Re-tear after arthroscopic rotator cuff tear surgery: risk analysis using machine learning

BACKGROUND

Postoperative rotator cuff retear after arthroscopic rotator cuff repair (ARCR) is still a major problem. Various risk factors such as age, gender, and tear size have been reported. Recently, magnetic resonance imaging-based stump classification was reported as an index of rotator cuff fragility. Although stump type 3 is reported to have a high retear rate, there are few reports on the risk of postoperative retear based on this classification. Machine learning (ML), an artificial intelligence technique, allows for more flexible predictive models than conventional statistical methods and has been applied to predict clinical outcomes. In this study, we used ML to predict postoperative retear risk after ARCR.

METHODS

The retrospective case-control study included 353 patients who underwent surgical treatment for complete rotator cuff tear using the suture-bridge technique. Patients who initially presented with retears and traumatic tears were excluded. In study participants, after the initial tear repair, rotator cuff retears were diagnosed by magnetic resonance imaging; Sugaya classification types IV and V were defined as re-tears. Age, gender, stump classification, tear size, Goutallier classification, presence of diabetes, and hyperlipidemia were used for ML parameters to predict the risk of retear. Using Python's Scikit-learn as an ML library, five different AI models (logistic regression, random forest, AdaBoost, CatBoost, LightGBM) were trained on the existing data, and the prediction models were applied to the test dataset. The performance of these ML models was measured by the area under the receiver operating characteristic curve. Additionally, key features affecting retear were evaluated.

RESULTS

The area under the receiver operating characteristic curve for logistic regression was 0.78, random forest 0.82, AdaBoost 0.78, CatBoost 0.83, and LightGBM 0.87, respectively for each model. LightGBM showed the highest score. The important factors for model prediction were age, stump classification, and tear size.

CONCLUSIONS

The ML classifier model predicted retears after ARCR with high accuracy, and the AI model showed that the most important characteristics affecting retears were age and imaging findings, including stump classification. This model may be able to predict postoperative rotator cuff retears based on clinical features.

Injuries to both anterolateral ligament and Kaplan fiber of the iliotibial band do not increase preoperative pivot-shift phenomenon in ACL injury

Background

To assess the incidence of anterolateral ligament (ALL) and Kaplan fiber of the iliotibial band (KF) injuries in patients with acute anterior cruciate ligament (ACL) injury on magnetic resonance imaging (MRI), and to investigate the association between these injuries and the magnitude of preoperative pivot-shift test.

Method

One-hundred and five patients with primary ACL injury were retrospectively reviewed. ALL injury and KF injury were assessed by preoperative MRI, and subjects were allocated into four groups: Group A, neither injury; Group B, only ALL injury; Group C, only KF injury; Group D, simultaneous ALL and KF injuries. Before ACL reconstruction, tibial acceleration during the pivot-shift test was measured by an electromagnetic measurement system, and manual grading was recorded according to the International Knee Documentation Committee (IKDC) guideline.

Results

In MRI, the ALL was identified in 104 patients (99.1%) and KF in 99 patients (94.3%). ALL and KF injuries were observed in 43 patients (43.9%) and 23 patients (23.5%), respectively. Patient distribution to each group was as follows; Group A: 43 patients (43.9%), Group B: 32 patients (32.7%), Group C: 12 patients (12.2%), Group D: 11 patients (11.2%). No significant differences were observed in tibial acceleration, and manual grading among the four groups.

Conclusion

Simultaneous injury to both ALL and KF was uncommon, and preoperative pivot-shift phenomenon did not increase even in those patients. The finding suggests that the role of ALL and KF in controlling anterolateral rotatory knee laxity may be less evident in the clinical setting compared to a biomechanical test setting.

Association Between Psychological Readiness to Return to Sports at 3 Months Postoperatively and Risk of Second ACL Injury

Background

Psychological readiness to return to sports (RTS) has been associated with second anterior cruciate ligament (ACL) injury. However, this relationship is controversial because covariates such as anatomic and knee function characteristics have not been adequately considered.

