Total intravenous general anaesthesia vs. spinal anaesthesia for total hip arthroplasty: a randomised, controlled trial.

BACKGROUND: The choice of anaesthetic technique for patients undergoing joint arthroplasty is debatable. The hypothesis of this study was that general anaesthesia would generate a more favourable recovery profile than spinal anaesthesia. METHODS: We randomly allocated 120 patients to either intrathecal bupivacaine or general anaesthesia with target-controlled infusion of remifentanil and propofol. Length of hospital stay assessed as meeting discharge criteria was the primary outcome parameter. Other outcome parameters were actual time of discharge, pain, use of rescue pain medication, blood loss, length of stay in the post-operative care unit, dizziness, post-operative nausea, need of urinary catheterisation and patient satisfaction. RESULTS: General anaesthesia resulted in slightly reduced length of hospital stay (26 vs. 30 h, P = 0.004), less nausea (P = 0.043) and dizziness (P < 0.001). General anaesthesia patients had higher pain scores during the first two post-operative hours (P < 0.001) but lower after 6 h compared with the spinal anaesthesia group (P < 0.01 and P < 0.05). General anaesthesia patients had better orthostatic function compared with spinal anaesthesia patients (P = 0.008). Patients in the spinal anaesthesia group fulfilled the discharge criteria from the post-operative care unit earlier compared with the general anaesthesia patients (P = 0.004). General anaesthesia patients requested a change in the method of anaesthesia for a subsequent operation less often than the spinal anaesthesia patients (5 vs. 13, P = 0.022). CONCLUSION: General anaesthesia resulted in a more favourable recovery profile compared with spinal anaesthesia.

Recovery after total intravenous general anaesthesia or spinal anaesthesia for total knee arthroplasty: a randomized trial.

BACKGROUND: This study was undertaken to compare the effects of general anaesthesia (GA) and spinal anaesthesia (SA) on the need for postoperative hospitalization and early postoperative comfort in patients undergoing fast-track total knee arthroplasty (TKA). METHODS: One hundred and twenty subjects were randomly allocated to receive either intrathecal bupivacaine (SA group) or GA with target controlled infusion of propofol and remifentanil (GA group). Primary outcome was length of hospital stay (LOS) defined as time from end of surgery until the subject met the hospital discharge criteria. Secondary outcome parameters included actual time of discharge, postoperative pain, intraoperative blood loss, length of stay in the Post Anaesthesia Care Unit, dizziness, postoperative nausea and vomiting, need for urinary catheterization and subject satisfaction. RESULTS: GA resulted in shorter LOS (46 vs 52 h, P<0.001), and less nausea and vomiting (4 vs 15, P<0.05) and dizziness (VAS 0 mm vs 20 mm, P<0.05) compared with SA. During the first 2 postoperative hours, GA patients had higher pain scores (P<0.001), but after 6 h the SA group had significantly higher pain scores (P<0.001). Subjects in the GA group used fewer patient-controlled analgesia doses and less morphine (P<0.01), and were able to walk earlier compared with the SA group (P<0.001). Subjects receiving SA would request a change in the method of anaesthesia in the event of a subsequent operation more often than the GA subjects (P<0.05). CONCLUSION: GA had more favourable recovery effects after TKA compared with SA.

A 5 year prospective study of patient-relevant outcomes after total knee replacement.

OBJECTIVE: To prospectively describe self-reported outcomes up to 5 years after total knee replacement (TKR) in Osteoarthritis (OA) and to study which patient-relevant factors may predict outcomes for pain and physical function (PF). METHODS: 102 consecutive patients with knee OA, 63 women and 39 men, mean age 71 (51-86) assigned for TKR at the Department of Orthopaedics at Lund University Hospital were included in the study. The self-administered questionnaires Knee injury and Osteoarthritis Outcome Score (KOOS) and SF-36 were mailed preoperatively and 6 months, 12 months and at 5 years postoperatively. RESULTS: Response rate at 5 years was 86%. At 6 months significant improvement was seen in all KOOS and SF-36 scores (P<0.001). The percentage of patients performing more demanding functions related to sports and recreation increased postoperatively. The best postoperative result was reported at the 1 year follow-up. Compared to the 1 year follow-up, a significant (P

Fixation and clinical outcome of uncemented peri-apatite-coated versus cemented total knee arthroplasty : five-year follow-up of a randomised controlled trial using radiostereometric analysis (RSA).

