Bone & Joint Journal最新文献

Aims: Evaluating plantar pressure distribution and coronal lower limb alignment, including the hindfoot, using the hip-to-calcaneus axis, known as the ground mechanical axis (GA), is valuable in total knee arthroplasty (TKA). This study aimed to compare postoperative changes in plantar pressure distribution and lower limb alignment between mechanically aligned TKA (MA-TKA) and ground kinematically aligned TKA (gKA-TKA), targeting neutral GA.

Methods: After 1:1 propensity score matching, 35 pairs of patients with end-stage osteoarthritis of the knee, who underwent gKA-TKA and MA-TKA with similar preoperative disability between September 2019 and March 2022, were compared. Plantar pressure distribution during walking and unipedal stance was measured preoperatively and one year postoperatively using a pressure plate. The hip-knee-calcaneus angle (HKC) (positive values = valgus) and the percentage of the GA passing position at the knee joint (%GA; medial edge, 0%; lateral edge, 100%) were assessed on long-leg radiographs in unipedal stance.

Results: MA-TKA showed a medial loading pattern in the hindfoot. gKA-TKA exhibited a nearly equal pressure distribution in the coronal plane of the hindfoot. Postoperative centre-of-pressure path length during unipedal stance was significantly better for gKA-TKA than MA-TKA (p = 0.043). Furthermore, mean HKC angle and mean %GA of the MA-TKA were 2.0° (SD 2.4°) and 54.2% (SD 9.0%), respectively; those of the gKA-TKA were -0.2° (SD 1.0°) and 49.6% (SD 5.0%), respectively. Significant correlations were observed between the HKC angle (r = 0.391 (95% CI 0.172 to 0.573)) or %GA (r = 0.343 (95% CI 0.117 to 0.535)) and the hindfoot plantar pressure pattern in the coronal plane, indicating that postoperative lower limb valgus deformity in the hip-to-calcaneus axis results in a medial loading pattern.

Conclusion: gKA-TKA can provide more neutral weightbearing in the GA, more equal coronal hindfoot pressure during walking, and improved stability in unipedal stance compared with MA-TKA.

Aims: Two-stage exchange arthroplasty is frequently used to treat periprosthetic hip infection. Nevertheless, particularly in high-risk patients, there has been increased attention towards single-surgery options such as 1.5-stage exchange. Therefore, we sought to compare 1.5- and two-stage patients and determine: 1) baseline demographic details, comorbidities, infection, surgical, and inpatient characteristics; 2) re-revision rates and causes, hip pain and implant loosening of surviving implants, success/failure according to the Musculoskeletal Infection Society (MSIS) outcome reporting tool, and mortality at latest follow-up; and 3) whether the type of surgery (1.5- vs two-stage) is a re-revision predictor.

Methods: We undertook a retrospective review of 73 patients who underwent either 1.5-stage stem hybrid fixation (n = 43) or two-stage exchange hip arthroplasty (n = 30) at a single institution (March 2019 to May 2023). Demographic information and variables of interest were compared between groups. Predictors of re-revision were assessed with logistic regression. The mean follow-up was 454 days (23 to 1,620).

Results: Our cohorts were not significantly different, except for a higher proportion of 1.5-stage patients classified as American Society of Anesthesiologists (ASA) grade III or IV (77% vs 50%; p = 0.025). There were more prior revisions among 1.5-stage patients (mean 1.5 vs 0.7; p = 0.012), whereas mean length of follow-up and mean operating time were significantly longer among two-stage patients (650 vs 317 days, p = 0.002; and 501.3 (360 to 660) vs 267.2 mins (150 to 420), p < 0.001, respectively). In the 1.5-stage group, there was a significantly higher proportion of periprosthetic infections as a cause of re-revision (80% vs 0%; p = 0.011). Postoperative success or failure (MSIS outcome) and mortality rates were not statistically significantly different. The type of surgery was not a significant re-revision predictor.

Conclusion: Our preliminary data suggest that our selective prescription of 1.5-stage revision was associated with significantly more re-revisions due to infection when compared with two-stage patients. We acknowledge the potential benefits of the 1.5-stage strategy, especially among high-risk patients, as it involves a single operation; however, higher reinfection rates must be considered when counselling these patients.

