Rate of complications and short-term Functional Results of Revision Total Knee Arthroplasty for Tibio-femoral Instability: do stability and range of motion are restored in 62 revisions.

Tibio-femoral instability (TFI) due to ligament imbalance is a growing cause of revision total knee arthroplasty (TKA). The results are heterogeneous in the event of revision and literature is scarce regarding this issue particularly when use of hinge prostheses is not exclusive to manage this complication. Therefore, a retrospective investigation was conducted aiming to (1) analyze the one-year functional results, (2) determine the rate of complications after revision for TFI using posterior-stabilized or condylar constrained knees (CCK), 3) identify the factors that could influence the function outcome. Patients undergoing revision TKA for TFI would show an improvement in Oxford Knee Score at one year postoperative. Sixty-two patients were included (40 females, 22 males) mean age 62,9 years ± 8.2 (range, 45,7-78,4). Instability was classified as instability in extension (n = 28), midflexion (n = 12), flexion (n = 12) or global (n = 15). Revisions were done because of isolated instability. Revision consisted in implant revision using a CCK (n = 42), a hinge prosthesis (n = 12) or an isolated polyethylene insert exchange (n = 8). Patients were assessed at one year by the difference between the preoperative Oxford Knee Score (OKS) and the score at one year postoperatively. The results were deemed satisfactory if the variation between preoperative OKS and one-year follow-up was greater than or equal to 5 points (Minimal Clinically Important Difference (MCID) following TKA). Complication rate and risk factors influencing the outcome were also analyzed. Of the 62 patients, 59 could be assessed at one year using postoperative OKS (one death at 0.66 years from unrelated reason, and two had repeated revision within one year postoperative [1 aseptic loosening and 1 Co-Cr allergy]). Preoperative OKS was 15.5 points ± 7.1 (range, 2-37), rising to 28.9 points ± 8.7 (range, 11-45) at follow-up. The mean OKS improvement was 13.4 points ± 10.3 (range, -8 to 33) (p < 0.001) and 47 patients (79.6%) reached the MCID at follow-up. Female gender was associated with a worse evolution of OKS (-5.8, 95% CI: -11.26 to -0.34 (p = 0.038)). In contrast, there was no significant difference in the evolution of the OKS according to the type of TFI in extension or in flexion, in midflexion or global (p = 0.5). Likewise, there was no significant difference in the evolution of the OKS between RTKA using CCK, hinged prosthesis or isolated polyethylene insert exchange (p = 0.3). There was no recurrence of instability at final follow-up (3.04 years ± 1.5 (range, 0.66-6.25)). Revision for instability did not drive to stiffness since mean flexion prior to RTKA was 116 ° ± 13 ° (range, 90 ° to 130 °) versus 116.7 ° ± 12 ° (range, 90 ° to 130 °) at follow-up. Fourteen patients (22.6%) experienced postoperative complications, including 3 revisions (4.8%) at final follow-up. RTKA for TFI leads to significant functional improvement at one-year postoperative. However, the risk of complications is almost high at 22.6%. IV; retrospective study.

Labouyrie A ，Dаrtus J ，Putman S ，Trouillez T ，Migаud H ，Pаsquier G ... -  《Orthopaedics & Traumatology-Surgery & Research》

No Difference in 10-year Clinical or Radiographic Outcomes Between Kinematic and Mechanical Alignment in TKA: A Randomized Trial.

