Two-Stage Primary Arthroplasty in the Infected Native Knee: A Systematic Review and Pooled Analysis.

INTRODUCTION: The knee is the commonest native joint to develop an infection. A two-stage primary knee replacement, with an interim stage of debridement and cement spacer application, modelled after two-stage revision for periprosthetic joint infections (PJI) has been reported for the management of chronic infections. AIMS: To systematically review the literature to find the infection-free survival and outcomes of this operation and explore its indications. METHODS: PRISMA guidelines were followed for this review. A systematic search of 4 online databases was conducted on 9/8/2020. After reviewing 226 abstracts and applying our selection criteria, 10 papers were selected for full-text review, and 9 included in the final synthesis. RESULTS: On pooled analysis, an infection-free survival of 95.6% (CI 94.7-96.4) was found at 2 years in 139 knees, which was unchanged over the remainder of the follow-up (Mean 3.9 years). The complication rate after final implantation was 6% in those that did not develop reinfection. The mean pooled Knee Society Score (KSS) and KSS Function score among 70 patients (4 papers) was 83.4 (80.1-89.0) and 76.8 (71.5-78.0), respectively. The mean range of motion among 82 patients (6 papers) was more than 100°. CONCLUSIONS: Two-stage primary knee replacement is a safe, effective and reliable procedure with good results in the short to medium term. Further studies are required to lay down precise indications and cost-effectiveness of this procedure, in comparison to other strategies for chronic infection. All joint registries should develop methods to identify patients undergoing two-stage procedures, to understand their long-term survival and outcomes.

Stacked Tantalum Cones as a Method for Treating Severe Distal Femoral Bone Deficiency in Total Knee Arthroplasty.

Severe bone loss in distal femur has traditionally been managed with bulk cementing, bone graft, metal augments, trabecular metal cones, and mega prosthesis. The authors present an alternative method using a stacked configuration of two tantalum cones to manage severe distal femoral bone loss. This study aims to evaluate the mid-term outcomes and possible complications in patients treated with this novel technique. We retrospectively analyzed the prospectively maintained records of 16 knees (in 16 patients) presenting with severe distal femoral bone deficiency due to septic loosening (5), giant cell tumor (GCT; 4), periprosthetic fracture (3), aseptic loosening (3), and distal femoral comminuted fracture with severe osteoarthritis (1). A standard medial parapatellar approach was taken in all our cases followed by preparation of distal femoral bone defect and use of two bridging tantalum trabecular metal cones to fill the defect, followed by implantation of rotating hinge knee prosthesis. At an average follow-up of 57 months (4.75 years), the average Knee Society Score was 74.56 (64-87) and the mean range of motion was 97.8 (70-120) degrees. Radiologically, all 16 knees showed good osteointegration with no evidence of progressive radiolucency or loosening. Complications included two patients with superficial infection (healed with antibiotics), and one with recurrence of GCT requiring tumor megaprosthesis reconstruction. The authors concluded that the stacked configuration of cones provides additional coverage and stability with good osteointegration and found it to be particularly useful in distal femoral GCTs and fracture situations. They recommend the use of stacked cones in selected cases of severe distal femoral deficiency.

Management Options in Avascular Necrosis of Talus.

