In vivo roughening of retrieved total knee arthroplasty femoral components.

BACKGROUND: Joint registry data highlights the higher rates of cumulative revision for younger patients undergoing TKR. One of the reasons associated with this higher revision rate may be due to the wear of the UHMWPE leading to loosening. Alternate bearing surfaces have been developed to address this problem; however, roughening of the metal bearing surface has not been demonstrated in vivo. METHOD: We recorded roughness measurements of retrieved femoral components. RESULTS: Average lateral condyle roughness was 0.032 µm, compared to control values of 0.020 µm, p=0.002; average medial condyle roughness was 0.028 µm, compared to a control value of 0.019, p<0.001. CONCLUSION: There was a small but statistically significant roughening of femoral components in vivo compared to controls. This may have important implications for aseptic loosening of knee arthroplasty components and the decision to use scratch resistant components.

How Effective are Lateral Wedge Orthotics in Treating Medial Compartment Osteoarthritis of the Knee? A Systematic Review of the Recent Literature.

Lateral wedges were originally proposed to manage medial compartment osteoarthritis of the knee but recent reviews suggest that lateral wedges do not affect disease progression. We performed a systematic review to analyse the recent literature and define how effective, if at all, lateral wedges are in the management of medial compartment osteoarthritis of the knee. The inclusion criteria were defined as any study published within the last decade, using a sample size of at least twenty patients, and investigating the effect of insoles or wedges on either unilateral or bilateral knee varus osteoarthritis. The standardised keyword term 'lateral*wedge*OR insole*OR orthotic* OR medial compartment OR varus OR osteoarthri* OR knee*' was used. We identified 10 studies that fitted our inclusion criteria. Although there is not enough evidence in the literature to prove that lateral wedge orthotics are an effective treatment for varus osteoarthritis of the knee, there is some evidence to suggest that they do have some symptomatic effect. Patients with early osteoarthritis and higher BMI may benefit to a greater extent than those with a greater extent of degenerative changes and lower BMI. The literature is unclear as to what the optimal duration for the use of lateral wedges is, but does support the prolonged use of the wedges as the benefits at one month are maintained at one year. Future studies should be randomised controlled trials with a large sample size with long follow-up, and use objective clinical, biomechanical and radiological outcome measures.

Review article: Plica syndrome of the knee.

Plica syndrome is a pathological condition secondary to inflammation. Plicae around the knee are common and generally asymptomatic. They often are misdiagnosed. The morphology of knee plicae varies; mediopatellar plicae are the most common cause of the plicae syndrome. An intermittent dull pain is the most common symptom. Diagnosis is made by exclusion. Ultrasonography is useful; arthroscopy is the gold standard. Arthroscopic removal of the plica may be necessary when conservative treatment for up to 6 months fails.

Recent advances in designs, approaches and materials in total knee replacement: literature review and evidence today.

Ever since Themistocles Gluck described the use of an ivory cup as a tibial hemiarthroplasty in 1894, knee arthoplasty has continued to evolve. Both human ingenuity and intensive clinical research has led to an improved understanding of biomaterials and knee kinematics, resulting in the modern total knee replacement which has enjoyed such a clinical and commercial success. As it increases in popularity, attempts to improve knee arthroplasty have been driven by demands for improved function and implant survival, particularly in younger, more demanding patients. Research continues to see if advances in implant instrumentation, materials and design will translate into improved clinical outcomes and longevity.

Synovial hypertrophy causing recurrent hemarthrosis after total knee replacement.

Recurrent hemarthrosis following total knee replacement is relatively uncommon and can result from causes that may not always be easy to diagnose. We report three patients with late-onset recurrent hemarthrosis following total knee replacement due to synovial hypertrophy and impingement, which were successfully treated by embolization.

A conservative approach to quadricepsplasty: description of a modified surgical technique and a report of three cases.

Various techniques have been described for the treatment of soft tissue extension contracture of the knee. Some involve large exposures, and others can result in a permanent extensor lag. We describe a technique with limited exposure, avoiding transverse incisions in the rectus femoris. Through a midline incision, the extensor expansion is exposed. The rectus femoris is separated from the vastus medialis, lateralis, and intermedius to form a strap-like structure. Vastus intermedius is separated from the patella. If firm, careful manipulation of the knee is unsuccessful, the incisions are extended distally along both sides of the patella and patellar tendon, releasing the extensor mechanism from any underlying heterotopic bone, and further manipulation of the knee is performed. Postoperatively, a rehabilitation program is begun. A good outcome following this technique is described in 3 knees presenting with severe restriction of knee flexion. There were no wound complications and no residual extensor lag.

Delayed surgical intervention for a severe fixed flexion deformity of the knee following anterior cruciate ligament reconstruction.

We report a case of severe fixed flexion deformity of the knee, following anterior cruciate ligament (ACL) reconstruction, due to protrusion of the bone block and fixation screw into the knee joint above the tibial tunnel. This was treated successfully after a latent period of 6 years with surgical intervention. This case highlights the importance of critical review of radiographic imaging when faced with a fixed flexion deformity of the knee after ACL surgery and the ability to achieve a good outcome from simple surgical intervention even after a long latent period.

Standardized mortality ratios and fatal pulmonary embolism rates following total knee replacement: a cohort of 936 consecutive cases.

Mortality and fatal pulmonary embolism rates in 936 consecutive primary total knee replacements (TKR) were determined during a 3-month postoperative period. Postmortem examinations verified the cause of death in all but 3 patients, and follow-up was performed on all but 1 patient. All patients had elastic stockings as mechanical prophylaxis. No deaths occurred from pulmonary embolism confirmed by postmortem examinations. At worst, the fatal pulmonary embolism rate was 0.43% (4/936; confidence interval [CI]=0.14%-1.17%). The all-cause mortality rate was 0.64% (6/936; CI=0.26%-1.46%). The patient mortality was compared with the population mortality of England and Wales using standardized mortality ratios. The standardized mortality ratios for both sexes combined was 0.74 (CI=0.29-1.52). A lower mortality was observed in women (0.67) than in men (0.84) during the first 3 postoperative months compared to the general population. Fatal pulmonary embolism after TKR with the routine use of graded elastic stockings and early mobilization is rare. In this series, the death rate in patients undergoing TKR appears to be lower than that in the general population.