Purpose/Hypothesis

To investigate whether psychological readiness in the early postoperative period can predict the occurrence of a second ACL injury within 24 months after primary ACL reconstruction (ACLR) using propensity score analysis. It was hypothesized that patients with high ACL-RSI after injury (ACL-RSI) scores at 3 months postoperatively would have a second ACL injury within the projected postoperative period.

Study Design

Cohort study; Level of evidence, 3.

Methods

Included were 169 patients who underwent primary ACLR using hamstring tendon autografts between November 2017 and July 2021 and also underwent knee functional assessments at 3 months postoperatively. The ACL-RSI scale was used to assess psychological readiness for RTS. A second ACL injury was defined if ipsilateral or contralateral ACL injury was confirmed by examination within 24 months postoperatively. Based on a previous study showing that 65 was the highest cutoff value for the ACL-RSI score for RTS, we classified patients into 2 groups: those with high ACL-RSI scores (≥65; group H) and those with low ACL-RSI scores (<65; group L). We generated 1-to-1 matched pairs using propensity score analysis and used log-rank testing to compare the rate of second ACL injury between the 2 groups.

Results

More patients returned to any sports activities within 12 months in group H than in group L (90% vs 73%; P = .03). A second ACL injury within 24 months postoperatively was identified in 7% of patients (13/169). The rate of second ACL injury was significantly higher in group H than in group L (17.6% vs 3.4%; P = .001). In 43 matched pairs extracted using propensity scoring, the rate of second ACL injury was also higher in group H than in group L (18.6% vs 4.7%; P = .04).

Conclusion

Patients with a higher ACL-RSI score at 3 months exhibited a significantly higher incidence of second ACL injury within 24 months after primary ACLR.

Knee Osteotomy Decreases Joint Inflammation Based on Synovial Histology and Synovial Fluid Analysis

PURPOSE

To examine the biological changes in the joints of patients with knee osteoarthritis (OA) before and after around-knee osteotomy (AKO), focusing on synovial fluid (SF) and synovial pathological changes.

METHODS

Patients who underwent AKO for medial compartment knee OA between 2019 and 2021 were examined. SF and synovium were obtained at the time of AKO and plate removal after bone union (mean, 16.8 months [range: 11-38 months] postoperatively). SF volume and interleukin (IL)-6 concentrations in SF were assayed using enzyme-linked immunosorbent assay. Synovitis was assessed histologically using a semiquantitative scoring system. Macrophage infiltration was assessed by immunohistochemistry using a semiquantitative score for F4/80 expression. The M1/M2 ratio was calculated using percentage of cells positive for CD80 and CD163. The expression of proinflammatory cytokines was assessed by the percentage of IL-1β- and IL-6-positive cells. The number of vascular endothelial growth factor-positive luminal structures was counted to assess angiogenesis. The change in each parameter was compared before and after AKO using the Wilcoxon matched-pairs signed-rank test.

RESULTS

Twenty-four knees of 21 patients were included. SF volume and IL-6 concentration significantly decreased postoperatively (12.6 ± 2.1 mL vs 4.2 ± 0.6 mL; P < .0001 and 50.5 ± 8.6 pg/mL vs 20.7 ± 3.8 pg/mL; P = .0001, respectively). A significant reduction in synovitis score (P = .0001), macrophage infiltration (P < .0003), M1/M2 ratio (P < .0007), angiogenesis (P < .0001), and the percentage of IL-1β- and IL-6-positive cells in the intima (P < .008 and P < .002, respectively) was found after AKO.

CONCLUSIONS

SF volume and IL-6 concentrations in the SF decreased and inflammatory synovium pathology improved after AKO. In addition to biomechanical changes, the biological environment of the joint can be improved after AKO.

LEVEL OF EVIDENCE

Level IV, retrospective therapeutic case series.

The severity of preoperative varus deformity affects the feasibility of correcting lower limb alignment with medial unicompartmental knee arthroplasty

BACKGROUND

The relationship between the severity of preoperative varus deformity and the amount of its correction in unicompartmental knee arthroplasty (UKA) as well as the thickness of the insert has not been well known.

