Influence of the type of stem and its fixation on revision and immediate postoperative mortality in elective total hip arthroplasty.

Aims: Despite higher rates of revision after total hip arthroplasty (THA) being reported for uncemented stems in patients aged > 75 years, they are frequently used in this age group. Increased mortality after cemented fixation is often used as a justification, but recent data do not confirm this association. The aim of this study was to investigate the influence of the design of the stem and the type of fixation on the rate of revision and immediate postoperative mortality, focusing on the age and sex of the patients. Methods: A total of 333,144 patients with primary osteoarthritis (OA) of the hip who underwent elective THA between November 2012 and September 2022, using uncemented acetabular components without reconstruction shells, from the German arthroplasty registry were included in the study. The revision rates three years postoperatively for four types of stem (uncemented, uncemented with collar, uncemented short, and cemented) were compared within four age groups: < 60 years (Young), between 61 and 70 years (Mid-I), between 71 and 80 years (Mid-II), and aged > 80 years (Old). A noninferiority analysis was performed on the most frequently used designs of stem. Results: The design of the stem was found to have no significant influence on the rate of revision for either sex in the Young group. Uncemented collared stems had a significantly lower rate of revision compared with the other types of stem for females in the Mid-I group. There was a significantly higher rate of revision for uncemented stems in females in the Mid-II group compared with all other types of stem, while in males the rate for uncemented stems was only significantly higher than the rate for cemented stems. Cemented stems had a significantly lower revision rate compared with uncemented and short stems for both sexes in the Old cohort, as did females with collared stems. The rate of immediate postoperative mortality was similar for all types of stem in the Old age group, as were the American Society of Anesthesiologists grades. Conclusion: In patients aged > 80 years, uncemented and short stems had significantly higher revision rates compared with cemented and collared stems, especially in females. The design of the stem and type of fixation have to be analyzed in more detail than only considering cemented and uncemented fixation, in order to further improve the success of THA.

Increased ankle pain after total knee arthroplasty is associated with a preoperative lateralized gait and talar tilt, but not with ankle laxity or the range of motion of the subtalar joint.

Aims: Total knee arthroplasty (TKA) may provoke ankle symptoms. The aim of this study was to validate the impact of the preoperative mechanical tibiofemoral angle (mTFA), the talar tilt (TT) on ankle symptoms after TKA, and assess changes in the range of motion (ROM) of the subtalar joint, foot posture, and ankle laxity. Methods: Patients who underwent TKA from September 2020 to September 2021 were prospectively included. Inclusion criteria were primary end-stage osteoarthritis (Kellgren-Lawrence stage IV) of the knee. Exclusion criteria were missed follow-up visit, post-traumatic pathologies of the foot, and neurological disorders. Radiological angles measured included the mTFA, hindfoot alignment view angle, and TT. The Foot Function Index (FFI) score was assessed. Gait analyses were conducted to measure mediolateral changes of the gait line and ankle laxity was tested using an ankle arthrometer. All parameters were acquired one week pre- and three months postoperatively. Results: A total of 69 patients (varus n = 45; valgus n = 24) underwent TKA and completed the postoperative follow-up visit. Of these, 16 patients (23.2%) reported the onset or progression of ankle symptoms. Varus patients with increased ankle symptoms after TKA had a significantly higher pre- and postoperative TT. Valgus patients with ankle symptoms after TKA showed a pathologically lateralized gait line which could not be corrected through TKA. Patients who reported increased ankle pain neither had a decreased ROM of the subtalar joint nor increased ankle laxity following TKA. The preoperative mTFA did not correlate with the postoperative FFI (r = 0.037; p = 0.759). Conclusion: Approximately one-quarter of the patients developed ankle pain after TKA. If patients complain about ankle symptoms after TKA, standing radiographs of the ankle and a gait analysis could help in detecting a malaligned TT or a pathological gait.

Effect of total hip arthroplasty on brake reaction time and braking force.