AIMS: The optimal method of tibial component fixation remains uncertain in total knee arthroplasty (TKA). Hydroxyapatite coatings have been applied to improve bone ingrowth in uncemented designs, but may only coat the directly accessible surface. As peri-apatite (PA) is solution deposited, this may increase the coverage of the implant surface and thereby fixation. We assessed the tibial component fixation of uncemented PA-coated TKAs versus cemented TKAs. PATIENTS AND METHODS: Patients were randomised to PA-coated or cemented TKAs. In 60 patients (30 in each group), radiostereometric analysis of tibial component migration was evaluated as the primary outcome at baseline, three months post-operatively and at one, two and five years. A linear mixed-effects model was used to analyse the repeated measurements. RESULTS: After five years of follow-up, one (cemented) component was revised due to ligament instability. Overall, uncemented PA-coated tibial components migrated significantly more (p = 0.003), with the mean maximum total point motion (MTPM) at five years being 0.62 mm (95% confidence intervals (CI) 0.49 to 0.76) for cemented tibial components and 0.97 mm (95% CI 0.81 to 1.15) for PA-coated tibial components in TKA. However, between three months and five years the cemented TKAs migrated significantly more (p = 0.02), displaying a MTPM of 0.27 mm (95% CI, 0.19 to 0.36) versus 0.13 mm (95% CI, 0.01 to 0.25) for PA-coated tibial components. One implant in each group was considered at risk for aseptic loosening due to continuous migration after five years of follow-up, albeit with different migration patterns for each group (i.e. higher initial migration but diminishing over time for the PA-coated component versus gradually increasing migration for the cemented component). CONCLUSION: The tibial components of PA-coated TKAs showed more overall migration compared with the tibial components of cemented TKAs. However, post hoc analysis showed that this difference was caused by higher migration of PA-coated components in the first three months, after which a stable migration pattern was observed. Clinically, there was no significant difference in outcome between the groups. Cite this article: Bone Joint J 2017;99-B:1467-76.

Use of a biocompatible fiducial marker in evaluating the accuracy of computed tomography image registration.

RATIONALE AND OBJECTIVES: Accurate registration of computed tomography (CT) images to the patient is crucial for computer-assisted surgery. Markers used in roentgen stereo-grammetric analysis (RSA) can be located in a CT scan using a novel approach and also can be located physically. Roentgen stereo-grammetric analysis data act as "ground truth" for the three-dimensional marker locations. METHODS: Two foam-bone phantoms were marked. The markers were scanned seven times with RSA, three times with axial CT, and contacted four times with a coordinate measuring arm. Root-mean-square (RMS) errors were derived for the registrations. RESULTS: Computed tomography and RSA data register to 0.15 mm RMS error. Computed tomography and arm data register to 0.25 mm. The markers are biocompatible, and the coordinate measuring arm is usable in an operating room. CONCLUSIONS: Typical in vitro registration errors are approximately 2 mm. The authors have developed a marker that provides superior registration, and a procedure that can be used for in vivo studies.

Analysis of the distribution and frequency of trisomy 7 in vivo in synovia from patients with osteoarthritis and pigmented villonodular synovitis.

Osteoarthritis (OA) and pigmented villonodular synovitis (PVNS) are disorders associated with trisomy 7. The aim of the present study was to determine the frequency and distribution of the cells with +7 in vivo by analyzing sections of paraffin-embedded synovia from patients affected by OA, PVNS, other forms of synovitis [hemorragic synovitis (HS) and chronic synovitis (CS)], and from individuals without joint disease. Fluorescence in situ hybridization (FISH), using a centromeric probe for chromosome 7, showed that the mean frequency of trisomic nuclei in 5-microm sections was highest in PVNS (9.0%), followed by CS (5.9%), OA (5.6%), and HS (4.6%), whereas trisomic nuclei were rare (0.7%) in normal tissue. When 8-microm sections were studied, the frequencies of trisomic cells in OA and control synovia increased to 6.7% and 1.5%, respectively. Trisomic nuclei were found in all cases, including those for which cytogenetic analysis of short-term cultures had not disclosed any trisomic cells. Overall, the trisomic cells were scattered within the tissue. However, small clusters of cells with +7 were found in three cases. By hematoxylin-eosin staining of the slides used for FISH analysis it could be shown that the clustered trisomic cells were proliferating synoviocytes within villous extensions of the synovial membrane.

Early postoperative fixation of tibial components: an in vivo roentgen stereophotogrammetric analysis.