METHODS

One hundred and three patients who underwent medial fixed-bearing UKA with the use of the spacer block method were assessed. After the component gap in extension was measured using a UKA tensor, the pre-osteotomy gap was calculated from the thickness of the bone cuts. The relationship between the preoperative hip-knee-ankle (HKA) angle as well as the pre-osteotomy gap and the amount of change in HKA angle were analysed. Also, preoperative HKA angle and the thickness of the bone cuts were compared among groups by the insert thickness.

RESULTS

The mean preoperative HKA angle was 7.7 ± 3.1° varus. Patients with more varus deformity and those with a wider pre-osteotomy gap showed a more valgus change in HKA angle. As for the thickness of the insert, the preoperative HKA angle of the patients with the thinnest insert was significantly smaller (less varus) than that of those with the thicker insert while no statistically significant difference was found among the insert groups regarding the amount of the bone cuts.

CONCLUSIONS

The severity of the preoperative varus deformity as well as the intraoperative pre-osteotomy gap related to the amount of change in HKA angle. As thick inserts tended to be used in severe varus knees, the tibial bone cut can be reduced in such cases.

Clinical outcomes of arthroscopic lateral ligament repair using a knotless anchor for chronic lateral ankle instability

Background/objective

Arthroscopic lateral ligament repair (ALLR) for chronic lateral ankle instability (CLAI) has been improving with technical innovations. However, there is a lack of information regarding mid- and/or long-term clinical outcomes after the introduction of ALLR. This study aimed to report mid-term clinical outcomes of ALLR with a knotless anchor.

Methods

Thirty-two patients (11 men and 21 women; mean age, 28 ± 14 years) who underwent ALLR with a knotless anchor from December 2015 to October 2020 were included. The mean follow-up period was 31 ± 11 months. The Japanese Society for Surgery of the Foot (JSSF) ankle-hindfoot scale and the Self-Administered Foot Evaluation Questionnaire (SAFE-Q) were used for clinical evaluation preoperatively and at the 2-year follow-up. Surgical complications, particularly knot irritation, were also examined.

Results

The JSSF scale scores were significantly improved, from 71.3 ± 13.1 preoperatively to 96.6 ± 5.1 postoperatively (P < 0.05), and the SAFE-Q showed similar improvement in all subscales (P < 0.05). One case had a complication of persistent pain around the lateral portal (3.1%).

Conclusion

ALLR using a knotless anchor provided satisfactory clinical outcomes over 2 years, and no major complications, such as knot irritation, were observed.

Case series

Level of Evidence, 4.

Decreased posterior tibial slope is a risk factor for primary posterior cruciate ligament rupture and posterior cruciate ligament reconstruction failure: A systematic review

PURPOSE

To determine bony knee morphological factors associated with primary posterior cruciate ligament (PCL) rupture or PCL graft failure after PCL reconstruction.

METHODS

Three databases, namely MEDLINE, PubMed and EMBASE, were searched on 30th May 2023. The authors adhered to the PRISMA and R-AMSTAR guidelines as well as the Cochrane Handbook for Systematic Reviews of Interventions. Data such as receiver operating characteristic curve parameters, as well as p-values for comparisons of values between patients with PCL pathology and control patients, were recorded.

RESULTS

Nine studies comprising 1054 patients were included. Four studies reported that patients with PCL injury had flatter medial posterior tibial slopes (MTS) than controls, with mean values of 4.3 (range: 3.0-7.0) and 6.5 (range: 5.0-9.2) degrees, respectively. Two studies reported an MTS cutoff value ranging below 3.90-3.93° being a significant risk factor for primary PCL rupture or PCL graft failure. Two studies reported that shallow medial tibial depths were associated with primary PCL rupture, with mean values of 2.1 (range: 2.0-2.2) and 2.6 (range: 2.4-2.7) mm in PCL injury and control groups, respectively. Stenotic intercondylar notches and femoral condylar width were not consistently associated with PCL injuries.

