Vitamin E-infused highly cross-linked polyethylene (E1) has recently been introduced in total knee arthroplasty (TKA). An in vitro wear simulator study showed that E1 reduced polyethylene wear. However there is no published information regarding in vivo wear. Previous reports suggest that newly introduced materials which reduce in vitro polyethylene wear do not necessarily reduce in vivo polyethylene wear. To assist in the evaluation of the newly introduced material before widespread use, we established an in vivo polyethylene wear particle analysis for TKA. The aim of this study was to compare in vivo polyethylene wear particle generation between E1 and conventional polyethylene (ArCom) in TKA. A total of 34 knees undergoing TKA (17 each with ArCom or E1) were investigated. Except for the polyethylene insert material, the prostheses used for both groups were identical. Synovial fluid was obtained at a mean of 3.4 years (SD 1.3) postoperatively. The in vivo polyethylene wear particles were isolated from the synovial fluid using a previously validated method and examined by scanning electron microscopy.Aims
Methods
The aim of this study was to assess the effectiveness of perioperative essential amino acid (EAA) supplementation to prevent rectus femoris muscle atrophy and facilitate early recovery of function after total knee arthroplasty (TKA). The study involved 60 patients who underwent unilateral TKA for primary knee osteo-arthritis (OA). This was a double-blind, placebo-controlled, randomized control trial with patients randomly allocated to two groups, 30 patients each: the essential amino acid supplementation (9 g daily) and placebo (lactose powder, 9 g daily) groups. Supplementation and placebo were provided from one week before to two weeks after surgery. The area of the rectus femoris muscle were measured by ultrasound imaging one month before surgery and one, two, three, and four weeks postoperatively. The serum albumin level, a visual analogue knee pain score, and mobility were also measured at each time point. The time to recovery of activities of daily living (ADLs) was recorded. Postoperative nutrition and physiotherapy were identical in both groups.Aims
Methods
The use of vitamin E-infused highly crosslinked polyethylene (HXLPE) in total knee prostheses is controversial. In this paper we have compared the clinical and radiological results between conventional polyethylene and vitamin E-infused HXLPE inserts in total knee arthroplasty (TKA). The study included 200 knees (175 patients) that underwent TKA using the same total knee prostheses. In all, 100 knees (77 patients) had a vitamin E-infused HXLPE insert (study group) and 100 knees (98 patients) had a conventional polyethylene insert (control group). There were no significant differences in age, sex, diagnosis, preoperative knee range of movement (ROM), and preoperative Knee Society Score (KSS) between the two groups. Clinical and radiological results were evaluated at two years postoperatively.Aims
Patients and 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
Surgical-site-infections (SSI) prolong hospital stay, and they are leading nosocomial cause of morbidity and a source of excess cost. Recently, a waterless hand-rubbing protocol containing aqueous 1% chlorhexidine gluconate was developed before surgery, but there is no literature in orthopaedic surgery. The aim was to compare the SSI rates between waterless hand-rubbing and traditional hand-scrubbing protocol. STUDY 1: A total of 996 consecutive patients who underwent orthopaedic surgery between August 1, 2012 and January 31, 2014, were screened for SSI within 30 days after surgery. 500 patients from August 1, 2012 to April 1, 2013 were used by traditional hand-scrubbing, and 496 patients from June 1, 2013 to January 1, 2014 were by waterless hand-rubbing. STUDY 2: The twelve operating room staff members were randomly recruited, and the participants were assigned equally to use either a traditional hand-scrubbing protocol or a waterless hand-rubbing on 2 separate days. Washing times were recorded and microorganisms on hands were sampled on bacterial culture plates. Two days after sampling, the grown colonies were counted.[Introduction]
[Materials and Methods]
In 1970's, condylar type knee prosthese with anatomic design appeared, however, joint flexion was not satisfactory. Y/S II total knee arthroplasty (TKA) was developed to obtain deep flexion together with bilateral ligament balance in 1980. The articular surface of the tibial component was flattened to permit femoral shift posteriorily during knee flexion. Medial and lateral soft tissue release was determined by a unique ligament tensor both at flexion and extension. A metal tray was embedded in polyethylene, which had a shape of glasses frame. Though the usage of Y/SII TKA was finished in 1984, we here studied its long term surgical results using the Kaplan-Meyer method. From 1988 to 1991, 122 knees were replaced by Y/SII TKA in 81 patients with rheumatoid arthritis (RA). Among them, 24 joints in 12 patients were examined directly. The average age of follow-up was 19.5 years. The survival rate was investigated according to medical records.Back ground