Avascular necrosis (AVN) of the talus can be a cause of significant disability and is a difficult problem to treat. The most common cause is a fracture of the talus. We have done a systematic review of the literature with the following aims: (1) identify and summarize the available evidence in literature for the treatment of talar AVN, (2) define the usefulness of radiological Hawkins sign and magnetic resonance imaging in early diagnosis, and (3) provide patient management guidelines. We searched MEDLINE and PUBMED using keywords and MESH terminology. The articles' abstracts were read by two of the authors. Forty-one studies met the inclusion criteria of the 335 abstracts screened. The interventions of interest included hindfoot fusion, conservative measures, bone grafting, vascularized bone graft, core decompression, and talar replacement. All studies were of Level IV evidence. We looked to identify the study quality, imprecise and sparse data, reporting bias, and the quality of evidence. Based on the analysis of available literature, we make certain recommendations for managing patients of AVN talus depending on identified disease factors such as early or late presentation, extent of bone involvement, bone collapse, and presence or absence of arthritis. Early talar AVN seems best treated with protected weight bearing and possibly in combination with extracorporeal shock wave therapy. If that fails, core decompression can be considered. Arthrodesis should be saved as a salvage procedure in late cases with arthritis and collapse, and a tibiotalocalcaneal fusion with bone grafting may be needed in cases of significant bone loss. Role of vascularized bone grafting is still not defined clearly and needs further investigation. Future prospective, randomized studies are necessary to guide the conservative and surgical management of talar AVN.

Does Prior Failed Debridement Compromise the Outcome of Subsequent Two-Stage Revision Done for Periprosthetic Joint Infection Following Total Knee Arthroplasty?

BACKGROUND: There has been a debate regarding the outcomes of 2-stage revision total knee arthroplasty (TKA) when debridement, antibiotics, irrigation, and implant retention (DAIR) had been carried out previously. The purpose of this study is to evaluate the influence of prior failed DAIR (F-DAIR) on the outcomes of 2-stage revision TKA done for periprosthetic joint infection (PJI). METHODS: This is a retrospective study of a consecutive series of 184 knees that completed 2-stage revision TKA for PJI, operated by a single surgeon between January 2000 and July 2011. The cohort was divided into 2 groups: (1) with previous F-DAIR (88 knees) and (2) direct 2-stage revision (96 knees). RESULTS: At an average follow-up of 5.3 years, the failure rate was 23.86% (21/88 knees) in the F-DAIR group and 15.62% (15/96) in the direct 2-stage revision group. Prior F-DAIR procedure was associated with approximately twice the risk of failure compared to direct 2-stage surgery (hazards ratio 1.94, 95% confidence interval 1.01-3.714, P = .047). Excluding PJIs caused by methicillin-resistant Staphylococcus aureus, methicillin-resistant Staphylococcus epidermidis, and Pseudomonas from analysis revealed similar failure rates between the 2 groups. The Knee Society Clinical Score, Knee Society Functional Score, and final range of motion at final follow-up were lower in the F-DAIR group. Incidence of culture negativity and infection with resistant organisms was higher in the F-DAIR group. The rates of eradication of methicillin-resistant Staphylococcus aureus and Pseudomonas infection were much lower in the F-DAIR group. CONCLUSION: A failed prior DAIR results in higher failure rates, lower functional outcome, and increased risk of wound-related complications.

Early failure with massive metallosis and posteromedial wear following atraumatic anterior cruciate ligament rupture after medial unicompartmental knee arthroplasty.

Severe metallosis following medial unicompartmental knee arthroplasty (UKA) is relatively rare. It is usually due to long-standing wear of the polyethylene component, resulting in frictional wear between the femoral and tibial metallic components. Biomechanical and cadaveric studies have shown the effects of anterior cruciate ligament (ACL) transection following medial UKA. We describe a case of a 58-year-old male who developed attritional rupture of the ACL 16 months following medial UKA leading on to early accelerated failure over the next 8 months. The patient underwent revision to total knee arthroplasty with good outcome. The clinical effect of spontaneous ACL transection on medial UKA causing abnormal posteromedial wear of polyethylene component and tibial tray, massive metallosis, and worsening of mechanical axis can be demonstrated in this case report.

Unusual Salmonella typhi periprosthetic joint infection involving bilateral knees: management options and literature review.

