Boys affected by Duchenne Muscular Dystrophy (DMD) often develop significant scoliosis in the second decade of life and require scoliosis surgery. Our aim was to establish whether cardiac MRI (CMR) improves the preoperative risk assessment in DMD patients and evaluate the current risk of surgery. Case records were retrospectively reviewed for 62 consecutive DMD boys who underwent pre-surgical evaluation at a single tertiary neuromuscular centre between 2008–2013. 62 DMD patients aged 7–18 years underwent pre-operative assessment for a total of 70 procedures (45 spinal, 19 foot, 6 gastrostomy). Echocardiography data were available for 68 procedures. Echo revealed a median left ventricular (LV) shortening fraction (SF) of 29% (range: 7–44). 34% of boys (23/68) had abnormal SF <25%, 48% (31/65) showed dyskinesia and 22% (14/64) had LV dilatation. CMR was routinely performed on 35 patients. Of those who underwent CMR, median left ventricular ejection fraction (LVEF) was 52% (range: 27–67%), 71% of boys (25/35) had dyskinesia. Echocardiography shortening fraction (SF) correlated significantly with CMR LVEF (rs = 0.67; p<0.001). Increasing severity of dyskinesia on CMR correlated with reduced CMR LVEF (rs = −0.64; p<0.001) and reduced echo SF (rs = −0.47; p = 0.004). Although functional echocardiography and CMR data tended to correlate in 35 DMD boys who underwent both imaging modalities nine (26%) had discrepant results. Seven (20%) had evidence of dysfunction on CMR (LVEF < 55%) not detected on echocardiography (SF ≥ 27%); in two cases echocardiogram measured worse function than CMR. Based on multi-disciplinary risk assessment, surgery was considered too high risk in 23 out of 67 (34%) cases. In 21 cases (91%) this was due to underlying cardiomyopathy. The highest risk among older boys assessed for spinal surgery; 21 out of 43 (49%). Of 19 boys undergoing spinal surgery, six (32%) experienced complications: two wound infections; three patients required readmission to intensive care; one patient died in the post-operative period with acute heart failure.
In the clinical trial, 58 consecutive patients undergoing total knee arthroplasty were included. After a routine exposure the AP axis was marked on each distal femur. The AFCL was then identified and the anterior femoral cortical cut was made parallel to this line. The angle between this cortical cut and the perpendicular to the AP axis was measured using a sterile goniometer. In the MRI study, 50 axial knee images were assessed and the most appropriate slice/s determined in order to identify the AFCL and the other 3 reference axes and then their relationship was measured by an on-screen goniometer.
By MRI and with respect to the epicondylar axis, the AFCL was a mean 5° externally rotated (SD= 3), White-side’s Line was 1° externally rotated (SD = 2) and the posterior condylar axis was 3° internally rotated (SD = 2). In the clinical study in 8 patients it was impossible to draw the AP axis because of dysplasia or destruction of the trochlea by osteoarthrosis. In the remainder the mean difference between the anterior femoral cortical line and Whiteside’s AP axis was 4.1 degrees internally rotated (SD = 3.8°). The lateral release rate for this cohort was 4%. Conclusion: The anterior femoral cortical line provides an additional reference point, completing the ‘compass points’ around the knee. It has been shown in this study to be reliable in the laboratory, on MRI and in a clinical setting for assessing rotation of the femoral component. It may prove particularly useful when one or all of the other reference axes are disturbed such as in revision TKR, lateral condylar hypoplasia or where there has been previous epicondylar trauma.
No patients have required revision of their components.
At 10 years, mean knee score was 174 with range of movement 0–111 degrees. 95.4% of the series has currently been successfully followed up. 9 patients were unable to be contacted and lost to follow up. With revision as an end point, the rate of survival for the prosthesis at 10 years is 99.4%. Assuming worst case scenario for patients lost to follow up, survivorship is 95.4%.
Although hydroxyapatite (HA) coating is known to enhance fixation in THR, its role in the fixation of Total Knee Replacements is less well appreciated. This study was performed to assess the medium-term results of an HA-coated TKR. Between August 1992 and 1998 all patients requiring a primary TKR were treated with a hydroxyapatite-coated, PCL-retaining prosthesis implanted by the senior author. The HA coating used was 70 microns thick with 75% crystallinity and 20% porosity. It is deposited on a beaded heat-sintered surface. A combined Hospital for Special Surgery and Knee Society Score was recorded pre-operatively and at three, six, 12, 24 and 60 months post-operatively. Fluoroscopically-controlled interface views were performed on the first 161 knees immediately post-operatively and repeated 24 months postoperatively. Six hundred and ninety two patients (Male:Female 335:357) with a mean age of 68 years (31–88 years) underwent 1 000 TKR mainly for OA (93%) and inflammatory arthropathies (RA 3%, psoriasis 1%). The mean follow up was 75 months (40–115). There were 461 unilateral (R:L 256:205) and 539 bilateral replacements (462 simultaneous and 77 staged). The pre-operative knee score was 95/200, ROM 6–115 degrees and at latest review was 182/200, ROM 1–113 degrees. Forty four patients have died (mean age 73 years, range 54 to 88). There have been 14 deep infections (1.4%), 22 proven pulmonary emboli (2.2%) and five periprosthetic fractures (0.5%). Six revisions have been performed. Visible gaps between bone and implant were present in 91% of femora and 58% of tibiae initially and in 6% of femora and 8% of tibiae at two years on interface views. There have been no cases of clinical loosening. Currently, this study comprises the largest known series of HA-coated total knee replacements. These results demonstrate that HA appears to enhance fixation of uncemented knee prostheses which maintain good clinical outcomes.
The purpose of study was to investigate kneeling ability after total knee replacement. 100 patients who were at least one year following routine uncemented primary total knee replacement were identified. 32% of patients stated they were able to kneel without significant discomfort. 64 (64%) of patients were actually able to demonstrate kneeling ability without pain or discomfort or with mild discomfort only. 24 (24%) of patients were therefore unable to demonstrate the ability to kneel because of discomfort in the knee. There was no difference in the “kneelers” and “non-kneelers” with regard to overall knee score, range of motion and the presence of patella resurfacing.