Study design
Clinical outocome of revision total elbow arthroplasty(TEA) in rheumatoid arthritis(RA) patients were evaluated. Clinical outocome of revision TEA that underwent between 2005 and 2013 were evaluated. Causes of revision, implanted revised prosthesis, a clinical score (the Japanese Orthopaedic Association (JOA) elbow assessment score), the arc of motion and complications were investigated. Totally, 6 patients underwent revision TEA. The patients were females with a mean age of 60.4 years (range, 32 to 72).Purpose
Methods
Cup orientation of total hip arthroplasty (THA) is critical for dislocation, range of motion, polyethylene wear, pelvic osteolysis, and component migration. But, substantial error under manual technique has been reported specially in revision THA due to a bone loss and poor anatomical landmark. We have used three kinds of navigation systems for cup positioning in primary and revision THA. The purpose of this study is to evaluate the accuracy of navigation in revision THAs.INTRODUCTION
OBJECTIVES
Recently, as the number of total knee arthroplasty (TKA) is increasing, the number of revision TKA due to loosening or osteolysis is rapidly increasing. Large bone defect is one of the most critical issues during revision TKA. Therefore, early detection of bone loss around the TKA prosthesis before bone loss has been enlarged is very important. However, it is difficult to detect the loosening or ostolysis at the early stage around the femoral component even using fluoroscopically guided plain radiograph. A novel technique of tomography (Tomosynthesis; Shimazu Corporation, Kyoto, Japan) was introduced to detect the small bone loss. The purpose of this study was to examine, in a pig model of radiolucent line and osteolysis around TKA, the sensitivity and specificity of detection of radiolucent line and osteolysis using fluoroscopically guided plain radiographs and a novel technique of tomography. Six cemented femoral components (PFC Sigma; DePuy, Warsaw, IN, USA) were implanted in pig knees. Two components were implanted with standard cement technique (Standard model). Two components were implanted with 2 mm-thick defect between the cement and bone (Radiolucent line model). Two components were implanted with cystic defects (mean size = 0.7 cm3) in femoral condyles (Osteolysis model). The simulated bone lesions were filled with agarose to simulate granuloma tissue and to reduce the air artifact around the bone lesions, which can interfere with imaging techniques (Figure 1). Fluoroscopically guided plain radiographs (63 kV, 360 mA, 50 msec) were taken in 4 postures (antero-posterior, lateral, and +/−45 degrees oblique views) for each specimen (Figure 2). For Tomosynthesis, 74 frames were acquired in the rate 30 frames/sec with fixed X-ray condition (65 kV 1.25 mAs) and were reconstructed (Figure 3). Seven blinded assessors experienced in clinical radiographic analysis examined. The sensitivities, specificities and accuracy of the two imaging techniques were compared.INTRODUCTION
METHODS
Over the past decade, there has been an increase in the number of total knee arthropalsty (TKA). Demand of TKA for the young patients who often have high physical demands is also increasing. However, the revision rate in such young patients is much higher due to polyethylene (PE) wear and instability (Julin J, Acta Orthop 2010). Therefore, next generation total knee prostheses are expected to decrease PE wear and to provide stability. Although Patients who underwent bilateral staged TKAs were more likely to prefer medial pivot prosthesis or ACL-PCL retaining prosthesis than the other types of prostheses, because they feels “more stable overall” (Pritchett JW, J Arthroplasty 2011). The excellent mid-term clinical results of those newly introduced total knee prosthesis, such as alumina medial pivot TKA (Iida T, ORS 2008), medial pivot TKA (Mannan K, JBJS Br 2009, Kakachalions T, Knee 2009), ACL-PCL retaining TKA (Clouter JM, JBJS Am 1999), and highly cross-linked PE (Hodrick JT, CORR 2008), have been reported. From the point of view of
Total ankle arthrpoplasty (TAA) was performed frequently for ankle deformity caused by rheumatoid arthritis (RA) and osteoarthritis (OA). TAA has some advantages over ankle arthrodesis in range of motion (ROM). However, loosening and sinking of implant have been reported with several prostheses, especially constrained designs. Recently, we have performed mobile bearing TAA and report short term results of this prosthesis followed average 3 years. 20 total ankle prostheses were implanted in patients with RA (n=14) or OA (n=6) in 19 patients (5 male and 14 female, one bilateral), between 2005 and 2009. We used FINE total ankle arthroplasty that is mobile bearing system (Nakashima Medical Co., Ltd, Okayama, Japan). All patients were assessed for American Orthopaedic Foot and Ankle Society (AOFAS) score, ROM in plantar flexion and dorsiflexion at the point of pre-operation and final follow-up. We evaluated radiolucent line, sinking, and alignment of prostheses at final follow-up.Background
Method
