Robotic-arm assisted total knee arthroplasty is associated with comparable functional outcomes but improved forgotten joint scores compared with conventional manual total knee arthroplasty at five-year follow-up.

PURPOSE: This study reports the five-year functional outcomes from a prospective cohort study comparing robotic-arm assisted total knee arthroplasty (RO TKA) versus conventional manual total knee arthroplasty (CO TKA). METHODS: This prospective single-surgeon study included 120 patients with symptomatic end-stage knee arthritis undergoing primary TKA. This included 60 consecutive patients undergoing CO TKA followed by 60 consecutive patients undergoing RO TKA using a semi-automated robotic device. Study patients were reviewed at one, two, and five years after surgery and the following outcomes recorded: The University of California at Los Angeles activity-level (UCLA), Knee Society Score (KSS), Oxford Knee Score (OKS) Forgotten Joint Score (FJS), and any complications. RESULTS: There were no statistical differences between RO TKA and CO TKA in the median UCLA score (p = N.S), median KSS (p = N.S), and median OKS (p = N.S) at five-year follow-up. RO-TKA was associated with statistically significant improvements in the FJS at one (p = 0.001), two (p = 0.003), and five (p = 0.025) years of follow-up compared with CO TKA. There was no statistical difference in the incidence of knee stiffness requiring manipulation under anesthesia between the two treatment groups (p = N.S). CONCLUSION: Patients in both treatment groups had excellent functional outcomes with comparable patient reported outcomes at five-year follow-up. RO TKA was associated with statistically significant improvements in the FJS compared with CO TKA, but these differences did not reach the minimal clinically important difference at any follow-up interval. There was no overall difference in complications between the two treatment groups at five-year follow-up. LEVEL OF EVIDENCE: II (Prospective cohort study).

The evolution of patellofemoral prosthetic design in total knee arthroplasty: how far have we come?

Total knee arthroplasty (TKA) has evolved into a successful, cost-effective treatment for end-stage knee arthrosis.The patellofemoral articulation in TKA has largely been ignored during its development despite being an important determinant of outcome.New technologies still need further development to incorporate the patella in TKA surgical planning and operative technique.Alternative approaches to alignment in TKA will have a secondary impact on patellofemoral mechanics and possibly future implant designs.Technologies that assist with precise implant positioning may alter our understanding and overall practice of TKA. Cite this article: EFORT Open Rev 2019;4:503-512. DOI: 10.1302/2058-5241.4.180094.

Randomised controlled trial of triclosan coated vs uncoated sutures in primary hip and knee arthroplasty.

BACKGROUND: Triclosan-coated vicryl plus suture (Ethicon, Inc.) was developed to reduce microbial colonisation during surgical procedures. However, its effect on wound healing and surgical site infections remain unclear after hip and knee arthro-plasty surgery. AIM: To determine the effect of triclosan-coated sutures (TCS) vs non-coated sutures on wound healing, following primary hip and knee arthroplasties. METHODS: A single-centred, double-blind randomised controlled trial (RCT) was undertaken. We randomly allocated patients to receive either the triclosan-coated sutures (TCS vicryl plus) or non-coated sutures (NCS vicryl) during the closure of unilateral primary hip and knee arthroplasties. We utilised the ASEPSIS wound scoring system to evaluate wound healing for the first 6 weeks post-operatively. RESULTS: One hundred and fifty patients undergoing primary total hip or knee arthroplasty over a one-year period were included. Eighty-one were randomised to the TCS group and 69 to the NCS group. Despite no statistically significant difference in the ASEPSIS scores among the study groups (P = 0.75), sensitivity analysis using the Mann Whitney test (P = 0.036) as well as assessment of the wound complications at 6 weeks follow up, demonstrated significantly higher wound complication rates in the TCS group (8 vs 1, P = 0.03). CONCLUSION: No clear advantage was demonstrated for using the TCS. However, larger multi-centred RCTs are required to validate their use in hip and knee arthroplasty surgery.

Periprosthetic joint infections after total hip replacement: an algorithmic approach.