There is continuing debate about the ideal philosophy for component alignment in TKA. However, there are limited long-term functional and radiographic data on randomized comparisons of kinematic alignment versus mechanical alignment. We present the 10-year follow-up findings of a single-center, multisurgeon randomized controlled trial (RCT) comparing these two alignment philosophies in terms of the following questions: (1) Is there a difference in PROM scores? (2) Is there a difference in survivorship free from revision or reoperation for any cause? (3) Is there a difference in survivorship free from radiographic loosening? Ninety-nine patients undergoing primary TKA for osteoarthritis were randomized to either the mechanical alignment (n = 50) or kinematic alignment (n = 49) group. Eligibility for the study was patients undergoing unilateral TKA for osteoarthritis who were suitable for a cruciate-retaining TKA and could undergo MRI. Patients who had previous osteotomy, coronal alignment > 15° from neutral, a fixed flexion deformity > 15°, or instability whereby constrained components were being considered were excluded. Computer navigation was used in the mechanical alignment group, and patient-specific cutting blocks were used in the kinematic alignment group. At 10 years, 86% (43) of the patients in the mechanical alignment group and 80% (39) in the kinematic alignment group were available for follow-up performed as a per-protocol analysis. The PROMs that we assessed included the Knee Society Score, Oxford Knee Score, WOMAC, Forgotten Joint Score, and EuroQol 5-Dimension score. Kaplan-Meier analysis was used to assess survivorship free from reoperation (any reason) and revision (change or addition of any component). A single blinded observer assessed radiographs for signs of aseptic loosening (as defined by the presence of progressive radiolucent lines in two or more zones), which was reported as survivorship free from loosening. At 10 years, there was no difference in any PROM score measured between the groups. Ten-year survivorship free from revision (components removed or added) likewise did not differ between the groups (96% [95% CI 91% to 99%] for the mechanical alignment group and 91% [95% CI 83% to 99%] for the kinematic alignment group; p = 0.38). There were two revisions in the mechanical alignment group (periprosthetic fracture, deep infection) and four in the kinematic alignment group (two secondary patella resurfacings, two deep infections). There was no statistically significant difference in reoperations for any cause between the two groups. There was no difference with regard to survivorship free from loosening on radiographic review (χ 2 = 1.3; p = 0.52) (progressive radiolucent lines seen at 10 years were 0% for mechanical alignment and 3% for kinematic alignment). Like the 2-year and 5-year outcomes previously reported, 10-year follow-up for this RCT demonstrated no functional or radiographic difference in outcomes between mechanical alignment and kinematic alignment TKA. Anticipated functional benefits of kinematic alignment were not demonstrated, and revision-free survivorship at 10 years did not differ between the two groups. Given the unknown long-term impact of kinematic alignment with regard to implant position (especially tibial component varus), we must conclude that mechanical alignment remains the reference standard for TKA. We could not demonstrate any advantage to kinematic alignment at 10-year follow-up. Level I, therapeutic study.

Gibbons JP ，Zeng N ，Bayan A ，Walker ML ，Farrington B ，Young SW ... -  《-》

Erratum: Eyestalk Ablation to Increase Ovarian Maturation in Mud Crabs.

《Jove-Journal of Visualized Experiments》

What Are the Functional, Radiographic, and Survivorship Outcomes of a Modified Cup-cage Technique for Pelvic Discontinuity?