There is many reports about complications with a resurfacing total hip arthroplasty (RHA). One of the most common complications is the femoral neck fracture. A notch and malalignment were risk factors for this. For an accurate implanting the femoral component in RHA, we performed 3D template and made a patient specific template (PST) using 3D printer and applied this technique for a clinical usage. We report a preliminary early result using this novel technique. We performed 10 RHAs in nine patients (7 male, 2 female) from June 2009 to March 2010 due to osteonecrosis in 7 hips and secondary osteoarthritis in 3hips with a mean age of 48 years (40-60). We obtained a volumetric data from pre-operative CT and planned using 3D CAD software. Firstly, size of femoral components were decided from the size planning of cups. We aimed a femoral component angle as ten degrees valgus to the neck axis in AP and parallel in lateral view avoiding a notch. We measured femoral shaft axis and femoral neck axis in AP and lateral view using 3D processing software. PSTs were made using Laser Sintering by 3D printer which had the heat tolerance for sterilization in order to insert the femoral guide wire correctly. We operated in postero-lateral approach for all the patients PST has the base (contact part) fit to poterior inter trochanteric area. It has the arm reached from the base and sleeve hole to insert the guide pin into the femoral head. We measured the femoral component angle in three dimensions using the 3D processing software postoperatively. We compared the difference of this angle and the pre-operative planed angles. We also investigated the operation time, the volume of bleeding during operation and complications.Introduction
material and method
Bone mineral density (BMD) around the femoral component has been reported to decrease after total knee replacement (TKR) because of stress shielding. Our aim was to determine whether a cemented mobile-bearing component reduced the post-operative loss of BMD. In our study 28 knees receiving a cemented fixed-bearing TKR were matched with 28 receiving a cemented mobile-bearing TKR. They underwent dual-energy x-ray absorptiometry, pre-operatively and at three weeks and at three, six, 12, 18 and 24 months post-operatively. The patients were not taking medication to improve the BMD. The pre-operative differences in the BMD of the femoral neck, wrist, lumbar spine and knee in the two groups were not significant. The BMD of the femur decreased postoperatively in the fixed-bearing group, but not the mobile-bearing group. The difference in the post-operative change in the BMD in the two groups was statistically significant (p <
0.05) at 18 and 24 months. Our findings show that a cemented mobile-bearing TKR has a favourable effect on the BMD of the distal femur after TKR in the short term. Further study is required to determine the long-term effects.
We studied 21 patients with a spontaneous palsy of the anterior interosseous nerve. There were 11 men and 10 women with a mean age at onset of 39 years (17 to 65). Pain around the elbow or another region (forearm, shoulder, upper arm, systemic arthralgia) was present in 17 patients and typically lasted for two to three weeks. It had settled within six weeks in every case. In ten cases the palsy developed as the pain settled. A complete palsy of flexor pollicis longus and flexor digitorum profundus to the index finger was seen in 13 cases and an isolated palsy of flexor pollicis longus in five. All patients were treated without operation. The mean time to initial muscle contraction was nine months (2 to 18) in palsy of the flexor digitorum profundus to the index finger, and ten months (1 to 24) for a complete palsy of flexor pollicis longus. An improvement in muscle strength to British Medical Research Council grade 4 or better was seen in all 15 patients with a complete palsy of the flexor digitorum profundus and in 16 of 18 with a complete palsy of flexor pollicis longus. There was no significant correlation between the duration of pain and either the time to initial muscle contraction or final muscle strength. Prolonged pain was not always associated with a poor outcome but the age of the patient when the palsy developed was strongly correlated. Recovery occurred within 12 months in patients under the age of 40 years who achieved a final British Medical Research Council grade of 4 or better. Surgical decompression does not appear to be indicated for young patients with this condition.
We compared the biological characteristics of extrinsic fibroblasts infiltrating the patellar tendon with those of normal, intrinsic fibroblasts in the normal tendon Proliferation and invasive migration into the patellar tendon was significantly slower for infiltrative fibroblasts than for normal tendon fibroblasts. Flow-cytometric analysis indicated that expression of α5β1 integrin at the cell surface was significantly lower in infiltrative fibroblasts than in normal tendon fibroblasts. The findings suggest that cellular proliferation and invasive migration of fibroblasts into the patellar tendon after necrosis are inferior to those of the normal fibroblasts. The inferior intrinsic properties of infiltrative fibroblasts may contribute to a slow remodelling process in the grafted tendon after ligament reconstruction.
