Total and unicondylar knee arthroplasty are equivalent treatment options in end-stage spontaneous osteonecrosis of the knee, and the size of the lesion has no influence on the results

Bone cysts at the meniscal attachment are associated with a longer symptom duration among patients with arthroscopically treated medial meniscus posterior root tear

PURPOSE

To elucidate the features of bone cysts at attachment sites of medial meniscus posterior root tears (MMPRTs).

METHODS

Knees treated using arthroscopic surgery for MMPRT between 2015 and 2022 were retrospectively reviewed. Patients without a memory of onset (painful popping), prior knee surgeries, concomitant ligament or meniscus injuries or fractures were excluded. Duration from onset to magnetic resonance imaging (MRI) and type of tear were evaluated during arthroscopy. On radiography, meniscus signs (cleft/ghost/giraffe neck), bone cysts at the attachment site of the MMPRT and posterior shiny-corner lesions (PSCLs; bone marrow lesions on the meniscal-covered portion of the posterior tibial plateau) were evaluated. The sensitivity and specificity of the bone cysts were assessed by comparison with matched patients who underwent arthroscopic surgery for medial meniscus posterior horn tear. In addition, subgroups (cyst-positive/cyst-negative) among patients with MMPRT were created to assess the features of bone cysts.

RESULTS

A total of 275 patients with MMPRT and 275 matched patients with posterior horn tears were evaluated. The sensitivity and specificity of bone cysts for MMPRT in this study were 22.2% and 98.6%, respectively. Among the 275 knees with MMPRT, compared with the cyst-negative group, the cyst-positive group had a longer duration from onset to MRI (12.9 ± 13.1 vs. 8.3 ± 10.9 weeks, respectively, p = 0.025) and reduced occurrence of PSCLs (18.0% vs. 42.0%, respectively, p = 0.031).

CONCLUSION

The occurrence of bone cysts at the attachment site was helpful for the accurate diagnosis of MMPRT and related to longer duration from onset to MRI and reduced PSCLs.

LEVEL OF EVIDENCE

Level III, cross-sectional study.

Osteoporosis, Osteoarthritis, and Subchondral Insufficiency Fracture: Recent Insights

The increased incidence of osteoarthritis (OA), particularly knee and hip OA, and osteoporosis (OP), owing to population aging, have escalated the medical expense burden. Osteoarthritis is more prevalent in older women, and the involvement of subchondral bone fragility spotlights its association with OP. Notably, subchondral insufficiency fracture (SIF) may represent a more pronounced condition of OA pathophysiology. This review summarizes the relationship between OA and OP, incorporating recent insights into SIF. Progressive SIF leads to joint collapse and secondary OA and is associated with OP. Furthermore, the thinning and fragility of subchondral bone in early-stage OA suggest that SIF may be a subtype of OA (osteoporosis-related OA, OPOA) characterized by significant subchondral bone damage. The high bone mineral density observed in OA may be overestimated due to osteophytes and sclerosis and can potentially contribute to OPOA. The incidence of OPOA is expected to increase along with population aging. Therefore, prioritizing OP screening, early interventions for patients with early-stage OA, and fracture prevention measures such as rehabilitation, fracture liaison services, nutritional management, and medication guidance are essential.

Functional improvement of unicompartmental knee arthroplasty compared with total knee arthroplasty for subchondral insufficiency fracture of the knee