Aims: Ceramic-on-ceramic (CoC) articulations in total hip arthroplasty (THA) have the advantage of low wear but the unique risk of fracture. After revision for CoC-bearing fracture, third-body ceramic particles can lead to massive wear of cobalt-chrome (CoCr) bearings, causing extremely elevated blood cobalt. We present a multicentre series of five cases where patients sustained fractures of ceramic liners, were revised using a CoCr articulation, and rapidly developed severe cobalt toxicity.

Methods: We identified five cases of cobalt toxicity after fractured CoC THA treated with revision to CoCr on polyethylene bearings. Mean follow-up was three years (5 to 72 months) after re-revision to remove the CoCr bearing.

Results: Symptoms of cobalt toxicity occurred at a mean ten months (6 to 12) after revision for ceramic fracture. All patients developed vision and hearing loss, balance difficulties, and peripheral neuropathy. Several had cardiomyopathy, endocrine abnormalities, and local skin discolouration. Only two reported hip pain. Repeat revision for recognized cobalt toxicity occurred at a mean 22 months after revision for ceramic fracture. Mean serum cobalt level at re-revision was 991 ng/ml (normal value < 1 ng/ml; 734 to 1,302). All CoCr femoral heads exhibited massive wear, and deep tissues showed prominent metal staining. Treatment consisted of debridement and revision to a ceramic femoral head with highly cross-linked polyethylene (HXLPE) liner. Serum cobalt improved to a mean 25 μg/l (1 to 76) at final follow-up. All patients reported partial improvement in vision and hearing, however their peripheral neuropathy and balance difficulties did not recover.

Conclusion: Systemic cobalt toxicity is a devastating complication of ceramic-bearing fracture in THA treated with CoCr bearings, which may not present with hip symptoms. The diagnosis of this syndrome of systemic cobalt toxicity was significantly delayed following systemic symptoms in this series. Debridement and re-revision to a ceramic-on-HXLPE bearing leads to improvement, but not full resolution, of cobalt toxicity complications.

Aims: This study investigates the relationship between diabetes mellitus (DM), glycated haemoglobin (HbA1c), and postoperative outcomes among patients undergoing hip and knee arthroplasty.

Methods: We conducted a single-centre cohort study of patients who underwent primary hip or knee arthroplasty between June 2008 and December 2019 and for whom preoperative HbA1c had been recorded. Cases were categorized by preoperative HbA1c as 'diabetes' (≥ 48 mmol/mol), 'prediabetes' (≥ 42 mmol/mol and < 48 mmol/mol), 'no diabetes' (< 42 mmol/mol), or in 'remission' (preoperative HbA1c < 42 mmol/mol but having a historic HbA1c result ≥ 42 mmol/mol). Multivariable logistic regression and restricted cubic splines were used to examine the association between diabetes status, HbA1c, and early postoperative outcomes.

Results: Analysis of 9,454 procedures (18.4% diabetes, 23.5% prediabetes, 49.7% no diabetes, 8.4% in remission) revealed that DM was associated with a 50% greater likelihood of experiencing one or more postoperative complications (odds ratio (OR) 1.47 (95% CI 1.26 to 1.71)), a 60% greater risk of acute kidney injury or electrolyte abnormality (OR 1.57 (95% CI 1.33 to 1.87)), and more than double the risk of postoperative urinary tract infection (OR 2.25 (95% CI 1.15 to 4.52)) and deep surgical site infection (OR 2.03 (95% CI 1.05 to 3.86)) compared to individuals without diabetes. There was a substantial increase in complication risk as HbA1c entered prediabetes range with no evidence of a plateau or threshold effect, and a profound reduction in the risk of almost all recorded complications for patients in remission from previously elevated HbA1c.

Conclusion: DM was associated with an increased risk of almost all measured early postoperative complications. Interventions to reduce elevated HbA1c, to any degree, may benefit patient outcomes, however these must be balanced with the risk of iatrogenic harm.

