboratory biomarkers were collected before the primary arthroplasty, as well as general patient information. The association between the above serologic markers and postoperative PJI was analyzed. Results A total of 72 patients (30 hips/42 knees) were analyzed, including 39 patients with PJI and 33 patients without PJI. Except for total bilirubin (TB) and direct bilirubin (DB), there was no significant difference between the remaining laboratory biomarkers. The preoperative TB and DB in the PJI group were 10.84 ± 0.61 μmol/L and 3.07 ± 0.19 μmol/L, respectively, which were lower than those in the non-PJI group (14.68 ± 0.75 μmol/L and 4.70 ± 0.39 μmol/L, P < 0.001). The area under the curve (AUC) of preoperative TB to predict PJI was 0.755 (P < 0.001, cutoff = 11.55 μmol/L, sensitivity = 66.67%, specificity = 75.76%). Meanwhile, the AUC of preoperative DB was 0.760 (P < 0.001, cutoff = 4.00 μmol/L, sensitivity = 84.62%, specificity = 54.45%). Conclusions The serum levels of TB and DB before the primary arthroplasty were lower in PJI patients than in non-PJI patients, and the preoperative values lower than 11.55 μmol/L and 4.00 μmol/L could be considered as a risk factor for postoperative PJI.

Coxiella burnetti prosthetic joint infection in an immunocompromised woman: iterative surgeries, prolonged ofloxacin-rifampin treatment and complex reconstruction were needed for the cure

Background Q fever is a zoonotic disease caused by the bacterium Coxiella burnetii, a strictly intracellular pathogen that can cause acute and chronic infection. Chronic Q fever can occur in immunocompetent as well as in immuno-compromised hosts, as a persistent localized infection. The main localizations are endocardial, vascular and, less frequently, osteoarticular. The most frequent osteoarticular form is spondyliscitis. Recommended treatment is combined doxycycline and hydroxychloroquine for 18 months, with cotrimoxazole as another option. Coxiella burnetti infection has been implicated in rare cases of prosthetic joint infection (PJI), and the medical and surgical management and outcome in such cases have been little reported. Case presentation We report an unusual case of chronic Q fever involving a hip arthroplasty in an immunocompromised woman treated with tumor necrosis factor (TNF)-α blockers for rheumatoid arthritis. Numerous surgical procedures (explantation, “second look”, femoral resection and revision by megaprosthesis), modification of the immunosuppressant therapy and switch from doxycycline-hydroxychloroquine to prolonged ofloxacin-rifampin combination therapy were needed to achieve reconstruction and treat the PJI, with a follow-up of 7 years. Conclusions Coxiella burnetti PJI is a complex infection that requires dedicated management in an experienced reference center. Combined use of ofloxacin-rifampin can be effective.

Short-term results of a novel management of supracondylar fracture with coexisting osteoarthritis with bifold fixation and total knee arthroplasty

Purpose Presence of supracondylar and periarticular femoral fracture with associated arthritis of knee poses a challenging situation to the orthopaedic surgeon. The results of fixation of fracture in osteoporosis are not very satisfactory and have complications. With fixation alone, they still cannot bear weight on affected leg due to severe disability of osteoarthritis. To make patient walk, conventionally three surgeries in the form of fracture fixation, removal of implant and total knee arthroplasty (TKA) needs to be done in staged manner. We propose a novel management in form of bifold fixation and simultaneous TKA. Methods Eight cases (6 females, 2 males) of supracondylar femoral fractures with severe osteoarthritis of the knee and osteoporosis were primarily fixed with bifold fixation using SIGN nail (www.signfracturecare.org) and locking plate together with simultaneous total knee arthroplasty. There were five cases (2 males and 3 females) of grade 4 (Kellgren-Lawrence grading) osteoarthritis (OA) and three cases (all females) of severe rheumatoid arthritis (RA). Results The mean age was 68 years and average time for full weight bearing was 6 days. Radiographic evidence of fracture union was achieved in 16.25 weeks. The mean Knee Society Score (KSS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score at 26 months was 83.13 and 22.13 respectively. Conclusions Single stage combined bifold osteosynthesis with interlocking nail and locking plate together with total knee arthroplasty helps in one time management of these difficult injuries. It is a cost-effective and economically sound option and gives excellent results with good patient satisfaction.