Posterior approach to the lumbar spine necessarily induces structural damage of paravertebral muscles. In order to avoid these changes, we have started to utilize a microscopic decompression of the spinal canal via an unilateral approach since 1998. The purpose of this study was to evaluate the results of this operative procedure for lumbar spinal canal stenosis. A total of 18 patients, 13 men and five women, were reviewed. The age at the time of surgery ranged from 53years to 78years with a mean of 69.0years. Follow up period averaged 12.3months ranging from one to 32months. As for operative procedure, unilateral paravertebral muscle was retracted laterally and lam-inotomy in the approached side was performed. Following complete decompression of a nerve root in the approached side, microscope was tilted and the inner aspect of lamina in the contralateral side was resected using high-speed drill with a guard of yellow ligament to dural sac and nerve root. Following the procedure, yellow ligament was resected and nerve root in the contralateral side was decompressed. Results: In operation time, blood loss and recovery rate of JOA score, there were no statistical differences compared with ordinal laminotomy cases. Dural sac was well decompressed not only in the hemilaminec-tomy side but also in the contralateral side. All cases showed intensity change of paravertebral muscle in the approached side on T2 weighted MRI. Conclusion: The procedure described here was definitely effective because paravertebral muscle in the contralateral side and midline structure of the lumbar spine could be completely preserved.
We recorded compound muscle action potentials (CMAPs) from the diaphragm in 15 normal volunteers, nine patients with lesions of the lower cervical cord (C5 to C8), one completely quadriplegic patient (C6) and seven patients with lesions at a higher cervical level (C1 to C4). Transcranial magnetic stimulation and electrical stimulation of the phrenic nerve were carried out. When the centre of the coil was placed on the interauricular line at a point 3 cm lateral to the vertex on the scalp, the CMAPs from the diaphragm had the largest amplitude and the shortest latency. There was no difference in the mean latency of the CMAPs recorded by transcranial magnetic stimulation in the normal volunteers and in the patients with lesions of the lower cervical cord. In the quadriplegic patient, the latency of the CMAPs was not delayed, but was prolonged in the patients with lesions at a higher level. Those evoked by electrical stimulation of the phrenic nerve were not prolonged in the patients with higher lesions. Our findings suggest that the prolongation of the latency by transcranial magnetic stimulation reflects dysfunction of the higher cervical cord. The combination of transcranial magnetic stimulation and electrical stimulation of the phrenic nerve can detect the precise level of the lesion in the motor tract to the diaphragm.
In order to determine whether an allogeneic tendon could be used to replace an extra-articular ligament, the right medial collateral ligament from 11 adult dogs was replaced with a fresh-frozen allogeneic patellar tendon. At each of 3, 6, 15, 30 and 52 weeks postoperatively, one dog was killed for micro-angiographical and histological studies; at 52 weeks the remaining six dogs were killed for tensile testing. Micro-angiograms showed that the allogeneic tendon was revascularised with infiltration of the mesenchymal cells from the surrounding tissues and both ends of the graft. Histologically, the alignment of the fibroblasts and collagen bundles became more regular over time, without any immunological rejection. A biomechanical study performed at 52 weeks found no significant difference in stiffness or ultimate load between normal and reconstructed ligaments. Fresh-frozen allogeneic tendons are therefore considered useful for extra-articular ligament reconstruction.
We have developed an apparatus to measure the anteroposterior stability of the knee to forces of up to 250 N, applied at 20 degrees of flexion. We measured anterior laxity at 200 N, anterior stiffness at 50 N and total laxity at +/- 200 N. A study of cadaveric knees revealed that the soft tissues surrounding the bones had a significant influence on the force-displacement curve, and emphasised that differences between injured and normal pairs of knees are much more important than the absolute values of the parameters. In 61 normal volunteers we found no significant left to right differences in anterior laxity at 200 N and anterior stiffness at 50 N. In 92 patients with unilateral anterior cruciate deficiency there were significant differences (p less than 0.0005) in anterior laxity, anterior stiffness and total laxity, the injured-normal differences averaging 6.7 mm, 1.3 N/mm, and 8.1 mm respectively.