CONCLUSION

Decreased MTS is associated with primary PCL rupture and graft failure after PCL reconstruction with values below 3.93° being considered as a significant risk factor. Less common risk factors include shallow medial tibial depth, while femoral condylar width and parameters with regards to the intercondylar notch, such as notch width, notch width index and intercondylar notch volume, demonstrated conflicting associations with primary or secondary PCL injuries.

LEVEL OF EVIDENCE

Level III.

Intra-articular site-specific distribution of advanced glycation end products in the shoulder of patients with diabetes mellitus having rotator cuff tears

BACKGROUND

Advanced glycation end products (AGEs) are compounds formed due to aging and diabetes mellitus (DM). They activate NADPH oxidase (NOX) by binding to their receptors, thereby increasing the production of reactive oxygen species (ROS), which cause oxidative stress. In this study, we investigated the effects of AGEs on the tissues of the shoulder joint (such as rotator cuff synovium, and capsule) in patients with DM having rotator cuff tears.

METHODS

This study included eight patients with DM who underwent surgical treatment for rotator cuff tears with contracture. The rotator cuff, synovium, and joint capsule were harvested at the time of surgery and evaluated by hematoxylin-eosin staining. Furthermore, immunostaining was used for evaluating AGEs and receptor for AGEs (RAGE), cell activity, ROS, and apoptosis. Quantitative real-time polymerase chain reaction (qPCR) was employed for the cellular evaluation of NOX, interleukins, RAGE, and collagen.

RESULTS

The AGEs and RAGE staining as well as the ratio of ROS and apoptosis were in the following order: rotator cuff > joint capsule > synovium. In contrast, the cellular activity was significantly higher in the synovium than in the other regions. The type I collagen expression (as shown by qPCR) as well as the RAGE and NOX expressions were as follows: rotator cuff > joint capsule > synovium. Conversely, the expression of inflammatory cytokines (i.e., IL-6 and IL-1β) was higher in the synovium than in the other regions.

CONCLUSIONS

Our study is among the first to evaluate the effects of AGEs on each tissue of the shoulder joint in patients with DM having rotator cuff tears and contractures. The accumulation of AGEs in each tissue of the shoulder joint could reveal the locations affected by DM, which can lead to a better understanding of the pathophysiology of DM-related shoulder diseases.

Contralateral hamstring autografts do not provide benefit compared to ipsilateral hamstring autografts in primary or revision anterior cruciate ligament reconstruction: a systematic review

PURPOSE

To evaluate the clinical outcomes of primary or revision ACL reconstruction (ACLR) after contralateral hamstring autografts versus ipsilateral hamstring autograft harvest.

METHODS

Three databases (MEDLINE, PubMed and EMBASE) were searched from inception to April 27th, 2023 for studies investigating contralateral hamstring autografts in primary or revision ACLR. The authors adhered to the PRISMA and R-AMSTAR guidelines as well as the Cochrane Handbook for Systematic Reviews of Interventions. Data on demographics, strength measures, patient-reported outcome measures (PROMs), and rates of positive Lachman test, positive pivot-shift test and graft rupture were extracted. PROMs included Lysholm, International Knee Documentation Committee (IKDC) and Tegner scores.

RESULTS

Nine studies comprising 371 patients were included in this review. In primary ACLR, there were no significant differences between contralateral and ipsilateral groups in isokinetic hamstring torque in the non-ACLR limb or isokinetic quadriceps torque in both limbs when tested at 60, 90, 120 or 180 degrees/second. Isokinetic hamstring torque in the non-ACLR limb was significantly weaker in the contralateral group at six months for primary ACLR; however, these deficits did not persist. There were no significant differences in postoperative median Tegner scores and Lysholm scores between contralateral and ipsilateral groups in primary ACLR. There were no significant differences in postoperative median Tegner, mean Lysholm and IKDC scores between groups in revision ACLR. There were no significant differences in positive Lachman, positive pivot-shift and rupture rates in primary ACLR between groups. Rates of positive Lachman and pivot-shift were slightly higher in the contralateral than ipsilateral group for revision ACLR.