Equivalent VTE rates after total joint arthroplasty using thromboprophylaxis with aspirin versus potent anticoagulants: retrospective analysis of 4562 cases across a diverse healthcare system

Background Guidelines support aspirin thromboprophylaxis for primary total hip and knee arthroplasty (THA and TKA) but supporting evidence has come from high volume centers and the practice remains controversial. Methods We studied 4562 Medicare patients who underwent elective primary THA (1736, 38.1%) or TKA (2826, 61.9%) at 9 diverse hospitals. Thirty-day claims data were combined with data from the health system’s electronic medical records to compare rates of venous thromboembolism (VTE) between patients who received prophylaxis with: (1) aspirin alone (47.3%), (2) a single, potent anticoagulant (29%), (3) antiplatelet agents other than aspirin or multiple anticoagulants (21.5%), or (4) low-dose subcutaneous unfractionated heparin or no anticoagulation (2.2%). Sub-analyses separately evaluating THA, TKA and cases from lower volume hospitals (n = 975) were performed. Results The 30-day VTE incidence was 0.6% (29/4562). VTE rates were equal in patients receiving aspirin and those receiving a single potent anticoagulant (0.5% in both groups). Patients with VTE were significantly older than patients without VTE (mean 76.5 vs. 73.1 years, P = 0.04). VTE rate did not associate with sex or hospital case volume. On bivariate analysis considering age, aspirin did not associate with greater VTE risk compared to a single potent anticoagulant (OR = 2.1, CI = 0.7–6.3) with the numbers available. Odds of VTE were increased with use of subcutaneous heparin or no anticoagulant (OR = 6.4, CI = 1.2–35.6) and with multiple anticoagulants (OR = 3.6, CI = 1.1–11.2). THA and TKA demonstrated similar rates of VTE (0.5% vs. 0.7%, respectively, P = 0.43). Of 975 cases done at lower volume hospitals, 387 received aspirin, none of whom developed VTE. Conclusions This study provides further support for aspirin as an effective form of pharmacological VTE prophylaxis after total joint arthroplasty in the setting of a multi-modal regimen using 30-day outcomes. VTE occurred in 0.7% of primary joint arthroplasties. Aspirin prophylaxis did not associate with greater VTE risk compared to potent anticoagulants in the total population or at lower volume hospitals.

After 25 years of computer-navigated total knee arthroplasty, where do we stand today?

Background Limb and implant alignment along with soft tissue balance plays a vital role in the outcomes after total knee arthroplasty (TKA). Computer navigation for TKA was first introduced in 1997 with the aim of implanting the prosthetic components with accuracy and precision. This review discusses the technique, current status, and scientific evidence pertaining to computer-navigated TKA. Body The adoption of navigated TKA has slowly but steadily increased across the globe since its inception 25 years ago. It has been more rapid in some countries like Australia than others, like the UK. Contemporary, large console-based navigation systems help control almost every aspect of TKA, including the depth and orientation of femoral and tibial resections, soft-tissue release, and customization of femoral and tibial implant positions in order to obtain desired alignment and balance. Navigated TKA results in better limb and implant alignment and reduces outliers as compared to conventional TKA. However, controversy still exists over whether improved alignment provides superior function and longevity. Surgeons may also be hesitant to adopt this technology due to the associated learning curve, slightly increased surgical time, fear of pin site complications, and the initial set-up cost. Furthermore, the recent advent of robotic-assisted TKA which provides benefits like precision in bone resections and avoiding soft-tissue damage due to uncontrolled sawing, in addition to those of computer navigation, might be responsible for the latter technology taking a backseat. Conclusion This review summarizes the current state of computer-navigated TKA. The superiority of computer navigation to conventional TKA in improving accuracy is well established. Robotic-assisted TKA provides enhanced functionality as compared to computer navigation but is significantly more expensive. Whether robotic-assisted TKA offers any substantive advantages over navigation is yet to be conclusively proven. Irrespective of the form, the use of computer-assisted TKA is on the rise worldwide and is here to stay.

The application of close incisional negative pressure wound therapy in revision arthroplasty among asian patients: a comparative study

Introduction Peri-prosthetic joint infection (PJI) was one of the main causes of revision of arthroplasty. In order to reduce wound complications and surgical site infections, close incisional negative pressure wound therapy (ciNPWT) has been introduced into arthroplasty. This study was designed to review the clinical benefits of the application of ciNPWT in revision arthroplasty. Methods This was a single-centre retrospective comparative study approved by the Institutional Review Board. Patients, who underwent revision total knee arthroplasty or revision total hip arthroplasty at the author’s institution from January 2016 to October 2019, were included in this study. The ciNPWT cohort included all eligible patients, who underwent operations from January 2018 to October 2019, with the use of ciNPWT(n = 36). The control cohort included all eligible patients, who underwent operations from January 2016 to December 2017 with the use of conventional dressing(n = 48). The incidences of wound complications were compared to both cohorts. Results There was a statistically significant difference in the rate of superficial surgical site infection (SSI) between control cohort and ciNPWT cohort (12.5% in control vs 0% in ciNPWT, p = 0.035). However, there was no statistically significance of the overall wound complication rate for both cohorts. (14.6% in control vs 8.3% in ciNPWT, p = 0.504). Conclusions The application of ciNPWT could result in a lower rate of superficial surgical site infection when compared with conventional dressing among the patients undergoing revision total knee and total hip arthroplasties. Trial registration UW19-706