INTRODUCTION: The correct moment for return to driving after total hip arthroplasty (THA) remains unclear. Until today no uniform recommendation exists on the ability to perform an emergency brake.The aim of this prospective study was to investigate the braking ability of patients before and after THA implantation based on brake reaction time in milliseconds (BRT) and braking force in N (BF). METHODS: In total, 25 patients (15 men, 10 women, mean age 51.3 ± 10.1 years) were treated with THA on the right side. Inclusion criteria consisted of a valid driving licence, frequent road participation and at least 2 years of driving experience. Exclusion criteria were underlying neurological disorders as well as severe complaints in the lumbar spine and the right knee joint. The brake ability was evaluated for emergency braking with a car simulator and a measuring sole. Measurements were performed preoperatively, 6 days, 2, 4 and 6 weeks after surgery. RESULTS: Preoperatively, the mean BRT was 671.3 ± 123.5 ms and the BF 455.4 ± 185.0 N. Significant differences were observed at 6 days and 2 weeks after surgery, (BRT 836.4 ± 219.7 ms, respectively, BRT 735.0 ± 186.7 ms, and BF 302.6 ± 154.9 N, respectively, BF 375.5 ± 149.3 N, p < 0.05). Only 4 weeks after, no significant differences were seen compared to pre-operative with a BRT of 647.0 ± 91.9ms (p = 0.354) and BF of 435.9 ± 177.4 (p = 0.843). Furthermore, the BRT improved significantly after 6 weeks (607.4 ± 87.6; p = 0.005). CONCLUSIONS: The braking force is significantly reduced, and the brake reaction time is prolonged directly after surgery for at least 2 weeks. After 4 weeks, no statistically significant differences were measured, although special care should still be taken during return to activity.

Local infiltration anaesthesia versus sciatic nerve and adductor canal block for fast-track knee arthroplasty: A randomised controlled clinical trial.

BACKGROUND: Local infiltration anaesthesia (LIA) was introduced as an innovative analgesic procedure for enhanced recovery after primary total knee arthroplasty (TKA). However, LIA has never been compared with analgesia based on an adductor canal catheter and a single-shot sciatic nerve block. OBJECTIVE: To evaluate two analgesic regimens for TKA comparing mobility, postoperative pain and patient satisfaction. DESIGN: Two-group randomised, controlled clinical trial. SETTING: Charité-Universitätsmedizin Berlin, Campus Charité Mitte, Germany between April and August 2017. PATIENTS: Adults undergoing primary TKA under general anaesthesia were eligible for study participation. Exclusion criteria were heart insufficiency (New York Heart Association class >2), liver insufficiency (Child Pugh Score >B), evidence of diabetic polyneuropathy, severe obesity (BMI > 40 kg m), chronic opioid therapy for more than 3 months before scheduled surgery and allergy to local anaesthetics. INTERVENTIONS: Nerve block patients group (n=20) underwent surgery with two ultrasound-guided regional anaesthesia blocks: a single-shot sciatic nerve block with 20 ml of ropivacaine 0.75% combined with an adductor canal block with a catheter placed for less than 4 days with an infusion of ropivacaine 0.2% at a rate of 6 ml h. LIA patients (LIA group, n=20) received LIA of the knee capsule at the end of surgery with 150 ml of ropivacaine 0.2%. MAIN OUTCOME MEASURES: The primary endpoint was postoperative time to patient mobilisation (ability to walk) on the ward. RESULTS: Baseline characteristics were similar in each study group. Patients in both groups were mobilised to walk after TKA in similar time frames (LIA 24.0 h versus nerve block 27.1 h, 95% CI of difference -9.6 to 3.3 h). Maximum postoperative pain scores on exertion were higher in LIA patients with a mean 1.3 of 10 numerical rating scale points (95% CI 0.3 to 2.3, P = 0.010) as were intra-operative opioid requirements (LIA median 107 [IQR 100 to 268] mg versus nerve block median 78 [60 to 98] mg, P < 0.001). Patient satisfaction, postoperative oral morphine-equivalents and resting pain levels were comparable between groups. Anaesthesia induction time was reduced in LIA patients (LIA 10 min versus nerve block 35 min, 95% CI of difference 13 to 38 min, P < 0.001). CONCLUSION: Both analgesic regimens allow early mobilisation after TKA with high patient satisfaction. LIA shortened peri-operative time. Further research is required to optimise especially pain control during the later postoperative period with LIA. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT03114306.