CONCLUSION

Contralateral hamstring autografts results in comparable muscle strength to ipsilateral hamstring autografts, with the exception of weaker hamstring strengths in the early postoperative period. Patient-reported outcome measures were similar between the two groups across both primary and revision ACLR, with rates of instability and failure being similar between groups for primary ACLR. Contralateral hamstring grafts do not provide additional benefit when compared to ipsilateral options for either primary or revision ACLR, and should be used only in select circumstances including insufficient ipsilateral hamstring grafts or situations where quadriceps or patella autografts are not optimal.

LEVEL OF EVIDENCE

Level IV.

Though five-strand hamstring autografts demonstrate greater graft diameter, postoperative outcomes are equivocal to four-strand hamstring autograft preparations: a systematic review and meta-analysis of level I and II studies

PURPOSE

To compare graft dimensions, functional outcomes, and failure rates following anterior cruciate ligament reconstruction (ACLR) with either five-strand or four-strand hamstring autograft options.

METHODS

Three databases (MEDLINE, PubMed, and EMBASE) were searched from inception to 22 April 2023 for level I and II studies comparing five- and four-strand hamstring autografts in ACLR. The authors adhered to the PRISMA and R-AMSTAR guidelines as well as the Cochrane Handbook for Systematic Reviews of Interventions. Data on demographics, surgical details and rehabilitation, graft diameter, patient-reported outcome measures (PROMs), and rates of positive Lachman test, positive pivot shift test, and graft rupture were extracted. PROMs included Knee Osteoarthritis and Outcome Score (KOOS) subscales, Lysholm, and International Knee Documentation Committee (IKDC).

RESULTS

One randomized controlled trial (RCT) and four prospective cohort studies with 572 patients were included. Graft diameters were larger in the five-strand group with a mean difference of 0.93 mm (95% CI 0.61 to 1.25, p < 0.001, I2 = 66%). The five-strand group reported statistically higher KOOS ADL subscale and Lysholm scores with a mean difference of 4.85 (95% CI 0.14 to 9.56, p = 0.04, I2 = 19%) and 3.01 (95% CI 0.48 to 5.53, p = 0.02, I2 = 0%), respectively. There were no differences in KOOS symptoms, pain, quality of life, or sports subscales, or IKDC scores. There were no differences in rates of positive Lachman test, positive pivot shift test, or graft rupture with pooled odds ratios of 0.62 (95% CI 0.13 to 2.91, n.s., I2 = 80%), 0.94 (95% CI 0.51 to 1.75, n.s., I2 = 31%), and 2.13 (95% CI 0.38 to 12.06, n.s., I2 = 0%), respectively.

CONCLUSIONS

Although five-stranded hamstring autografts had significantly larger graft diameters compared to four-stranded grafts with a mean difference of 0.93 mm, similar graft rupture rates and clinical laxity assessments were identified following ACLR. While some PROMs were statistically superior in the five-stranded hamstring groups, the threshold for the minimal clinical important difference was not reached indicating similar clinical outcomes overall.

LEVEL OF EVIDENCE

Level II.

Partial debridement is the most commonly reported treatment option for mucoid degeneration of the anterior cruciate ligament: a systematic review

PURPOSE

To determine clinical outcomes and risks of various management strategies for mucoid degeneration of the anterior cruciate ligament (MD-ACL).

METHODS

Three databases MEDLINE, PubMed and EMBASE were searched from inception to January 29th, 2023 for literature outlining clinical outcomes for various management strategies of MD-ACL. The authors adhered to the PRISMA and R-AMSTAR guidelines as well as the Cochrane Handbook for Systematic Reviews of Interventions. Data on satisfaction scores, visual analogue scale (VAS) scores, Lysholm scores, International Knee Documentation Committee (IKDC) scores, Knee Osteoarthritis and Outcome Scores (KOOS), range of motion and Lachman test were recorded.