Pelvic discontinuity (PD) presents a complex challenge in revision hip arthroplasty. The traditional cup-cage construct, which involves a screw-secured porous metal cup and an overlying antiprotrusio cage, has shown promising mid- to long-term results. However, there is limited information on the outcomes of modifications to the original technique. Our study aims to evaluate a modified technique in which the cup position is determined by the placement of the overlying cage, allowing for adjustments to achieve optimal orientation. Among patients treated for PD with a cup-cage construct in which the cup position was dictated by the position of the cage: (1) What are Harris hip scores achieved at a minimum of 2 years of follow-up? (2) What is the Kaplan-Meier survivorship free from aseptic loosening or component migration? (3) What is the Kaplan-Meier survivorship free from revision for any reason? (4) What surgical complications are associated with the procedure? Between October 2013 and January 2022, we performed 805 acetabular revisions. Among these, 33 patients with PD confirmed intraoperatively were considered potentially eligible for a cup-cage construct; no other method of surgical management was used. We performed 64% (21 of 33) of these procedures from October 2013 to January 2018, with 6% (2 of 33) of patients lost to follow-up before the minimum study follow-up of 2 years; these 19 patients were monitored over a period ranging from 70 to 115 months. A further 12 patients underwent this procedure from January 2018 to January 2022, with one lost to follow-up before the minimum study follow-up of 2 years; the other patients met the minimum 2-year follow-up requirement. The remaining 30 patients with data analyzed here (10 men, 20 women) had a mean ± SD age of 61 ± 12 years and a median BMI of 29 kg/m 2 (range 20 to 33 kg/m 2 ) at the time of revision surgery. Twenty-one patients underwent revision due to aseptic loosening, and nine due to periprosthetic joint infection (PJI). The causes of PD in our patients were as follows: cup aseptic loosening without significant osteolysis in 20% (6 of 30), where the loose cup caused erosion of the host bone, leading to PD; PJI in 30% (9 of 30); intraoperative iatrogenic PD in 3% (1 of 30); and osteolysis in 47% (14 of 30), which also resulted in aseptic loosening. The median follow-up time was 79 months (range 25 to 115 months). The Harris hip score was used to evaluate clinical outcomes, with preoperative values compared with the most recent follow-up. Radiographs were reviewed by two experienced surgeons at each follow-up visit to assess component loosening (defined as migration > 5 mm or the presence of circumferential radiolucent lines) or clear migration. PD was considered healed if bridging callus or trabecular bone was visible across the site of the discontinuity. Complications were assessed through a comprehensive review of electronic medical records. Kaplan-Meier analysis was used to estimate implant survivorship and radiographic loosening, with aseptic loosening or component migration as the endpoint, as well as survivorship free from any reoperation. The Harris hip score improved from a median of 39 (range 30 to 66) preoperatively to a median of 76 (range 30 to 90) postoperatively (median difference 33 [range 2 to 48]; p < 0.01). Within the limitations of two-dimensional (2D) radiographic imaging, successful bone graft integration and the healing of PD were noted in 83% (25 of 30) of patients. Kaplan-Meier survivorship free from radiographic signs of aseptic loosening or component migration was 100% (95% CI 100% to 100%) at 115 months. When any revision related to the acetabular component was considered the endpoint, survivorship free from acetabular component revision at 115 months after revision surgery was 100% (95% CI 100% to 100%). When the need for any reoperation was considered the endpoint, survivorship free from needing reoperation at 115 months after revision surgery was 85% for all patients (95% CI 73% to 100%). When including only patients with a follow-up time of > 4 years (20 of 30), survivorship free from needing reoperation at 115 months after revision surgery was 90% (95% CI 78% to 100%). Postoperative complications during the follow-up period included one early dislocation on the fifth day after surgery, treated with closed reduction and 6 weeks of abduction bracing. One femoral stem loosening occurred at 56 months postoperatively, although the acetabular component remained securely fixed; this patient declined revision surgery. One patient experienced a dislocation 5 months after surgery but refused treatment and opted for prolonged bed rest. Additionally, one patient underwent a debridement, antibiotics, and implant retention procedure 1 week after the revision surgery and subsequently showed no signs of infection at the latest follow-up, 38 months postoperatively. Our study highlights the effectiveness of a modified cup-cage technique in complex hip revisions, showing promising results in terms of construct survivorship and low complication rates. Surgeons could consider delaying screw fixation until after positioning the cage within the porous cup to allow for optimal adjustment and using metal augments for severe bone defects to achieve better alignment. Surgeon experience with the cup-cage technique is crucial for achieving optimal outcomes. Future studies should focus on long-term follow-up visits to assess the durability and effectiveness of these modifications and explore the comparative effectiveness versus other methods, such as custom triflange components and jumbo cups with distraction. Level III, therapeutic study.

Mu W ，Xu B ，Wahafu T ，Wang F ，Guo W ，Zou C ，Cao L ... -  《-》

Kinematic Alignment Does Not Result in Clinically Important Improvements After TKA Compared With Mechanical Alignment: A Meta-analysis of Randomized Trials.