Subchondral insufficiency fracture of the knee (SIFK) causes acute knee pain in adults and often requires surgical management. Unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) are the two most common surgical treatments for SIFK. While both UKA and TKA have their advantages, there is no consensus for SIFK localized on the medial compartment. We hypothesized that patients with SIFK treated with UKA would show superior patient-reported outcomes compared to those who underwent TKA. A total of 90 patients with SIFK located medially were included in the TKA (n = 45) and UKA (n = 45) groups. Size of SIFK lesions were measured on MR images. Patient reported outcomes in the form of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Hospital Special Surgery (HSS) scores, and Knee Society Scores (KSS) were assessed preoperatively, postoperative 6, 12 months, and at the final follow-up. There were no differences in the size of the SIFK lesion between two groups. At 6 months, WOMAC score was better in the UKA group than the TKA group (p < .01). Both groups had a significant improvement in WOMAC, HSS, and KSS scores at the final follow-up compared to preoperative scores. The UKA group had better range of motion of the knee preoperatively and postoperatively than the TKA group (p < .01 and p < .01). UKA group showed a higher relative risk than the TKA group in terms of complications (RR = 3.0) but with no statistical significance (P = 0.31). Unicompartmental arthroplasty and total joint arthroplasty can produce successful outcomes in patients with SIFK with proper patient selection, regardless of the size of SIFK lesion.

The impact of preoperative MRI-detected lateral meniscal intra-substance signal abnormalities on mid-term functional outcomes following mobile-bearing unicompartmental knee arthroplasty

PURPOSE

There is a dilemma as to whether the presence of degenerative changes of lateral meniscus is a contraindication to medial unicompartmental knee arthroplasty (UKA). Therefore, the purpose of this study is to assess the influence of preoperative MRI-detected lateral meniscal intra-substance signal abnormalities on mid-term functional outcomes following mobile-bearing UKA.

METHODS

We performed a retrospective review of the record on a consecutive series of patients who have undergone mobile-bearing medial UKA from September 2020 to June 2023. The mean duration of follow-up was 2.34 years. All records were collected from case system. MRI assessment of lateral meniscus was performed with the use of the Stoller's classification system. Patients were categorized into two groups (grade 0 and ≥ grade 1). Patient-reported outcomes were assessed with the use of the American Knee Society functional Score (AKSS-F), American Knee Society Objective Score (AKSS-O), and Oxford Knee Score (OKS) preoperatively and at latest follow-up. Furthermore, range of motion (ROM) and hip-knee-ankle angle (HKA) were measured in preoperative and postoperative periods.

RESULTS

A total of 92 patients (101 knees) were included in our study. No differences in AKSS-F, AKSS-O, OKS, HKA, or ROM were found between those who showed normal or abnormal signal change of lateral meniscus preoperatively (P < 0.05). Furthermore, there were also no significant differences between two groups concerning AKSS-F, AKSS-O, OKS, HKA, or ROM at latest postoperative follow-up (P < 0.05). Age and duration of disease were independent predictors of low postoperative AKSS-F and AKSS-O (P < 0.05). Nevertheless, ROM was an independent predictor of high postoperative AKKS-O (P < 0.05). Age and female were independent predictors of high postoperative OKS (P < 0.05).

CONCLUSION

The presence of preoperative MRI-detected lateral meniscal degenerative changes did not affect mid-term functional outcomes in patients who underwent mobile-bearing medial UKA. On the basis of the results of the current study, we believe that the presence of degenerative changes of lateral meniscus is acceptable in mobile-bearing medial UKA.

How to Perform Better on Oxford UKA? A Technical Note from over 500 Surgical Experiences

Oxford unicompartmental knee arthroplasty (UKA) has been particularly prevalent because the concept of knee preservation is deeply rooted in people's minds. Mobile bearing UKA is a surgical type of UKA with considerable advantages. This note describes some surgical techniques, including patient position, surgical field exposure, selection of the size of the prosthesis, sagittal tibial osteotomy, placement of the femoral prosthesis and gap balance, to assist surgeons with less experience in performing these operations successfully. The techniques described in this note have been used in over 500 Oxford UKA cases, and nearly 95% patients achieved good prosthesis position and satisfactory postoperative outcome. We hope that the empirical summaries from numerous cases will help surgeons to learn Oxford UKA quickly and effectively, driving the spread of the technique and benefiting more patients.

