The Knee
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A 62year old man developed a compartment syndrome of the thigh after total knee arthroplasty. Twelve years previously he had a HTO of the same knee complicated by a compartment syndrome of the calf. ⋯ Compartment syndrome of the thigh is a rare, but potentially devastating, complication following total knee arthroplasty. A previous compartment syndrome of the calf is identified as a risk factor.
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Varus thrust is an abnormal lateral knee motion frequently seen in patients with medial knee osteoarthritis (OA) during gait. It is a worsening of the alignment in the stance phase of the gait cycle and closely relates to disease progression. In this study, we measured the thrust quantitatively using skin markers and examined the relationship to other static and dynamic parameters. ⋯ The amounts of thrust in subjects with K-L grades 2 (25 knees), 3 (13 knees), and 4 (6 knees) were 2.4°(±1.3°), 2.8°(±1.4°), and 7.2°(±5.3°), respectively and the knee adduction moments were 3.6(±1.5) %BW⁎Ht, 3.9(±1.2) %BW⁎Ht and 6.9(±2.2%) BW⁎Ht, respectively. The amount of thrust also exhibited significant correlation to static radiographic alignment (R=0.47: 95% confidence interval 0.67-0.21, p=0.0038) and showed greater correlation to the knee adduction moment (R=0.73: 95% confidence interval 0.84-0.55, p<0.001), which has been identified as an important dynamic index of the disease. The amount of thrust, which is able to be measured by simple inexpensive equipment, correlated to static and dynamic parameters and may offer an important clinical index for knee OA.
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We present two case reports with clinical and radiological assessment of the anatomical features at the distal lateral end of trochlea and femur in patients with patellar instability in higher knee flexion and how these findings could possibly be involved in the genesis of this rare type of patellar instability. Both patients underwent several (nine and seven) surgical procedures, but the patellar instability could not be successfully eliminated. Our hypothesis was that a short and flattened lateral distal condyle/trochlea may cause lateral patellar instability in higher flexion. ⋯ With these procedures, lateral patellar instability with increased flexion could be completely eliminated in both patients at the 1- and 2-year follow-up. Our experience of assessment and treatment of these patients let us conclude that variations of the distal lateral femoral condyle/trochlea morphology may be responsible for patellar instability with increased flexion. This is another type of patellar instability caused by distal condyle/trochlea dysplasia compared to the well known and often described types of patellar instability close to extension caused by proximal trochlea dysplasia.
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Case Reports
Successful treatment of wound breakdown caused by pyoderma gangrenosum after total knee arthroplasty.
Pyoderma gangrenosum is a rare ulcerative disorder of the skin of unknown etiology. We present a case of pyoderma gangrenosum that occurred following total knee arthroplasty, which was initially misdiagnosed as severe wound infection. ⋯ Pyoderma gangrenosum is often misdiagnosed as an infected wound, but the treatment for theses differential diagnoses is completely different. When a lesion is refractory to thorough treatment for infection, a diagnosis of pyoderma gangrenosum should be considered.
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Randomized Controlled Trial
A randomised controlled trial investigating the effect of posterior capsular stripping on knee flexion and range of motion in patients undergoing primary knee arthroplasty.
Increasing knee flexion following total knee arthroplasty (TKA) has become an important outcome measure. Surgical technique is one factor that can influence knee motion. In this study, it was hypothesised that stripping of the posterior knee capsule could improve flexion and range of motion (ROM) following TKA. ⋯ There were no significant difference in the rate of complications. Posterior capsular stripping causes a transient increase in flexion that does not persist post-operatively. We do not recommend routine stripping of the posterior knee capsule in patients undergoing TKA.