The aticularis genu (AG) is the least substantial and deepest muscle of the anterior compartment of the thigh and of uncertain significance. The aim of the study was to describe the anatomy of AG in cadaveric specimens, to characterize the relevance of AG in pathological distal femur specimens, and to correlate the anatomy and pathology with preoperative magnetic resonance imaging (MRI) of AG. In 24 cadaveric specimens, AG was identified, photographed, measured, and dissected including neurovascular supply. In all, 35 resected distal femur specimens were examined. AG was photographed and measured and its utility as a surgical margin examined. Preoperative MRIs of these cases were retrospectively analyzed and assessed and its utility assessed as an anterior soft tissue margin in surgery. In all cadaveric specimens, AG was identified as a substantial structure, deep and separate to vastus itermedius (VI) and separated by a clear fascial plane with a discrete neurovascular supply. Mean length of AG was 16.1 cm ( ± 1.6 cm) origin anterior aspect distal third femur and insertion into suprapatellar bursa. In 32 of 35 pathological specimens, AG was identified (mean length 12.8 cm ( ± 0.6 cm)). Where AG was used as anterior cover in pathological specimens all surgical margins were clear of disease. Of these cases, preoperative MRI identified AG in 34 of 35 cases (mean length 8.8 cm ( ± 0.4 cm)).Aims
Methods
Vascularised fibular grafts (VFGs ) are a valuable
surgical technique in limb salvage after resection of a tumour.
The primary objective of this multicentre study was to assess the
risk factors for failure and complications for using a VFG after
resection of a tumour. The study involved 74 consecutive patients (45 men and 29 women
with mean age of 23 years (1 to 64) from four tertiary centres for
orthopaedic oncology who underwent reconstruction using a VFG after
resection of a tumour between 1996 and 2011. There were 52 primary
and 22 secondary reconstructions. The mean follow-up was 77 months
(10 to 195). In all, 69 patients (93%) had successful limb salvage; all of
these united and 65 (88%) showed hypertrophy of the graft. The mean
time to union differed between those involving the upper (28 weeks;
12 to 96) and lower limbs (44 weeks; 12 to 250). Fracture occurred
in 11 (15%), and nonunion in 14 (19%) patients. In 35 patients (47%) at least one complication arose, with a
greater proportion in lower limb reconstructions, non-bridging osteosynthesis,
and in children. These complications resulted in revision surgery
in 26 patients (35%). VFG is a successful and durable technique for reconstruction
of a defect in bone after resection of a tumour, but is accompanied
by a significant risk of complications, that often require revision
surgery. Union was not markedly influenced by the need for chemo-
or radiotherapy, but should not be expected during chemotherapy.
Therefore, restricted weight-bearing within this period is advocated. Cite this article:
Techniques for the selective cutting of ligaments in cadaver knees defined the static contributions of the posterolateral structures to external rotation, varus rotation and posterior tibial translation from 0° to 120° of flexion under defined loading conditions. Sectioning of the popliteofibular ligament (PFL) (group 1) produced no significant changes in the limits of the knee movement studied. Sectioning of the PFL and the popliteus tendon (femoral attachment, group 2) produced an increase of only 5° to 6° in external rotation from flexion of 30° to 120° (p <
0.001). Even when other ligaments were sectioned first (group 3), the maximum effect of the PFL was negligible. Our findings show that the popliteus muscle-tendon-ligament complex, lateral collateral ligament, and posterolateral capsular structures function as a unit. No individual structure alone is the primary restraint for the movements studied. Operative reconstruction should address all of the posterolateral structures, since restoration of only a portion may result in residual instability.
Before proceeding to longer-term studies, we have studied the early clinical results of a new mobile-bearing total knee prosthesis in comparison with an established fixed-bearing device. Patients requiring bilateral knee replacement consented to have their operations under one anaesthetic using one of each prosthesis. They also agreed to accept the random choice of knee (right or left) and to remain ignorant as to which side had which implant. Outcomes were measured using the American Knee Society Score (AKSS), the Oxford Knee Score (OKS), and determination of the range of movement and pain scores before and at one year after operation. Preoperatively, there was no systematic difference between the right and left knees. One patient died in the perioperative period and one mobile-bearing prosthesis required early revision for dislocation of the meniscal component. At one year the mean AKSS, OKS and pain scores for the new device were slightly better (p <
0.025) than those for the fixed-bearing device. There was no difference in the range of movement. We believe that this is the first controlled, blinded trial to compare early function of a new knee prosthesis with that of a standard implant. It demonstrates a small but significant clinical advantage for the mobile-bearing design.