The fixation of cemented and noncemented tibial components in 19 total knee arthroplasties was examined 3 to 10 weeks postoperatively with roentgen stereophotogrammetric analysis. Physiologic external forces were applied either in outward-inward rotation or as eccentric posterior loading generated by squatting. In one case there was no motion, while in the remaining 18 cases relative interface motion of up to 1.3 mm was found. In some cases, the largest motion was found during inward-outward rotatory stress, while in others, the largest motion was found during squatting. Posterior tilt was weakly correlated with posterior displacement of the femoral component on the tibia during squatting (r2 = 0.323, p < 0.05). For the noncemented cases, the initial fixation to bone was probably insufficient, and ingrowth of bone would not have been achieved. For the cemented cases, motion of the implant was reduced. Given the short postoperative time and the probable absence of any substantial fibrous tissue membrane, we suggest that the observed motion represented elastic deformation of the bone.

Failure of partial cementation to achieve implant stability and bone ingrowth: a long-term roentgen stereophotogrammetric study of tibial components.

Thirty patients with gonarthrosis were operated on with the PCA primary total knee prosthesis and had the tibial component fixed to the bone by partial cementation. In the first two groups of patients, cementation was by a peripheral rim of high and low-viscosity cement, respectively. In the third group, the pegs were cemented with the low-viscosity cement. Follow-up was performed with use of clinical parameters and roentgen stereophotogrammetric analysis. Clinically, the series was successful apart from a problem with tibial component wear, necessitating revision in five patients. At 8 years, the mean Hospital for Special Surgery score was 81 points. Venn-diagram scores revealed four failures and three acceptable cases; the remaining cases were satisfactory. Apart from one loose patellar component, there was no mechanical loosening. Roentgen stereophotogrammetric analysis showed that the tibial components moved relative to the bone; this indicated fibrous tissue fixation, which was corroborated histologically in two patients. The objective, to achieve bone ingrowth, was thus not successfully met. Radiolucent lines were consistently seen, and their size correlated with the migration as measured by roentgen stereophotogrammetric analysis. Furthermore, five continuously migrating prostheses showed significantly larger radiolucent zones than the prostheses that migrated only initially, and they were less well bonded to the bone at 1 year. In conclusion, partial cementation does not appear to be a way to achieve bone ingrowth in porous-coated implants under load.

Early inducible displacement of tibial components in total knee prostheses inserted with and without cement: a randomized study with roentgen stereophotogrammetric analysis.

The fixation of tibial components randomized to insertion with or without cement in twenty-six knees was examined for inducible displacement at six weeks and one year postoperatively with use of roentgen stereophotogrammetric analysis. Furthermore, migration was studied during the first two postoperative years. Inducible displacement was found in all knees at both the six-week and the one-year follow-up examination, but no differences were detected with respect to the type of fixation (p > 0.05). All tibial components migrated for as long as one year postoperatively, after which most stabilized. No difference was found between the groups with respect to migration during the first two years postoperatively (p > 0.05), with the exception of subsidence of the component, which was found to be 0.0+/-0.1 millimeter (mean and standard error of the mean) for the components inserted with cement and 0.5+/-0.1 millimeter for the components inserted without cement (p < 0.01). Migration after one year was the same for both groups. We found a relationship between inducible displacement at six weeks and at one year as well as one between inducible displacement and migration at one year. To our knowledge, the present study is the first in which the micromotion of an interference-fit prosthesis was found to be similar to that of a device inserted with cement. The results of the present study emphasize the importance of the initial prosthetic fixation.

A comparison of hydroxyapatite-coated, titanium-coated, and uncoated tapered external-fixation pins. An in vivo study in sheep.

Three types of surfaces for external fixation pins were compared. One hundred and eight stainless-steel tapered 5/6-millimeter pins were divided into three groups: thirty-six pins remained uncoated (Group A), thirty-six were plasma-sprayed with hydroxyapatite (Group B), and thirty-six were plasma-sprayed with titanium (Group C). The pins were implanted in the left tibia of eighteen sheep, with each sheep receiving six pins from the same group. A unilateral fixator then was assembled on the pins. The medial aspect of the mid-part of the tibial diaphysis was exposed, and a five-millimeter-long cylinder of bone was removed so that load would be borne by the bone-pin interfaces. Six weeks after the procedure, radiographs demonstrated rarefaction of twenty-nine pin tracks in Group A, fifteen in Group B, and thirty in Group C (p = 0.021 for Group A compared with Group B and p = 0.016 for Group B compared with Group C). The mean final insertion torque (and standard deviation) was 4360+/-1050 newton-millimeters in Group A, 3420+/-676 newton-millimeters in Group B, and 3740+/-643 newton-millimeters in Group C. With the numbers available, no significant differences could be detected among these values. The mean extraction torque was 253+/-175 newton-millimeters in Group A, 3360+/-1260 newton-millimeters in Group B, and 1720+/-1030 newton-millimeters in Group C (p = 0.002 for Group A compared with Group B, p = 0.017 for Group A compared with Group C, and p = 0.03 for Group B compared with Group C). The extraction torque was significantly lower than the corresponding insertion torque in both Group A (p < 0.001) and Group C (p = 0.003); no significant difference could be found, with the numbers available, in Group B (hydroxyapatite-coated pins). At sixty times magnification, direct contact was seen along a mean of 16+/-9 per cent of the bone-pin interface in Group A, 30+/-12 per cent of the interface in Group B, and 28+/-15 per cent of the interface in Group C (p = 0.042 for Group A compared with Group C). However, at 10,000 times magnification, direct bone-pin contact was found only in Group B.

