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Multimodal Periarticular Injection Vs Continuous Femoral Nerve Block After Total Knee Arthroplasty: A Prospective, Crossover, Randomized Clinical Trial

This study compares the efficacy of pain control using continuous femoral nerve block (FNB) and multimodal periarticular soft tissue injection. This is a randomized, crossover, clinical trial. Sixteen patients having bilateral osteoarthritis of the knee scheduled for staged total knee arthroplasty were randomized to receive either FNB (0.2% ropivacaine), via indwelling catheter for 72 hours, or multimodal periarticular soft tissue injection in the first stage. In the second stage, they received the opposite treatment. The primary outcome measure was morphine consumption by patient-controlled analgesia in the first 72 hours postoperatively. Cumulative morphine consumption as well as rest pain and motion pain in the first 72 hours was comparable between the 2 groups. The functional outcomes did not differ significantly. We conclude that multimodal periarticular soft tissue injection provides comparable analgesia to continuous FNB after total knee arthroplasty.

Comparison of range of motion after standard and high-flexion posterior stabilised total knee replacement

The purpose of this study was to compare the range of motion after standard version posterior stabilised TKR and high-flexion version TKR in patients receiving bilateral total knee replacement. Thirty-five patients were recruited. The range of motion of the knees was measured clinically with a goniometer in both the pre-operative period and the most recent follow-up. It was found that the pre-operative range of motion was comparable in the two groups. The average post-operative flexion was 105° ± 13° in the standard version group and 106° ± 14° in the high-flexion design group (p = 0.201, paired t-test; beta error = 0.073). A slight loss in flexion was observed in the standard version group (0.5°) as opposed to a slight gain in the high-flexion design group (2°). However, this was not statistically significant (p = 0.251, paired t-test; beta error = 0.105).RésuméLe but de cette étude est de comparer la mobilité du genou après prothèse totale postéro stabilisée et prothèse total type « high-flexion », tous les patients étant opérés des deux genoux dans le même temps opératoire. 35 patients ont été inclus, la mobilité des genoux a été mesurée cliniquement en pré-opératoire et au plus grand recul. La mobilité pré-opératoire a été comparable dans les deux groupes, la mobilité post opératoire a été de 105° ± 13° dans la prothèse standard contre 106°  ± 14° dans les prothèses dites « high-flexion » (p = 0.201). Une petite perte de flexion est observée dans le groupe standard (0.5°), le gain dans le groupe des prothèses dites « high-flexion » est modéré (2°). Il n’y a pas de différences significatives entre ces deux groupes (p = 0.251).

Continuous Femoral Nerve Block versus Patient-Controlled Analgesia following Total Knee Arthroplasty:

Purpose. To compare total knee arthroplasty (TKA) patients who received continuous femoral nerve block (FNB) with local anaesthetics through a catheter versus patient-controlled analgesia (PCA) with intravenous morphine. Methods. 50 women and 10 men aged 51 to 84 years with matched characteristics underwent TKA and received either continuous FNB with local anaesthetics through a catheter (n=30) or PCA with intravenous morphine (n=30). None of the patients had had previous knee surgery. All operations were performed according to the standard protocol. Daily mean pain numerical rating scale at rest (NRS-R) and during movement (NRS-M), requirement of extra pain control, complications related to pain control, and overall patient satisfaction in both groups were compared. Results. Both groups were similar in terms of pain NRS-R and NRS-M, overall satisfaction, and length of hospital stay. Within each group, pain NRS-M score was significantly higher than pain NRS-R score. In the FNB group, 3 patients had dislodgement of the femoral catheter on day 1 and switched to PCA with intravenous morphine. Two of them had fair satisfaction. Patients in the PCA group had significantly more side-effects (nausea, vomiting, dizziness, and pruritis); 2 of the 5 patients with nausea and vomiting had fair satisfaction. No patients had any surgical complication. Conclusion. Both FNC and PCA provide reliable pain control.

Extensively coated femoral components in revision hip arthroplasty: follow-up study of 23 patients.

Purpose. To review the outcome of revision hip arthroplasty using extensively coated femoral components. Methods. We reviewed the results of revision involving 24 extensively porous-coated cementless femoral components in 23 patients, whose mean age was 52.4 years (range, 28.0–79.0 years). Most revisions were performed for aseptic loosening of the previously cemented femoral component. All patients were followed up for a minimum period of 24.0 months (mean, 61.1 months). Results. Of the 24 femoral stems, 20 showed bone ingrowth, 3 showed stable fibrous ingrowth, and one was unstable because of deep infection. Intra-operative anterior femoral diaphyseal perforation occurred in 2 hips during the insertion of straight femoral components of 200 mm. Postoperative radiographs displayed marked cortical erosion in 3 other hips and cortical perforation in one. Conclusion. The results from the use of extensively coated femoral components were promising. Nevertheless, anterior cortical perforations were also common, which may be related to more bowing of the femora among the Chinese patients. Caution must be exercised when inserting a long, straight, extensively coated femoral component.

Anterior dislocation after total hip replacement - effects of pelvic rotation and femoral head size.

We investigated the effects of pelvic rotation and femoral head diameter on the anterior stability of the hip joint after total hip replacement. Computer navigation and cadaveric bone were used to simulate the range of motion after total hip replacement. The hip was put at 0 degrees of flexion and it was gradually externally rotated until the hip dislocated. The degree of external rotation when the hip was dislocated was recorded. The test was repeated with the hip at +10, −10, −20, −30, −40 and −50 degrees of flexion. The acetabular component was positioned with abduction of 45 degrees and anteversion at 20 degrees. There was a significant difference amongst each group of pelvic rotation from 0 to −50 degrees in the degree of external rotation when the hip was dislocated. The degree became insignificant when pelvic rotation was increased from 0 to 10 degrees. From −10 to −50 degree of pelvic rotation, 36mm head had significant better stability compared with 32mm and 28mm femoral heads. The presence of significant pelvic sagittal malrotation can increase the risk of anterior dislocation. A larger femoral head is more stable than smaller heads. When pelvic sagittal malrotation is not present, there is no difference in stability between large and small femoral heads.