RESULTS

A total of 14 studies comprising 776 patients (782 knees) were included in this review. Partial debridement was reported in ten (71.4%) studies comprising 446 patients, showing significant improvements in VAS, Lysholm, IKDC scores and range of motion. Complete debridement was reported by two (14.2%) studies comprising 250 patients, and resulted in increases in Lysholm scores, KOOS, and range of motion. Reduction plasty was reported in two (14.2%) studies comprising 26 patients and showed improvements in VAS and Lysholm scores, and range of motion. Other methods of treatment included conservative management and ultrasound decompression. Complete debridement resulted in 10/23 (43%) patients with a positive Lachman test. This was followed by reduction plasty and partial debridement, with 5/26 (19.2%) and 45/340 (13.2%) patients respectively having positive Lachman or elevated knee arthrometer scores. Pivot shifting was only reported in studies on partial debridement and reduction plasty, with 14/93 (15.1%) and 1/21 (4.8%) patients have positive results, respectively.

CONCLUSION

The most commonly reported management strategy for MD-ACL is partial debridement with complete debridement, reduction plasty and conservative management as alternative options. Current operative management strategies place individuals at risk for ACL insufficiency. Information from this review can aid surgeons and clinicians in understanding what treatment options are best for this patient population, by understanding the reported clinical benefits and risks of each strategy.

LEVEL OF EVIDENCE

IV.

Technology-assisted anterior cruciate ligament reconstruction improves tunnel placement but leads to no change in clinical outcomes: a systematic review and meta-analysis

PURPOSE

To investigate the effect of technology-assisted Anterior Cruciate Ligament Reconstruction (ACLR) on post-operative clinical outcomes and tunnel placement compared to conventional arthroscopic ACLR.

METHODS

CENTRAL, MEDLINE, and Embase were searched from January 2000 to November 17, 2022. Articles were included if there was intraoperative use of computer-assisted navigation, robotics, diagnostic imaging, computer simulations, or 3D printing (3DP). Two reviewers searched, screened, and evaluated the included studies for data quality. Data were abstracted using descriptive statistics and pooled using relative risk ratios (RR) or mean differences (MD), both with 95% confidence intervals (CI), where appropriate.

RESULTS

Eleven studies were included with total 775 patients and majority male participants (70.7%). Ages ranged from 14 to 54 years (391 patients) and follow-up ranged from 12 to 60 months (775 patients). Subjective International Knee Documentation Committee (IKDC) scores increased in the technology-assisted surgery group (473 patients; P = 0.02; MD 1.97, 95% CI 0.27 to 3.66). There was no difference in objective IKDC scores (447 patients; RR 1.02, 95% CI 0.98 to 1.06), Lysholm scores (199 patients; MD 1.14, 95% CI - 1.03 to 3.30) or negative pivot-shift tests (278 patients; RR 1.07, 95% CI 0.97 to 1.18) between the two groups. When using technology-assisted surgery, 6 (351 patients) of 8 (451 patients) studies reported more accurate femoral tunnel placement and 6 (321 patients) of 10 (561 patients) studies reported more accurate tibial tunnel placement in at least one measure. One study (209 patients) demonstrated a significant increase in cost associated with use of computer-assisted navigation (mean 1158€) versus conventional surgery (mean 704€). Of the two studies using 3DP templates, production costs ranging from $10 to $42 USD were cited. There was no difference in adverse events between the two groups.

CONCLUSION

Clinical outcomes do not differ between technology-assisted surgery and conventional surgery. Computer-assisted navigation is more expensive and time consuming while 3DP is inexpensive and does not lead to greater operating times. ACLR tunnels can be more accurately located in radiologically ideal places by using technology, but anatomic placement is still undetermined because of variability and inaccuracy of the evaluation systems utilized.

LEVEL OF EVIDENCE

Level III.

Combining age, sex, body mass index, sport level, and preoperative quadriceps strength improves the predictive ability of quadriceps strength recovery after anterior cruciate ligament reconstruction

PURPOSE

This study compared the predictive ability of each independent predictor with that of a combination of predictors for quadriceps strength recovery one year after anterior cruciate ligament (ACL) reconstruction.