Aims: Periprosthetic femoral fractures (PPFFs) around total hip arthroplasty (THA) stems are challenging. Typically, loose stems are revised, while well-fixed implants undergo fracture open reduction and internal fixation. Determining implant fixation status preoperatively is important. The purpose of this study was to define the accuracy of predicting the status of preoperative stem fixation using radiography and CT.

Methods: A total of 24 patients with Vancouver B-type PPFF with preoperative radiography and CT scans were included. Patients with obviously loose implants (detached or subsided stem), fractures that occurred within 90 days of index THA, and cemented femoral components were excluded. Two fellowship-trained adult reconstruction surgeons and two traumatologists reviewed radiographs and predicted stem fixation status. They then evaluated CT scans, and fixation status was reassessed. Each surgeon undertook two evaluations one month apart. The correct response was determined by intraoperative findings. Interobserver and intraobserver reliability values were calculated, as well as validity.

Results: Overall, 15 implants (62.5%) were well-fixed and nine (37.5%) were loose. Radiography alone predicted correct fixation status in 53.1% of cases (102/192). When adding CT, correct predictions improved to 54.7% (105/192). Fixation status predictions were changed in 18.2% of cases (35/192) after reviewing CT scans: 8.3% (16/192) from correct to incorrect, and 9.9% (19/192) from incorrect to correct. Interobserver reliability ranged from poor to moderate agreement, and intraobserver reliability demonstrated moderate agreement for all raters. No difference in accuracy was noted between adult reconstruction or trauma surgeons.

Conclusion: The ability to predict fixation status for PPFFs around uncemented femoral components remains challenging. The addition of preoperative CT did not significantly improve accuracy. Intraoperative testing of femoral component fixation status is essential to determine if revision or fixation is appropriate. Preoperative CT for Vancouver B PPFF does not significantly improve accuracy in assessing stem fixation status compared with plain radiography.

Aims: The aim of this study is to describe a deep muscle-sparing vastus lateralis (VL) flap to gluteus medius (Gmed) transfer to address severe hip abductor function deficiency, and present the early results achieved through a multidisciplinary team (MDT) approach.

Methods: Seven patients, with and without previous total hip arthroplasty, with severe abductor deficiency of the hip (Medical Research Council ≤ 2/5), and requiring walking aids, underwent a deep muscle-sparing VL translation flap to Gmed as part of a new orthopaedic and plastic MDT approach, and had more than 12 months' follow-up. The fatty infiltration of the glutei had a median Goutallier scale of 4 (IQR 1 to 4). Five patients had prior revision surgery, two involving a proximal femoral arthroplasty. Patients underwent pre- and postoperative evaluations with clinical examination, instrumented gait analysis, surface electromyography (EMG), and MRI.

Results: All patients were satisfied with the result and could walk without support by six months after surgery. The abductor power improved to 3 to 5 out of 5 and continued to improve beyond one year after surgery. Knee extension power was not affected. EMG demonstrated that the transferred VL activated synchronously with Gmed three months postoperatively, suggesting adaptation to its new function. MRI demonstrated no fatty infiltration of the flap or the residual VL.

Conclusion: The MDT approach to hip abductor function reconstruction with VL to Gmed transfer has demonstrated potential for success, with good functional outcomes and no functional donor-site morbidity recorded to date.

Aims: This study aimed to report the surgical techniques and early clinical results of robotic arm-assisted acetabular reconstruction in revision total hip arthroplasty (THA).

Methods: Between October 2019 and May 2021, we used the Mako robotic system to perform 62 revision THAs at our hospital. This study included 54 patients who underwent robotic arm-assisted revision THA for acetabular reconstruction. Surgical techniques using the robotic system to reconstruct the acetabulum, including preoperative planning, intraoperative registration, and the accuracy of different registration methods, are reported. The accuracy between the target acetabular component orientation and final orientation was evaluated. The latest follow-up Harris Hip Score (HHS) and radiographs were analyzed.