A systematic review and meta-analysis comparing outcomes following total knee arthroplasty for rheumatoid arthritis versus for osteoarthritis

PURPOSE

Total knee arthroplasty (TKA) in patients with osteoarthritis (OA) are considered to be a successful procedure, but with little being known about outcomes in patients with rheumatoid arthritis (RA). The aim of this study was to compare the outcomes of TKA in patients with RA versus OA.

METHODS

Data were obtained from PubMed, Cochrane Library, EBSCO and Scopus for all available studies comparing the outcomes of THA in RA and OA patients (From January 1, 2000 to October 15, 2022). Outcomes of interest included infection, revision, venous thromboembolism (VTE), mortality, periprosthetic fractures, prosthetic loosening, length of stay, and satisfaction. Two reviewers independently assessed each study for quality and extracted data. The quality of the studies was scored using the Newcastle-Ottawa scale (NOS).

RESULTS

Twenty-four articles with a total 8,033,554 patients were included in this review. The results found strong evidence for increased risk of overall infection (OR = 1.61, 95% CI, 1.24-2.07; P = 0.0003), deep infection (OR = 2.06, 95% CI, 1.37-3.09; P = 0.0005), VTE (OR = 0.76, 95% CI, 0.61-0.93; P = 0.008), pulmonary embolism (PE) (OR = 0.84, 95% CI, 0.78-0.90; P<0.00001), periprosthetic fractures (OR = 1.87, 95% CI, 1.60-2.17; P<0.00001); and reasonable evidence for increased risk of deep venous thrombosis (DVT) (OR = 0.74, 95% CI, 0.54-0.99; P = 0.05), and length of stay (OR = 0.07, 95% CI, 0.01-0.14; P = 0.03) after TKA in patients with RA versus OA. There were no significant differences in superficial site infection (OR = 0.84,95% CI, 0.47-1.52; P = 0.57), revision (OR = 1.33,95% CI, 0.79-2.23; P = 0.28), mortality (OR = 1.16,95% CI, 0.87-1.55; P = 0.32), and prosthetic loosening (OR = 1.75, 95% CI, 0.56-5.48; P = 0.34) between the groups.

CONCLUSION

Our study demonstrated that patients with RA have a higher risk of postoperative infection, VTE, periprosthetic fracture, and lengths of stay, but did not increase revision rate, prosthetic loosening and mortality compared to patients with OA following TKA. In conclusion, despite RA increased incidence of postoperative complications, TKA should continue to be presented as an effective surgical procedure for patients whose conditions are intractable to conservative and medical management of RA.

Unicompartmental knee arthroplasty (UKA) for primary spontaneous osteonecrosis of the knee (SONK): a systematic review

Introduction

The role of unicompartmental knee arthroplasty (UKA) in spontaneous osteonecrosis of the knee (SONK) is still controversial.

Materials and methods

We performed a systematic review to evaluate all available current literature on UKA in the setting of SONK. A comprehensive electronic research was performed using the PubMed, Embase, Web of Science, and Cochrane databases with keywords related to SONK and knee arthroplasty. Studies were selected with predetermined inclusion criteria: 1) studies that specifically assessed SONK treated with UKA; 2) studies reporting implant survival rate and global clinical outcomes; 3) studies with a minimum follow up of 1 year. We excluded articles not written in English, articles that did not differentiate between primary and secondary osteonecrosis and articles published before 2000.

Results

The overall research process produced 19 studies. We extrapolated data of a total of 717 unicompartimental knee arthroplasty procedures (1,39% lateral UKA, 98,61% medial UKA). Extracted data include years of follow-up, patient demographics, laterality of lesion, radiological findings, unicompartimental knee arthroplasty implants, reason of revision, revision rate, maximum knee flexion, knee clinical outcomes score, and Kaplan-Meier survival curves. The data collected show that UKA had acceptable survival rates as well as revision rates and good clinical outcomes both in the short- and long-term.

Conclusion

UKA is an optimal treatment choice for primary SONK when correctly indicated in a carefully selected subset of patients, with no significant difference compared to osteoarthritis. Attention must be paid to distinguish the primary from secondary SONK, as the latter could lead to worse outcomes.

