In Total Knee Replacement, over-sizing the femoral component may restrict knee flexion. If the AP dimension of the existing femur is in between component sizes, you should down-size the femoral component whenever possible. Using the Triathlon Knee System the femoral and tibial component sizes were recorded for 140 consecutive knee replacements. For each procedure, the femoral component size was compared to the tibial component size and recorded as same size, one size down or one size up. The author’s component selection was then compared with 500 Triathlon knee replacements carried out during the same period by other surgeons In the authors 140 cases, the femoral component was the same size in 96(68%), one size down in 33(24%) and one size up in 11(8%). This compared with other users (500 cases) where the femoral component was the same size in 360(62%), one size down in 51(10%) and one size up in 89(18%). Compared with other users, the author was more likely to downsize the femoral component 24% v 18% and less likely to upsize 8% v 18%. These differences were significant, p<
0.05.
The purpose of this study was to investigate the mechanism of injury causing anterior cruciate ligament ruptures in snowboarders and skateboarders. Knee injuries in snowboarding and skateboarding are rare. We have seen 22 ACL ruptures with an identical injury mechanism that has not been previously described. Fifteen ACL ruptures occurred in snow-boarders and 7 in skateboarders. All were advanced or expert boarders. All injuries occurred on landing a high jump, which resulted in significant knee compression. All described a flat landing on a flexed knee with no twisting component. We postulate that anterior cruciate ligament rupture in these patients is due to explosive eccentric quadriceps contraction when landing from a jump. The injury mechanism is not boot induced as has been described in downhill skiers landing from a jump.
To describe a simple effective technique of opening wedge tibial osteotomy for the treatment of recurvatum (hyperextension) instability of the knee. Recurvatum instability of the knee occurs in patients with pathological hyperextension. There are three patterns of recurvatum instability:-
Acquired bony deformity of the proximal tibia (growth plate arrest or fracture malunion) Pathological laxity of the posterior capsule of the knee. This may occur without damage to the cruciate ligaments. A combination of bony and soft tissue pathology All three patterns are best treated by an opening wedge tibial osteotomy at the level of the tibial tubercle. A simple surgical technique is described that does not require detachment of the tibial tubercle. The necessary degree of correction is easily assessed clinically during surgery. The technique has been used with success in 8 patients. The Puddu tooth plate provides ideal fixation. Iliac crest cortico-cancellous wedge bone grafts have been used in all cases.
Radial cleavage tears of the lateral meniscus are uncommon and may be associated with a meniscal cyst. There is a recognised association of these lesions with radiographically visible erosions of the lateral tibial plateau; however, this association is reported to be rare. We believe this radiographic feature is more common than previously reported and as most reports are limited to the radiology literature it is not widely appreciated by Orthopaedic Surgeons. The aim of this study was to determine the prevalence of this valuable radiographic sign in patients with a proven radial cleavage tear and draw attention to it among Orthopaedic Surgeons. We identified 20 patients from our prospectively collected database that had undergone an arthroscopic partial lateral meniscectomies for radial cleavage tears of the lateral menisci. A consultant radiologist (NS) independently assessed the pre-operative radiographs of these patients, specifically looking for the presence of erosions of the tibiae below the lateral joint line. Of 20 patients assessed 9(45%) had radiographically visible bone erosions. Our study confirms our clinical experience that patients with symptoms and signs suggestive of a radial cleavage tear of the lateral meniscus frequently have an associated plain radiographic sign to support the clinical diagnosis.