METHODS

Patients who underwent primary ACL reconstruction using hamstring autografts were enrolled. Quadriceps strength, hamstring strength, and anterior tibial translation were measured, and the limb symmetry index (LSI) of the quadriceps and the hamstrings was calculated preoperatively and one year after surgery. Patients were classified into two groups according to the LSI of the quadriceps strength at one year postoperatively (≥ 80% or < 80%). Multivariate logistic regression analysis identified the independent predictors of quadriceps strength recovery, and the cut-off value was calculated using the receiver operating characteristic curve. A model assessing predictive ability of the combination of independent predictors was created, and the area under the curve (AUC) for each independent predictor was calculated by using the receiver-operating characteristic curves and the DeLong method.

RESULTS

Of the 646 patients, 414 (64.1%) had an LSI of at least 80% for quadriceps strength one year after surgery, and 232 patients (35.9%) had an LSI of < 80%. Age, sex, body mass index (BMI), preinjury sport level, and LSI of preoperative quadriceps strength were independently associated with quadriceps strength recovery one year after ACL reconstruction. The cut-off values were age: 22.5 years; sex: female; BMI: 24.3 kg/m2; preinjury sport level: no sport; and LSI of preoperative quadriceps strength: 63.3%. The AUC of the model assessing the predictive ability of the combination of age, sex, BMI, preinjury sport level, and LSI of preoperative quadriceps strength was significantly higher (0.73) than that of similar factors of preoperative quadriceps strength (AUC: 0.63, 0.53, 0.56, 0.61, and 0.68, p < 0.01, respectively).

CONCLUSION

The combination of age, sex, BMI, preinjury sport level, and LSI of preoperative quadriceps strength had a superior predictive ability for quadriceps strength recovery at one year after ACL reconstruction than these predictors alone. Multiple factors, including patient characteristics and preoperative quadriceps strength, should be considered when planning rehabilitation programs to improve quadriceps strength recovery after ACL reconstruction.

LEVEL OF EVIDENCE

III.

Talar component subsidence correlates with periprosthetic osteolysis after total ankle arthroplasty

PURPOSE

This study aimed to investigate the relationship between periprosthetic osteolysis around the talar component and the amount of talar component subsidence after total ankle arthroplasty (TAA).

METHODS

This study included forty patients who underwent TAA with a mean follow-up of 67.5 ± 17.0 months. The patients were divided into two groups based on the amount of osteolysis around the talar component, as measured by computed tomography at the latest clinic visit: none to 2 mm (N group, n = 20) and greater than or equal to 2 mm (O group, n = 20). The average amount of talar component subsidence, clinical outcomes, and complications were compared between the two groups. In the O group, the correlation between osteolysis and talar component subsidence was evaluated.

RESULTS

The average talar component subsidence was significantly different between the N (0.22 ± 0.94 mm) and O groups (2.12 ± 2.28 mm). Five out of 20 ankles in the O group required revision surgery owing to talar component subsidence. The Japanese Society for Surgery of the Foot scores in the N and O groups were significantly different: 93.5 ± 7.7 and 85.3 ± 15.4, respectively. In the O group, we found that osteolysis tended to develop on the lateral side, and the amount of osteolysis was positively correlated with the talar component subsidence (r = 0.59, P = .007).

CONCLUSION

In the O group, a positive correlation between osteolysis and talar component subsidence was found, and five patients required revision surgery.

Current development in surgical techniques, graft selection and additional procedures for anterior cruciate ligament injury: a path towards anatomic restoration and improved clinical outcomes-a narrative review

Background and Objective

Anterior cruciate ligament (ACL) reconstruction has been widely used for ACL injury for a long time. However, residual rotational instability and osteoarthritic changes after ACL reconstruction have been identified as problems. Thus, anatomic reconstruction techniques, various types of grafts and additional procedures have been desired to improve the clinical outcomes and knee instability. Although clinical outcomes and knee stability are better than in the past, ipsilateral graft failures still occur in 4-17% and osteoarthritic changes are seen in about 20% of patients after ACL reconstruction. To remedy these problems, it is necessary to improve the understanding of various surgical techniques and grafts and to pursue further improvement of surgical techniques. Therefore, the objective of this review is to summarize the advantages and disadvantages of various surgical techniques and graft selection, and additional procedures for ACL injury.