Changes in epidemiological characteristics of knee arthroplasty in eastern, northern and central China between 2011 and 2020

OBJECTIVE

To explore changes in the epidemiological and clinical characteristics of patients who underwent knee arthroplasty (KA) over a 10-year period in China.

METHODS

Medical records of patients with knee osteoarthritis (KOA), who underwent primary unilateral KA in 5 level I center hospitals in China between January 2011 and December 2020, were retrospectively reviewed and analyzed. To more clearly define changes over the years, patients were divided into two groups according to time of admission at 5-year intervals. Age, sex, body mass index (BMI), Kellgren-Lawrence (K-L) classification, comorbid diseases, surgical procedures, hospital stay, and hospitalization costs were compared between the two groups.

RESULTS

A total of 23,610 patients with KOA (5400 male and 18,210 females; mean age: 65.7 ± 7.6 years) who underwent primary unilateral KA were included. The number of KAs increased in recent years (group A, n = 7606 vs. group B, n = 16,004). Significant differences were noted in age, sex, BMI, K-L classification, comorbidities, surgical procedures, hospital stay, and hospitalization costs between the two periods (P < 0.05). More than three-quarters of KA cases involved females, and the age at surgery tended to be younger than that reported in foreign countries. In group B, the proportion of overweight and grade III, number of comorbidities, and unicompartmental knee arthroplasty patients increased compared to that in group A; however, hospitalization costs and length of hospital stay decreased.

CONCLUSIONS

Results suggested that the epidemiological characteristics of patients undergoing KA have changed over time. An analysis of the epidemiological characteristics of patients undergoing KA treatment may provide a scientific basis for the prevention and control of KOA.

A Case of Subchondral Insufficiency Fracture of the Knee at Lateral Femoral Condyle Treated With Unicompartmental Knee Arthroplasty

Spontaneous insufficiency fracture of the knee is a potentially devastating yet poorly understood disease entity that can lead to secondary osteoarthritis. Most cases involve the medial femoral condyle, and the lateral femoral condyle is rarely affected. The optimal treatment for spontaneous insufficiency fracture of the lateral femoral condyle remains undetermined, and there are no previous dedicated reports on treatment outcome with unicompartmental knee arthroplasty. A middle-aged lady presented with subacute left knee pain and a locked knee. Subsequent imaging studies revealed a spontaneous insufficiency fracture of the lateral femoral condyle. In view of the isolated compartment involvement, unicompartmental knee arthroplasty was performed with satisfactory outcome. At 1 year postoperatively, the patient had complete resolution of knee pain and was able to resume working.

Bisphosphonate for spontaneous osteonecrosis of the knee: A protocol for systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Bisphosphonates are commonly used to treat spontaneous osteonecrosis of the knee (SONK), while there are no relevant systematic review or meta-analysis designed to evaluate the effects of bisphosphonates on SONK.

METHODS

We will identify relevant randomized controlled trials from the PubMed, EMBASE, CINAHL and China National Knowledge Infrastructure, up to March 20, 2020. Data that meets the inclusion criteria will be extracted and analyzed using RevMan V.5.3 software. Two reviewers will assess quality of the included studies by using the Cochrane Collaboration risk of bias tool. Egger test and Begg test will be used to evaluate publication bias. And Grading of Recommendations Assessment, Development and Evaluation will be employed to assess the quality of evidence.

RESULTS

In this study, we will analyze the effect of bisphosphonates on pain intensity, physical function, biochemical including alkaline phosphatase, N-terminal propeptide of type I procollagen, and C-terminal type I collagen telopeptide, radiological outcome (evaluated by using Magnetic resonance imaging) and ratio of secondary surgery for patients with SONK.

CONCLUSION

Our findings will provide evidence for the effectiveness and potential treatment prescriptions of bisphosphonates acupuncture for patients affected by SONK.