Results: Among the 54 hips included, four types of intraoperative registration methods with different surfaces were developed and registered 65 times. The overall success rate of the registration process was 98.5%. The mean accuracy of successful registration was 0.38 mm (0.2 to 0.5). The median difference between the target and final acetabular component orientations assessed by Mako was 1.0° (-2.0° to 0.0°) for inclination and 0.0° (-1.0° to 1.0°) for anteversion. Four hips were classified as outliers for acetabular component orientation. The reconstructed centres of rotation (CORs) were slightly lower than the anatomical CORs by a mean 4.72 mm (SD 4.71), and shifted laterally by 3.92 mm (SD 4.62) on postoperative radiographs. The median HHS improved significantly from 46.0 (IQR 33.0 to 58.3) preoperatively to 89.0 (IQR 78.3 to 93.0) postoperatively (p < 0.001). The overall satisfaction rate was 86.0% (n = 50). There were no radiological failures at the latest follow-up.

Conclusion: Robotic arm-assisted revision THA provides valuable information for the analysis of bone defects to guide reconstructive strategies. Robotic arm-assisted reaming and acetabular component or augment positioning facilitates accurate component position and orientation. The radiological and preliminary clinical results of this cohort were satisfactory.

Aims: Functional alignment (FA) and adjusted mechanical alignment (aMA) are recognized techniques for performing total knee arthroplasty (TKA). The native femur rolls back further on the lateral tibial plateau than the medial side during flexion, resulting in a medial pivot pattern of movement. We have assessed whether an individualized alignment technique affects the kinematic pattern observed and the clinical outcomes, when compared to a systematic alignment technique in TKA.

Methods: A total of 60 consecutive patients were randomized to a robotically assisted TKA with either FA (n = 29) or aMA (n = 31), using a cruciate-retaining (CR) implant. After definitive implantation of the prostheses, a trial pressure monitor was inserted recording contact points between the femoral component and monitor in the medial and lateral compartments as the knee was taken through a range of motion. The kinematic pattern was observed, contact pressures measured, and patient-reported outcome measures (PROMs) assessed at 12 months.

Results: The FA-TKA group produced a medial pivot in 58.6% of cases (17/29), symmetrical rollback in 37.9% (11/29), and a lateral pivot in 3.4% (1/29). The aMA-TKA group produced a medial pivot in 19.4% of cases (6/31), symmetrical rollback in 45.2% (14/31), and a lateral pivot in 35.5% (11/31) (p < 0.001). No differences in knee balance were recorded between the two alignment groups at any flexion point. Patients with a medial pivot kinematic pattern had superior one-year PROMs in some measures. Patients producing a lateral pivot had lower Kujala scores.

Conclusion: FA CR-TKA generates an intraoperative medial pivot kinematic pattern through soft-tissue balance more often than those that use aMA. Lateral pivot kinematic patterns are more commonly found with aMA. These intraoperative kinematic patterns are related to clinical outcomes, with knees producing a medial pivot performing better than those with lateral pivot.

Aims: To evaluate the impact and risk factors of robotic-assisted surgery (RAS) on noise generation in total hip arthroplasty (THA) with ceramic-on-ceramic (CoC) bearings in comparison to conventional (CON) manual methods.

Methods: A secondary analysis of a prospective multicentre randomized controlled trial - conducted from June 2021 to July 2022 - included 74 patients with CoC bearings, equally divided between RAS and CON groups. Noise incidence, characteristics, and duration were documented. Radiological assessments and logistic regression analysis were performed to identify predictors of noise or squeaking.

Results: The incidence of overall noise complaints was higher in the CON group compared to the RAS group, with a statistically significant difference observed at the early postoperative stage. Specifically, at 14 days post-surgery, 5.4% of patients in the RAS group and 32.4% in the CON group reported noises (p = 0.008), while at 24 weeks, the rates were 5.4% and 21.6%, respectively, with no statistically significant difference (p = 0.089). RAS showed superior alignment and precision in component placement. Logistic regression analysis identified conventional surgery as a significant predictor of noise complaints (odds ratio 7.10 (95% CI 1.51 to 33.33); p = 0.013). Additionally, the probability distributions of different acetabular alignment and abduction angles were plotted and analyzed. No differences in functional status or patient-reported outcomes were found between groups.

Conclusion: RAS in THA with CoC bearings reduces the incidence and severity of noise-related complications, and is likely due to more precise and appropriate component placement, which may improve outcomes.