A 70-year-old Indian woman, who had undergone primary bilateral total knee arthroplasty (TKA) for rheumatoid arthritis 10 months prior, presented with 10 days history of pain, swelling and erythema over both knees with pus discharging from the right knee. She had type 2 diabetes mellitus and was on long-term steroid, leflunomide and antitumour necrosis factor therapy for rheumatoid arthritis. Her clinical and laboratory features were suggestive of a haematogenous periprosthetic joint infection (PJI). The final diagnosis of bilateral Salmonella typhi PJI was made based on culture reports. Considering her underlying immunosuppression, a bilateral two-stage revision TKA was done with complete remission of symptoms and good functional recovery at last follow-up after 18 months. S. typhi infection of prosthetic joint has not been reported in the literature. Patients presenting with gastrointestinal complaints and PJI should alert the clinician to the possibility of infection with such atypical organisms endemic to the region.

A Comparative Study on the Long-Term Outcome of Total Knee Arthroplasty Performed for Knees Stiff in Extension and Those Stiff in Flexion.

BACKGROUND: Patients with chronic stiff knee with extremely restricted arc of motion (AOM ≤ 20°) may present with stiffness either in extension (stiff in extension [SE]) or in flexion (stiff in flexion [SF]). The difference in the functional outcome after total knee arthroplasty between these 2 groups has not been elaborated in literature. METHODS: We retrospectively analyzed 96 patients (115 knees), who had undergone total knee arthroplasty between January 1990 and December 2010 for stiff or spontaneously ankylosed knees (AOM ≤ 20°). This included 51 knees in SE group and 64 knees in SF group. RESULTS: The average duration of follow-up was 9.7 years (2-17.5 years). The total AOM improved from an average of 10.9° ± 7.4° preoperatively to 86.5° ± 13.5° postoperatively in SE group and 8.7° ± 6.8° to 92.2° ± 16.8° in the SF group. The mean Knee Society Score in the SE group improved from 23.2 ± 5.7 preoperatively to 74.1 ± 8.9 postoperatively and that of SF group from 14 ± 5.2 to 71.2 ± 12.5. At 3 months follow-up, Knee Society Score for SE group were higher than that for SF group (P = .03). This difference was not noted beyond 1 year. Complications were noted in 24 (20.9%) knees-10 (23.5%) in SE group and 14 (21.9%) in SF group. CONCLUSION: The maximum mean AOM achieved was higher in SF group but the incidence of residual flexion contracture was also higher as compared to SE group. The long-term functional outcome scores in SE and SF groups are similar.

Functional Results of Communited Intra-articular Distal Humerus Fractures Treated with Bicolumnar Plating.

INTRODUCTION: Communited intra-articular distal humerus fractures are commonly encountered in orthopaedic practice and they are present with unique difficulties for internal fixation. This problem is especially worse in the elderly due to osteoporotic bone. AIM: To evaluate the intermediate term results (minimum follow up of two years) of communited intra-articular distal humerus fractures treated with bicolumnar plating with or without olecranon osteotomy in elderly Indian population. MATERIALS AND METHODS: Sixty three consecutive patients operated with bicolumnar plating for communited intra-articular distal humerus fractures at the tertiary care centre were identified in the time period between 2009 and 2013. All patients had an age more than 60 years at the time of surgery. A minimum follow up of two years post surgery was a mandatory criteria. The Disabilities of Arm and Shoulder and Hand (DASH) score and the Mayo Elbow Performance (MEP) score calculated along with complete range of motion. RESULTS: The mean follow-up was 38 months. All patients achieved fracture union with mean MEP and DASH scores being 85 ± 15.5 and 21.4 ± 4.9 respectively. These scores although poor were comparable to the opposite side (90 and 12.2 respectively). Also the mean supination-pronation arc and flexion-extension arc was 156 degrees and 105 degrees respectively. This is well within the functional range of elbow. The mean block to extension was at 15 degrees with a mean maximal flexion of 120 degrees. CONCLUSION: Our study conclusively establishes that excellent functional outcome can be achieved with open reduction and internal fixation in Type C distal humerus fractures in elderly including the ones that are communited. Total elbow arthroplasty although a viable option, gives similar results to a well done internal fixation with added cost.