An algorithm for managing periprosthetic joint infections (PJIs) after total hip replacement (THR) surgery using a multidisciplinary approach and a clearly defined protocol may improve infection eradication rates. In this article, we present an algorithm for the management of different types of PJIs including the acutely infected cemented and cementless THRs where the components are well-fixed postoperatively and when the infection is secondary to haematogenous spread in previously well-functioning and well-fixed implants. For chronic PJIs where the components are often loose, the standard treatment includes a two-stage revision procedure. However, in a highly selected subset of patients, a single-stage approach has been utilised with high rates of eradicating infections.

Two-stage Revision for Periprosthetic Hip and Knee Joint Infections.

BACKGROUND: Periprosthetic joint infection (PJI) continues to be one of the leading causes of failure following hip and knee surgery. The diagnostic workflow of PJI includes detailed clinical examination, serum markers, imaging and aspiration/biopsy of the affected joint. The goals of treatment are eradication of the infection, alleviation of pain, and restoration of joint function. Surgical management of PJI consists of debridement, antibiotics and implant retention (DAIR) and single or two-stage revision procedures. Two-stage revision remains the gold standard for treatment of PJIs. We aim to discuss the two stage procedure in this article and report the outcomes. METHODS: The first stage of the two stages consists of removal of all components and associated cement with aggressive debridement and placement of an antibiotic-loaded cement spacer. Patients are then treated with variable periods of parenteral antibiotics, followed by an antibiotic free period to help ensure the infection has been eradicated. If the clinical evaluation and serum inflammatory markers suggest infection control, then the second stage can be undertaken and this involves removal of the cement spacer, repeat debridement, and placement of a new prosthesis. RESULTS: Common themes around the two-stage revision procedure include timing of the second stage, antibiotics used in the interim period, length of the interim period before consideration of reimplantation and close liaising with microbiologists. CONCLUSION: Successful eradication of infection and good functional outcome using the two stage procedure is dependent on a multidisciplinary approach and having a standard reproducible startegy.

One-stage Exchange Arthroplasty for Periprosthetic Hip and Knee Joint Infections.

BACKGROUND: Periprosthetic joint infection (PJI) is a devastating complication of joint replacement surgery. In an aging population of the developed world, the increasing numbers of hip and knee replacements will inevitably lead to increasing incidence of PJI, carrying with (it) significant patient morbidity and cost to the health care system. Two-stage exchange arthroplasty is currently the gold standard but it is associated with multiple operations, prolonged hospitalization and impaired functionality. One-stage exchange arthroplasty is similar to the two-stage procedure but the interval between removal of the prosthesis and reimplantation of a new one is only a few minutes. It has the theoretical benefits of a single anesthetic, shorter hospitalization, less cost and improved function. METHODS: We reviewed the current literature regarding the outcomes of one-stage exchange arthroplasties focusing on re-infection rates and functional outcomes. RESULTS: Current themes around the one-stage exchange procedure include the indications for the procedure, definition of re-infection, surgical techniques used to provide fixation and differences in approach for hip and knee replacements. CONCLUSION: The current literature on one-stage exchange procedure is promising, with comparable results to two-stage revisions for hips and knees in selected patients. However, there is a great need for a large multi-centred randomized control trial, focusing on re-infection rates and functional scores postoperatively, to provide concrete guidelines in managing this complex condition.

Definition of Periprosthetic Hip and Knee Joint Infections and the Economic Burden.

Periprosthetic Joint infection (PJI) following hip and knee replacements is an important complication causing major concern for patients, operating surgeons and healthcare systems. Therefore, a standardized definition of PJI is required to improve communication and allow for valid comparisons of various diagnostic and treatment strategies. This review summarizes the most commonly used definitions for PJI and the current consensus. It also highlights the economic burden related to PJIs and the importance of a multidisciplinary approach to managing those infections.

Aggressive Early Debridement in Treatment of Acute Periprosthetic Joint Infections After Hip and Knee Replacements.