Digital automated RSA compared to manually operated RSA.

The accuracy of digital Roentgen stereophotogrammetric analysis (RSA) was compared to the accuracy of a manually operated RSA system. For this purpose, we used radiographs of a phantom and radiographs of patients. The radiographs of the patients consisted of double examinations of 12 patients that had a tibial osteotomy and of double examinations of 12 patients that received a total hip prosthesis. First, the radiographs were measured manually with an accurate measurement table. Subsequently, the images were digitized by a film scanner at 150 DPI and 300 DPI resolutions and analyzed with the RSA-CMS software. In the phantom experiment, the manually operated system produced significantly better results than the digital system, although the maximum difference between the median values of the manually operated system and the digital system was as low as 0.013mm for translations and 0.033 degrees for rotations. In the radiographs of the patients, the manually operated system and the digital system produced equally accurate results: no significant differences in translations and rotations were found. We conclude that digital RSA is an accurate, fast, and user friendly alternative for manually operated RSA. Currently, digital RSA systems are being used in a growing number of clinical RSA-studies.

Roentgen stereophotogrammetric analysis using computer-based image-analysis.

The two-dimensional position of markers in radiographs for Roentgen Stereophotogrammetric Analysis (RSA) is usually determined using a measuring table. The purpose of this study was to evaluate the reproducibility and the accuracy of a new RSA system using digitized radiographs and image-processing algorithms to determine the marker position in the radiographs. Four double-RSA examinations of a phantom and 18 RSA examinations from six patients included in different RSA-studies of knee prostheses were used to test the reproducibility and the accuracy of the system. The radiographs were scanned at 600 dpi resolution and 256 gray levels. The center of each of the tantalum-markers in the radiographs was calculated by the computer program from the contour of the marker with the use of an edge-detection software algorithm after the marker was identified on a PC monitor. The study showed that computer-based image analysis can be used in RSA-examinations. The advantages of using image-processing software in RSA are that the marker positions are determined in an objective manner, and that there is no need for a systematic manual identification of all the markers on the radiograph before the actual measurement.

Validation of a functional method for the estimation of hip joint centre location.

The present study assesses the accuracy with which the subject specific coordinates of the hip joint centre (HJC) in a pelvic anatomical frame can be estimated using different methods. The functional method was applied by calculating the centre of the best sphere described by the trajectory of markers placed on the thigh during several trials of hip rotations. Different prediction methods, proposed in the literature and in the present investigation, which estimate the HJC of adult subjects using regression equations and anthropometric measurements, were also assessed. The accuracy of each of the above-mentioned methods was investigated by comparing their predictions with measurements obtained on a sample of 11 male adult able-bodied volunteers using roentgen stereophotogrammetric analysis (RSA), assumed to provide the true HJC locations. Prediction methods estimated the HJC location at an average rms distance of 25-30 mm. The functional method performed significantly better and estimated HJCs within a rms distance of 13 mm on average. This result may be confidently generalised if the photogrammetric experiment is carefully conducted and an optimal analytical approach used. The method is therefore suggested for use in motion analysis when the subject's hip range of motion is not limited. In addition, the facts that it is not an invasive technique and that it has relatively small and un-biased errors, make it suitable for regression equations identification with no limit to sample size and population typology.

On the problem of heat generation in bone cutting. Studies on the effects on liquid cooling.

A saw blade was made from two standard oscillating blades which were fixed to each other with channels between, so that cooling fluid could be directed to the saw teeth. The blade was connected to a standard arthroscopy pump which delivered a flow of 80 ml/min through the blade. The performance of this blade was compared with that of a standard saw blade, cutting ox-bone in the laboratory. Irrigation of the standard saw blade with saline delivered by a syringe only slightly diminished the maximum temperature. Pumped irrigation was more effective but required large volumes of fluid. The heat generated by the internally cooled saw blade was negligible and the temperatures achieved (19 degrees C to 34 degrees C) fell well below the critical level for bone death (44 degrees C to 47 degrees C).

