To compare the effect of femoral bone tunnel configuration on tendon-bone healing in an anterior cruciate ligament (ACL) reconstruction animal model. Anterior cruciate ligament reconstruction using the plantaris tendon as graft material was performed on both knees of 24 rabbits (48 knees) to mimic ACL reconstruction by two different suspensory fixation devices for graft fixation. For the adjustable fixation device model (Socket group; group S), a 5 mm deep socket was created in the lateral femoral condyle (LFC) of the right knee. For the fixed-loop model (Tunnel group; group T), a femoral tunnel penetrating the LFC was created in the left knee. Animals were sacrificed at four and eight weeks after surgery for histological evaluation and biomechanical testing.Objectives
Methods
We aimed to evaluate the temperature around the nerve root during drilling of the lamina and to
determine whether irrigation during drilling can reduce the chance of nerve root injury. Lumbar nerve roots were exposed to frictional heat by high-speed drilling of the lamina in a live
rabbit model, with saline (room temperature (RT) or chilled saline) or without saline (control)
irrigation. We measured temperatures surrounding the nerve root and made histological
evaluations.Aims
Materials and Methods
The purpose of this study was to evaluate in vivo fit and fill analysis of tapered wedge-type stem in total hip arthroplasty (THA) with computed tomography (CT)-based navigation system. 100 THAs were all performed through the posterolateral approach, with patients in the lateral decubitus position. Each cohort of 50 consecutive primary cementless THAs with was compared with and without CT-based navigation system. The post-operative antero-posterior (AP) hip radiographs were obtained two weeks after the operation. All radiographic fit and fill measurements in the proximal and distal areas were analyzed by two of the authors who were both blinded to the use of CT-based navigation system. The type of the fit in the cementless stem was divided into three types. The fit of the stem was classified as Type I, if there was both proximal and distal engagement (maximum proximal to distal engagement difference of 2 mm or greater), Type II when there was proximal engagement only, and Type III when there was distal engagement only. The fill parameters such as mean stem-to-canal ratios and mean minimum and maximum gaps between the stems to the cortical bone in proximal and distal sections were compared. There was a significantly better overall canal fit obtained by THA with CT-based navigation system compared to without the navigation system (p<0.01). With CT-based navigation system, 42 of 50 stems (84%) were categorized as Type I fit compared to 31 of 50 stems (62%) without the navigation system. As to Type II fit, There are significantly more stems without the navigation system (26%) compared to with it (12%). There were better canal fills of the stems obtained by THA with CT-based navigation system both in proximal (94%) and distal sections (88%) of the femur compared to without the navigation system (proximal 88%/distal 82%) (p<0.05). Excellent radiographic fit and fill has been previously reported to potentially correlate with improved clinical outcomes. The stems obtained by THA with CT-based navigation system had a significantly better canal fit demonstrated by higher proportion of Type I and lower proportion of Type II fits, compared to without the navigation system. The stems with the navigation system had also significantly better proximal and distal canal fill.
The systemic use of steroids and habitual alcohol
intake are two major causative factors in the development of idiopathic
osteonecrosis of the femoral head (ONFH). To examine any interaction
between oral corticosteroid use and alcohol intake on the risk of
ONFH, we conducted a hospital-based case-control study of 71 cases
with ONFH (mean age 45 years (20 to 79)) and 227 matched controls
(mean age 47 years (18 to 79)). Alcohol intake was positively associated
with ONFH among all subjects: the adjusted odds ratio (OR) of subjects
with ≥ 3032 drink-years was 3.93 (95% confidence interval (CI) 1.18
to 13.1) compared with never-drinkers. When stratified by steroid use,
the OR of such drinkers was 11.1 (95% CI 1.30 to 95.5) among those
who had never used steroids, but 1.10 (95% CI 0.21 to 4.79) among
those who had. When we assessed any interaction based on a two-by-two
table of alcohol and steroid use, the OR of those non-drinkers who
did use steroids was markedly elevated (OR 31.5) compared with users
of neither. However, no further increase in OR was noted for the
effect of using both (OR 31.6). We detected neither a multiplicative
nor an additive interaction (p for multiplicative interaction 0.19;
synergy index 0.95), suggesting that the added effect of alcohol
may be trivial compared with the overwhelming effect of steroids
in the development of ONFH. Cite this article:
Intraoperative pulmonary fat and bone-marrow embolism is a serious complication of bone and joint surgery. We have investigated the occurrence and incidence of intraoperative embolism in patients undergoing elective lumbar spinal surgery with or without instrumentation. Sixty adult patients with lumbar degenerative disease were examined by intraoperative transoesophageal echocardiography while undergoing posterior lumbar surgery. Of these, 40 underwent surgery with instrumentation and 20 without. Moderate to severe (grade 2 or 3 according to the grading scale of Pitto et al) embolic events were seen in 80% of the instrumented patients but in none of the non-instrumented patients (p <
0.001). The insertion of pedicle screws was particularly associated with large numbers of pulmonary emboli, while the surgical approach, laminectomy, disc removal and bone harvesting were associated with small numbers of emboli. We consider that, as in arthroplasty and intramedullary fixation of fractures, these embolic events are relevant to the development of potentially fatal fat embolism during spinal surgery.
Spasm or contracture of gastrocnemius causes an equinus deformity of the ankle in both cerebral palsy and hemiplegia. Its release is therefore required in the treatment of those patients who do not respond to conservative measures. The Vulpius procedure is a simple and effective method for the release of gastrocnemius and is particularly indicated when long periods of immobilisation of the foot and ankle are not desirable. We have used this procedure with good results to correct an equinus deformity in 230 adults with a cerebrovascular accident and various associated medical conditions. It is not only effective in cerebral palsy, but should be considered at an early stage in all adult patients with deformity of the ankle and foot in whom spasm of gastrocnemius is the major cause.
We describe a new method of biological repair of osteochondral defects. In rabbit knees an osteochondral defect was reconstructed with a callo-osseous graft made of a superficial sheet of medullary fracture callus attached to a base of cancellous bone. This was taken from the iliac bone of the same animal which had been osteotomised ten days earlier. The reparative tissues were evaluated for 24 weeks by quantitative histology, biochemical analysis of the uronic acid content, and immunohistochemical staining of collagen constituents. The callo-osseous graft provided significantly faster and better repair of the articular surface than an untreated defect or a callo-osseous graft in which the cells had been devitalised by irradiation before transplantation. Our findings indicate that the callo-osseous graft contributes to the repair process by providing both favourable extracellular matrices and pluripotential mesenchymal cells. Our study tested the hypothesis that early medullary callus generates hyaline cartilage instead of bone after transfer to an articular surface.
We studied the effects of high-dose irradiation on the mechanical properties and morphology of cortical bone in rabbits for 52 weeks after a single dose of 50 Gy of electron-beam to the tibia. After four weeks, the bending strength of the irradiated bone was unchanged, but at 12 weeks, the strength had decreased significantly. At 24 weeks after irradiation mean strength was less than half of controls but by 52 weeks there was a tendency toward recovery. Similar, synchronous changes of damage and recovery were seen in cortical porosity, haematopoietic cells in the bone marrow and endosteal new bone formation.