BACKGROUND: Periprosthetic Joint Infection Remains a Dreaded Complication After Hip and Knee Replacement Surgery. Treatment Options for Acute Postoperative and Acute Hematogenous Infections Include Arthroscopic or Open Debridement With Retention or Exchange of the Prostheses. This Review Article Aims to Summarize the Evidence for Management of Acute Postoperative And Acute Hematogenous Infections. METHODS: A Systematic Literature Search Was Performed Using a Computer-based Search Engine Covering Medline (OvidSP), PubMed Database (U.S. National Library of Medicine, National Institutes of Health), Embase, Web of Science, Cochrane and Google Scholar for Relevant Articles. RESULTS: Common Themes Around Treatment of Acute Postoperative and Acute Hematogenous Infections Discussed in this Review Include the Timing of Intervention, Description of the Optimal Procedure and How we Perform it at our Institution, the Role of Arthroscopic Debridement, Most Commonly Isolated Micro-organisms and Prognostic Factors for Infection Control. CONCLUSION: Success in Treating Acute Postoperative and Acute Hematogenous Infections Depends on Early Diagnosis and Aggressive Surgical Debridement Combined With Effective Antibiotic Therapy.

Biofilm and the Role of Antibiotics in the Treatment of Periprosthetic Hip and Knee Joint Infections.

An increasing demand for lower limb arthroplasty will lead to a proportionate increase in the need for revision surgery. A notable proportion of revision surgery is secondary to periprosthetic joint infections (PJI). Diagnosing and eradicating PJI can form a very difficult challenge. An important cause of PJI is the formation of a bacterial biofilm on the implant surface. Our review article seeks to describe biofilms; their definitions and formation, common causative bacteria, prophylactic and therapeutic antibiotic therapy.

Is single-stage revision according to a strict protocol effective in treatment of chronic knee arthroplasty infections?

BACKGROUND: The increasing number of patients experiencing periprosthetic total knee arthroplasty (TKA) infections and the cost of treating them suggest that we seek alternatives to two-stage revision. Single-stage revision is a potential alternative to the standard two-stage procedure because it involves only one surgical procedure, so if it is comparably effective, it would be associated with less patient morbidity and lower cost. QUESTIONS/PURPOSES: We compared (1) the degree to which our protocol of a highly selective single-stage revision approach achieved infection control compared with a two-stage revision approach to TKA infections; and (2) Knee Society scores and radiographic evidence of implant fixation between the single-stage and two-stage patients who were treated for more complicated infections. METHODS: Between 2004 and 2009, we treated 102 patients for chronic TKA infections, of whom 28 (27%) were treated using a single-stage approach and 74 (73%) were treated using a two-stage approach. All patients were available for followup at a minimum of 3 years (mean, 6.5 years; range, 3-9 years). The indications for using a single-stage approach were minimal/moderate bone loss, the absence of immunocompromise, healthy soft tissues, and a known organism with known sensitivities for which appropriate antibiotics are available. Participants included 38 men and 64 women with a mean age of 65 years (range, 45-87 years). We used the Musculoskeletal Infection Society definition of periprosthetic joint infection to confirm infection control at the last followup appointment. Radiographs were evaluated for signs of loosening, and patients completed Knee Society Scores for clinical evaluation. RESULTS: None of the patients in the single-stage revision group developed recurrence of infection, and five patients (93%) in the two-stage revision group developed reinfection (p=0.16). Patients treated with a single-stage approach had higher Knee Society scores than did patients treated with the two-stage approach (88 versus 76, p<0.001). However, radiographic findings showed a well-fixed prosthesis in all patients with no evidence of loosening at last followup in either group. CONCLUSIONS: Our data provide preliminary support to the use of a single-stage approach in highly selected patients with chronically infected TKAs as an alternative to a two-stage procedure. However, larger, multicenter, prospective trials are called for to validate our findings. LEVEL OF EVIDENCE: Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Aggressive early débridement for treatment of acutely infected cemented total hip arthroplasty.