Hydroxyapatite coating of threaded pins enhances fixation.

We measured the insertion and extraction torque forces in a randomised study of 76 external fixation screws in 19 patients treated by hemicallotasis for osteoarthritis of the medial side of the knee. The patients were randomised to have either standard tapered screws (Orthofix 6/5 mm) or the same screws with hydroxyapatite (HA) coating. One patient had two standard and two HA-coated screws. All patients had an anterior external fixator (Orthofix T-garche), with two screws in the proximal tibial metaphysis parallel to and about 2 cm below the joint surface and two in the tibial diaphysis. The mean torque forces for insertion of the standard screws were 260 Ncm for the proximal to medial screw, 208 for the proximal to lateral screw and 498 and 546 Ncm for the diaphyseal pins. The corresponding forces for the HA-coated pins were not significantly different. The torque forces for the extraction of the standard pins were 2 Ncm for the proximal pins, 277 and 249 Ncm for the distal pins and 482, 478, 585 and 620 Ncm, respectively (p < 0.005) for the HA-coated pins. All 18 of the metaphyseal standard screws were loose at extraction (extraction force < 20 Ncm), but only one of the HA screws in the metaphysis was loose. In the diaphysis the standard screws lost about 40% of their fixation in contrast to the HA-coated screws which retained full fixation strength.

Hemicallotasis open-wedge osteotomy for osteoarthritis of the knee. Complications in 308 operations.

We studied the complications after open-wedge osteotomy by hemicallotasis in 308 consecutive patients, most of whom had osteoarthritis of the knee. The participating surgeons, who worked at 17 hospitals, used their discretion in selecting patients, operating techniques and external fixators. The general complications included 11 cases of deep-vein thrombosis (4%), six of nonunion (2%) and one of septic arthritis of the knee. There were technical complications in 13 patients (4%). In 157 patients (51%) pin-site infections were recorded; of these, 96% were minor and responded to wound toilet and antibiotic treatment. A total of 18 revision procedures was carried out.

Early migration of femoral components revised with impacted cancellous allografts and cement. A preliminary report of five patients.

We report the preliminary findings of the use of roentgen stereophotogrammetric analysis to evaluate the early migration of five femoral components after revision for mechanical loosening using impacted cancellous allograft and cement. All hips were examined at one week, four to six months and one year after surgery. All the components subsided by 0.4 to 4.9 mm during the first year. In four hips the prosthetic head was displaced 1.1 to 6.9 mm posteriorly. Fixation of the femoral components was less secure than after primary arthroplasty but the incidence and magnitude of early migration were similar to those after revision with cement alone.

Fixation of the tibial component of total knee arthroplasty after high tibial osteotomy: a matched radiostereometric study.

To assess migration of the tibial component we used roentgen stereophotogrammetric analysis in 40 patients who had had a total knee arthroplasty after failure of a closing wedge osteotomy and compared them with 40 matched patients after primary total knee arthroplasty. We found no difference in migration over time or in the tendency for continuous migration between the two groups. There were no differences in alignment or position of the knee prosthesis or in the clinical outcome. Our findings show that revision of a failed high tibial osteotomy to a total knee arthroplasty is effective.

Open-wedge osteotomy by hemicallotasis or the closed-wedge technique for osteoarthritis of the knee. A randomised study of 50 operations.

We describe the results of 50 operations carried out on 46 patients with medial osteoarthritis of the knee of Ahlbäck grade 1 to 3. Patients were randomised either to a closed-wedge high tibial osteotomy (HTO) or an open-wedge procedure based on the hemicallotasis technique (HCO). Their median age was 55 years (38 to 68). The preoperative median hip-knee-ankle (HKA) angle was 171 degrees (164 to 176) in the HTO group and 173 degrees (165 to 179) in the HCO group. After six weeks, the median HKA angle was 185 degrees (176 to 194) in the HTO group and 184 degrees (181 to 188) in the HCO group. In the HTO group, seven patients were within the range of 182 degrees to 186 degrees compared with 21 in the HCO group (p < 0.001). One year later, ten HTO patients were within this range while the HKA angulation in the HCO group was unchanged. At two years the numbers were 11 and 18, respectively. We evaluated the clinical results on the Hospital for Special Surgery, Lysholm and Wallgren-Tegner activity scores, and patients completed part of the Nottingham Health Profile questionnaire. An impartial observer at the two-year follow-up concluded that all scores had improved, but found no clinical differences between the groups.