There is debate as to whether kinematic TKA or mechanical alignment TKA is superior. Recent systematic reviews have suggested that kinematically aligned TKAs may be the preferred option. However, the observed differences in alignment favoring kinematic alignment may not improve outcomes (performance or durability) in ways that patients can perceive, and likewise, statistical differences in outcome scores sometimes observed in clinical trials may be too small for patients to notice. Minimum clinically important differences (MCIDs) are changes that are deemed meaningful to the patient. A meta-analysis of randomized trials that frames results on this topic in terms of MCIDs may therefore be informative to surgeons and their patients. (1) Does kinematic alignment for TKA insertion improve patient-reported outcome measures (PROMs) by clinically important margins (for example, 5 points of 48 on the adjusted Oxford Knee Score [OKS] or 13.7 points of 100 on the Forgotten Joint Score [FJS]) compared with mechanical alignment? (2) Does kinematic alignment for TKA insertion improve ROM by a clinically important margin (defined as 3.8° to 6.4° in flexion) compared with mechanical alignment? A systematic review of Medline and Embase databases was performed from inception to January 29, 2023, the date of search. We identified RCTs comparing mechanical alignment TKA with kinematic alignment TKA. All English-language RCTs comparing PROMs data in kinematic versus mechanical alignment TKAs performed in patients 18 years or older were included. Studies that were not in English, involved overlapping reports of the same trial, and/or utilized nonrandomized controlled trial methodology were excluded. Conference abstracts or study protocols, pilot studies, and review articles were also excluded. Two reviewers screened abstracts, full-text, and extracted data and assessed included studies for risk of bias using the Cochrane Risk of Bias tool, version 2. Twelve randomized controlled trials (RCTs) were identified, which included 1033 patients with a mean age of 68 years (range 40 to 94) from eight countries who were undergoing primary TKA. Six studies were determined to be low risk of bias, with the remaining six studies were determined to be of moderate-to-high risk of bias. As a result, we would expect that the included studies might overestimate the benefit of the newer approach. Outcomes included ROM and PROMs. Where feasible, pooled analysis was completed. PROMs data were extracted from nine pooled studies, with a randomized n = 443 in the kinematic alignment group and n = 435 in the mechanical alignment group. ROM data were extracted from six pooled studies, with randomized n = 248 in the kinematic alignment group and n = 243 in the mechanical alignment group. PROMS were converted to common scales where possible. Multiple versions of the OKS exist; therefore, OKS scores were converted if needed to a 0 to 48 Oxford scale, in which higher scores represent better clinical outcomes. WOMAC scores were converted to OKS using previously reported techniques. The OKS and converted WOMAC scores were represented as "functional scores" in our data set because of their conversion. An MCID of 5 was utilized as previously documented for the OKS. Heterogeneity was assessed using the I2 statistic, and for an I2 of > 25%, random-effects models were utilized. In nine pooled studies, we found no clinically important difference between the kinematic and mechanical alignment groups in terms of our generated functional score (mean difference 3 of possible 48 [95% confidence interval (CI) 0.81 to 4.54]; p = 0.005). The functional score included OKS and WOMAC scores converted to OKS. The difference did not exceed the MCID for the OKS. In three pooled studies, we found no difference between the kinematic and mechanical alignment groups in terms of FJS at 1 to 2 years (mean difference 4 of possible 200 [95% CI -1.77 to 9.08]; p = 0.19). In three pooled studies, we found no difference between the kinematic and mechanical alignment groups in terms of EuroQol 5-domain instrument VAS score at 1 to 2 years (mean difference 0.2 of possible 100 [95% CI -3.17 to 3.61]; p = 0.90). We found no clinically meaningful difference between kinematic TKA and mechanical alignment TKA for ROM (extension mean difference 0.1° [95% CI -1.08 to 1.34]; p = 0.83, and flexion mean difference 3° [95% CI 0.5 to 5.61]; p = 0.02). This meta-analysis found no clinically important benefit favoring kinematic over mechanical alignment in TKA based on the available RCTs. Because patients cannot perceive advantages to kinematic alignment, and because it adds costs, time (if using advanced technologies), and potential risks to the patient that are associated with novelty, it should not be widely adopted in practice until or unless such advantages have been shown in well-designed RCTs. Level I, therapeutic study.

Nucci N ，Chakrabarti M ，DeVries Z ，Ekhtiari S ，Tomescu S ，Mundi R ... -  《-》