BACKGROUND: Up to 2% of THAs are complicated by infection, leading to dissatisfied patients with poor function and major social and economic consequences. The challenges are control of infection, restoration of full function, and prevention of recurrence. Irrigation and débridement with or without exchange of modular components remains an attractive alternative to two-stage reimplantation in acutely infected THAs but with variable results from previous studies. QUESTIONS/PURPOSES: We therefore determined the rate at which aggressive early débridement with exchange of modular components controlled acutely infected cemented THAs. METHODS: We retrospectively studied all 26 patients presenting with acutely infected cemented THAs (16 primaries, 10 revisions) occurring within 6 weeks of the index operation or of hematogenous spread from a confirmed source of infection elsewhere between 1999 and 2006. Microbiology confirmed bacterial colonization in all patients, with 18 early postoperative infections and eight acute hematogenous infections. Patients underwent aggressive débridement with open complete synovectomy, exchange of all mobile parts, débridement of all aspects of the joint, irrigation with antiseptic solutions, and pulsatile lavage. Minimum followup was 5 years (mean, 6.6 years; range, 5-11 years). RESULTS: Eight patients had multiple washouts with control of infection in four at latest followup. Five patients underwent two-stage revisions and one patient was placed on long-term antibiotic suppression. Twenty patients returned to their expected functional level with no radiographic evidence of prosthetic failure. At minimum 5-year followup, we had a 77% infection control rate. CONCLUSIONS: Our data confirm current literature and suggest there may be a role for aggressive early débridement in controlling acute postoperative and hematogenous infections after cemented THA. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Knee arthroplasty with a medially conforming ball-and-socket tibiofemoral articulation provides better function.

BACKGROUND: A knee design with a ball-and-socket articulation of the medial compartment has a femoral rollback profile similar to the native knee. Compared to a conventional, posterior-stabilized knee design, it provides AP stability throughout the entire ROM. However, it is unclear whether this design difference translates to clinical and functional improvement. QUESTIONS/PURPOSES: We asked whether the medially conforming ball-and-socket design differences would be associated with (1) improved ROM; and (2) improved American Knee Society, WOMAC, Oxford Knee, SF-36, and Total Knee Function Questionnaire scores compared to a conventional, fixed-bearing posterior-stabilized TKA. PATIENTS AND METHODS: We enrolled 82 patients in a single-center, single-blinded, randomized, controlled trial comparing the medially conforming ball-and-socket design knee prosthesis to a posterior-stabilized total knee prosthesis. Our primary end point was ROM. Our secondary end points were American Knee Society, WOMAC, Oxford Knee, SF-36, and Total Knee Function Questionnaire scores. All patients were followed at 1 and 2 years. RESULTS: The mean ROM was 100.1° and 114.9° in the posterior-stabilized and medially conforming ball-and-socket groups, respectively. The physical component scores of SF-36 and Total Knee Function Questionnaire were better in the medially conforming ball-and-socket group. We found no difference in American Knee Society, WOMAC, and Oxford Knee scores. CONCLUSIONS: Both implant designs similarly relieved pain and improved function. The medially conforming ball-and-socket articulation provided better high-end function as reflected by the Total Knee Function Questionnaire. LEVEL OF EVIDENCE: Level I, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Midterm assessment of causes and results of revision total knee arthroplasty.

BACKGROUND: There is limited information regarding revision total knee arthroplasty (TKA) with respect to etiology, outcome, and long-term survival comparing different implant types. QUESTIONS/PURPOSES: We compared patient outcomes, survivorship and modes of failure and the most common etiologic factors for rerevision between different revision implant types. METHODS: We retrospectively reviewed 349 cases of revision TKA in 343 patients whose mean age was 67.8 years. Three implant types were used: posterior stabilized, condylar constrained knee, and rotating hinge. The etiologies included infection (32.7%), aseptic loosening (14.9%), and polyethylene wear (12.3%). The minimum followup was 12 months (mean, 57.7 months; range, 12-120 months). RESULTS: The mean Knee Society scores were 89 (range, 48-94), 88.9 (range, 45-95), and 84 (range, 56-94) and the mean ranges of motion were 110.0 degrees (range, 70 degrees -125 degrees ), 106.1 degrees (range, 70 degrees -120 degrees ), and 111.7 degrees (range, 85 degrees -125 degrees ) for the posterior stabilized, condylar constrained knee, and rotating hinge types, respectively. The rotating hinge group had the highest satisfaction rates (88%). Overall 10-year survivorship was 90.6% with highest survivorship seen in the rotating hinge group. The most common causes for rerevision were infection (2.9% of our cohort), instability (1.7%), and aseptic loosening (1.4%). The mean overall time to rerevision was 69.9 months (range, 11-119 months). CONCLUSIONS: In our experience periprosthetic infection is the most common cause of failure of both primary and revision TKA. Functional outcome and range of motion improve irrespective of revision implant type. The rotating hinge prosthesis provides patient satisfaction and survivorship similar to that of other implant types. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Femoral fracture following knee ligament reconstruction surgery due to an unpredictable complication of bioabsorbable screw fixation: a case report and review of literature.

