Native Knee Joint Research Articles

Behandlung der Strecksehnenruptur bei liegender Knietotalendoprothese

Disruption of the extensor mechanism is one of the most devastating complications in knee arthroplasty with a reported incidence between 0.17 and 2.5 %. Due to a high rate of subsequent complications and poor clinical results, every effort should be made to avoid extensor mechanism disruption. In cases of disruption however, the orthopaedic surgeons must be aware of non-operative and surgical treatment options and their indications, timing, outcome and limitations. Non-operative treatment is feasible in cases of incomplete disruption of the quadriceps tendon with an extension deficit of less than 20°. Complete disruption of the quadriceps tendon or rupture of the patellar tendon should be treated operatively. Therapeutic strategies include direct repair of the tendon in acute disruption without retraction. Retraction as well as soft tissue damage necessitates augmentation of the tendon. Frequently used endogenous augments are the semitendinosus tendon as well as the gastrocnemius muscle. Exogenous options are allografts of the Achilles tendon or structured extensor mechanism grafts and synthetic augments to support endogenous tendon repair. The clinical results after extensor mechanism failure following total knee arthroplasty are less favourable compared to ruptures in native knee joints. The most common complications are postoperative stretching and the maintenance of an active extensor lag.

Patellofemoral Arthritis

Patellofemoral arthroplasty represents a modern surgical treatment for patients with isolated patellofemoral arthritis. This procedure is less invasive than total knee arthroplasty and preserves the patients' ligaments, menisci, and most of their native knee joint. Even though it raised much controversy in its early days due to poor results, newer-generation implants have led to lower complications rates and improved outcomes. This is mainly owing to the use of onlay implants, which truly replace the patellofemoral compartment. Thorough patient selection is crucial to optimize outcomes. Progression of arthritis in the tibiofemoral compartments currently constitutes the most frequently seen complication. Recent advances include the use of computer navigation and the combination of patellofemoral arthroplasty with other minimally invasive procedures to address more extensive disease of the knee joint.

High tibial osteotomy: evolution of research and clinical applications—a Canadian experience

This narrative review describes experiences at the Fowler Kennedy Sport Medicine Clinic (FKSMC) with high tibial osteotomy (HTO) for patients with varus gonarthrosis, with particular focus on research published from the unit that has guided practice. The goals of surgery are to improve alignment of the weight bearing axis of the lower limb to lessen the load on the medial tibiofemoral compartment and thereby decrease these important risk factors for disease progression. The overall aims are to improve knee function and delay or even prevent the eventual need for arthroplasty. To achieve these aims, a medial opening wedge osteotomy is utilised, deliberately avoiding an over correction of the lower limb, but tailoring the angle of correction to an individual patient's characteristics. With such an approach, patients with a broad range of characteristics (including age, BMI and lateral compartment involvement) can benefit from the procedure. In addition, the HTO can be used with concomitant procedures to address specific presentations, such as large deformities and instability. The results suggest that correction to a slight valgus alignment produces approximately 50% reduction in medial compartment loads during gait with large, clinically important improvements in patient-reported outcomes at 2-years postoperatively. In patients with substantial bilateral varus deformity, unilateral surgery can lead to increased dynamic knee joint loads on the nonoperative limb after surgery. This means that such patients require the close monitoring of both limbs and consideration of a staged, bilateral procedure if necessary. In patients requiring bilateral surgery, similar results after bilateral HTO to those after unilateral surgery have been reported. For patients requiring large corrections, the need for a concomitant tibial tubercle osteotomy to reduce the potential for iatrogenic patella infera is considered. Finally, HTO procedures can also be used in patients with instability, either to alter both sagittal and coronal alignment to correct instability in complex ligament deficiencies or to undertake simultaneous HTO and ACL reconstruction. HTO is being used both alone and in conjunction with concomitant procedures with good clinical results. While continued investigation into patient selection and outcomes are required, current research indicates that HTO offers at least a partial solution for the patient with varus gonarthrosis to prolong the life of their native knee joint. V.