We report an unusual case of femoral fracture from minimal trauma, due to the rapid disappearance of a bioabsorbable interference screw used for reconstruction of the posterolateral corner of the knee. The literature on bone tunnel fractures following knee ligament reconstruction surgery is also reviewed.

Do physical diagnostic tests accurately detect meniscal tears?

Numerous physical tests have been described but their diagnostic accuracy is often questioned. Karachalios et al. described the new 'Thessaly test' and concluded that it could be safely used as a first line screening test for the selection of patients who need arthroscopic meniscal surgery. Our objective was to study the role of physical diagnostic tests in screening for meniscal tears and to validate the diagnostic accuracy of the Thessaly test. We examined 109 patients (80 male, 29 female; average age: 39 years; range: 16-56) who were presented with a history suggestive of a meniscal tear. Joint line tenderness, McMurray's test, and the Thessaly test were assessed by an independent investigator blinded to any imaging data in all patients. MRI and subsequent arthroscopy results were then collated. Our study showed a much lower diagnostic accuracy for the Thessaly test (61% for medial meniscus and 80% for lateral meniscus). It is comparable to McMurray's test (57% for medial meniscus and 77% for lateral meniscus). The Joint line tenderness test has a far superior diagnostic accuracy (81% for medial meniscus and 90% for lateral meniscus). However, combining the joint line tenderness test with McMurray's test or the joint line tenderness test with Thessaly test further increased the accuracy of physical diagnosis of meniscal tears. Magnetic resonance imaging (MRI) detected 96% of meniscal tears. Physical tests may not always be diagnostic of meniscal tears. MRI and arthroscopy may be essential in dubious clinical presentations and especially where more than one pathology is suspected. Our study showed that the Thessaly test in isolation was not useful for the detection of meniscal tears but it helps to increase diagnostic certainty when combined with other standard tests.

The unpredictable material properties of bioabsorbable PLC interference screws and their adverse effects in ACL reconstruction surgery.

The aim of this study was to look at the clinical outcome of polylactide carbonate (PLC) interference screws in knee ligament reconstruction surgery. We prospectively followed up 59 patients who underwent primary hamstring anterior cruciate ligament (ACL) reconstructions using PLC (Calaxo screw; Smith and Nephew, Andover, MA) screws to secure the graft in the tibial tunnel. The average age was 34 years (range 17-55 years, SD 8.93). Twenty-three (39%) patients presented with complications [synovitis in 15% (nine) patients, prominent tibial swelling in 34% (20) patients and both in seven patients]. In comparison, similar complications were not seen in two groups of 59 age and sex matched patients in whom PLLA (Bio RCI; Smith and Nephew, Andover, MA) screws or Titanium (RCI; Smith and Nephew, Andover, MA) screws were used by the same surgeon. The problems encountered in the PLC screw group did not adversely affect knee stability. Six patients underwent exploration of the tibial tunnel site. A sterile white cheesy substance was removed, leaving an empty tibial tunnel. The ACL graft was found to be well attached to tibial tunnel in all cases. The PLC screw diameter, surface area or tibial tunnel diameter did not have any correlation to the occurrence of complications. Two patients required multiple washouts, one of whom developed a deep infection. The degradation of PLC screws does not follow the gradual and controlled pattern demonstrated in the ovine model. The unpredictable screw degradation, and the reaction to it can lead to serious clinical consequences.