Septic arthritis of the knee: the use and effect of antibiotics prior to diagnostic aspiration

Septic arthritis of the native knee joint and total knee arthroplasty both cause diagnostic and treatment issues. There is no gold standard test to diagnose a joint infection and the use of joint aspiration is commonly relied on. It is widely accepted by orthopaedic surgeons that antibiotics should be withheld until aspiration has been performed to increase the odds of identifying an organism. Patients often present to other specialties that may not be as familiar with these principles.Our study found that 25 (51%) of the 49 patients treated for septic arthritis of the native or prosthetic knee in our unit over a 3-year period had received antibiotics prior to discussion or review by the on-call orthopaedic service. Patients were significantly less likely to demonstrate an organism on initial microscopy (entire cohort: p=0.001, native knees: p=0.006, prosthetic knees: p=0.033) or on subsequent culture (entire cohort: p=0.001, native knees: p=0.017, prosthetic knees: p=0.012) of their aspirate if they had received antibiotics. The sensitivity of microscopy in all patients dropped from 58% to 12% when patients had received antibiotics (native knees: 46% to 0%, prosthetic knees: 72% to 27%). The sensitivity of the culture dropped from 79% to 28% in all patients when the patient had received antibiotics (native knees: 69% to 21%, prosthetic knees: 91% to 36%).This study demonstrated how the management of patients with suspected cases of septic arthritis of the knee may be compromised by empirical administration of antibiotics. These patients were significantly less likely to demonstrate an organism on microscopy and culture of their initial aspirate. There is a significant high false negative rate associated with knee aspiration with prior administration of antibiotic therapy.

Refractory Arthrographis kalrae native knee joint infection

Rare reports of infection with Arthrographis kalrae have often demonstrated a protracted clinical course. We describe refractory infection of the native knee with Arthrographis kalrae after a penetrating injury and Yttrium synovectomy, finally controlled with two stage joint revision and combination antifungal therapy. The paucity of worldwide data about such uncommon invasive fungal infections contributes to the diagnostic and therapeutic challenges of these cases.

Prosthetic Knee Infection in the Young Immigrant Patient—Do Not Forget Tuberculosis!

Skeletal tuberculosis (TB) frequently masquerades as more common etiologies and can be difficult to diagnose. We describe a case of TB knee arthritis in a young Haitian-born woman in whom the diagnosis was not initially suspected, resulting in treatment with total knee arthroplasty that subsequently failed. A long course of medical and surgical therapies was then necessary to treat this patient. Issues in the diagnosis and management of TB in the native and prosthetic knee joint are presented.

Arthroplasty following a septic arthritis history: A 53 cases series

The most feared complication of arthroplasty after septic arthritis (active or quiescent) on a degenerative joint is septic failure, but this risk is difficult to assess. The aim of the present study was to analyze the results of arthroplasties after septic arthritis of native knee and hip joints, in terms of functional results and infection control and to seek eventual risk factors of failure. Fifty-three cases of septic arthritis treated by arthroplasty (31 knees and 22 hips) were retrospectively included. In case of evolutive septic arthritis (30 cases: 17 knees and 13 hips) failing to react to conservative treatment, arthroplasty was performed in a 2-stage procedure (a mean interval of 6 weeks between stages, and an associated antibiotic therapy for a mean 3 months were routinely respected). In case of previous arthritis considered to be cured (23 cases: 14 knees and nine hips), arthroplasty was performed with a 1-stage procedure, observing a mean interval of 5 years after the initial septic arthritis, and antibiotic therapy maintained until definitive microbiological results were obtained from joint cultures samples at surgery. No patients were lost to follow-up; minimum follow-up was 2 years, for a mean of 5 years. The final results were assessed in terms of functional outcome (on PMA functional score for hips and IKS score for knees) and successful eradication of infection. Two-stage arthroplasty was successful in 26 of the 30 cases of evolutive septic arthritis (87%), while the 1-stage procedure was successful in 22 of the 23 cases of quiescent septic arthritis (95%) (NS). Functional results were very good. No significant difference in functional outcome or successful eradication of infection was found between the 1- and 2-stage procedures. No significant difference in final outcome in terms of infection eradication was found between knees and hips. No clinical, microbiological or treatment-related criteria emerged as risk factors for septic failure. Arthroplasty after septic arthritis of the knee or hip using the present protocol (2-stage implantation in case of evolutive septic arthritis and a 1-stage procedure in case of quiescent septic arthritis) achieved very good functional results with a success rate of 87% for sepsis control in evolutive septic arthritis and of 95% in quiescent septic arthritis. Level IV retrospective or historical series.