Methods

A literature review was conducted on the surgical procedures for ACL injury. Recent trends in surgical techniques, graft selection, and additional procedures for ACL injury were described. We performed a literature search in PubMed for studies published from origin to May 8, 2023. Studies were required to be English-language articles.

Key Content and Findings

Although many reports indicate that double-bundle ACL reconstruction is comparable to anatomic single-bundle (SB) reconstruction, intraoperative complications such as tunnel coalition exist in double-bundle reconstruction, and the technique needs to be improved. ACL repair has shown good short-term results, but long-term results need to be examined in the future. Quadriceps tendon autograft is being used more frequently, but hamstrings tendon autograft and bone-patellar tendon-bone autograft also have good results. In addition, in higher-risk cases, lateral extra-articular tenodesis (LET) and anterolateral ligament (ALL) reconstruction can be performed with good results.

Conclusions

To further improve clinical outcomes, more anatomical reconstructions should be pursued. Autografts are better than allografts and synthetic grafts, but further study is needed to determine which graft is better. Additional procedures should be performed in highly unstable cases and in revision cases.

Clinical Characteristics and Surgical Outcomes of Metastatic Spine Tumors in the Very Elderly: A Prospective Cohort Study in a Super-Aged Society

The number of advanced-age patients with spinal metastases is rising. This study was performed to clarify the characteristics and surgical outcomes of spinal metastases in advanced-age patients. We prospectively analyzed 216 patients with spinal metastases from 2015 to 2020 and divided them into three age groups: <70 years (n = 119), 70-79 years (n = 73), and ≥80 years (n = 24). Although there were no significant intergroup differences in preoperative characteristics and surgery-related factors except for age, patients aged ≥80 years tended to have a worse performance status (PS), Barthel index, and EuroQol-5 dimension (EQ-5D) before and after surgery than the other two groups. Although the median PS, mean Barthel index and mean EQ-5D greatly improved postoperatively in each group, the median PS and mean Barthel index at 6 months and the mean EQ-5D at 1 month postoperatively were significantly poorer in the ≥80-year group than the 70-79-year group. The rates of postoperative complications and re-deterioration of the EQ-5D were significantly higher in the oldest group than in the other two groups. Although surgery for spinal metastases improved the PS, Barthel index, and EQ-5D regardless of age, clinicians should be aware of the poorer outcomes and higher complication rates in advanced-age patients.

Rehabilitation after Hip Fracture Surgery Improves Physical and Cognitive Function in Patients with or Without Sarcopenia

Introduction

Sarcopenia is a prevalent risk factor for falls and fractures, and it affects the physical function and mortality of older people. The present study was performed to assess the prevalence of sarcopenia in patients who underwent rehabilitation after hip fracture surgery and to examine the association of sarcopenia with physical and cognitive function outcomes.

Methods

This case-control study involved 132 patients who were admitted to a convalescent rehabilitation ward at a single hospital after surgical treatment of hip fractures from April 2018 to March 2020. The skeletal muscle mass index was examined using whole-body dual-energy X-ray absorptiometry. The Asian Working Group for Sarcopenia 2019 diagnostic criteria were applied on admission. We compared the walking speed, Mini-Mental State Examination (MMSE) score, and Functional Independence Measure (FIM) score between the sarcopenia group and non-sarcopenia group on admission and on discharge.

Results

The prevalence of sarcopenia was 59.8%. In the non-sarcopenia group, the walking speed, MMSE score, FIM total score, FIM motor score, and FIM cognitive score were significantly lower on admission than those on discharge (P < .05). In the sarcopenia group, the walking speed, MMSE score, FIM total score, and FIM motor score were significantly lower on admission than those on discharge (P < .05); there was no significant difference in the FIM cognitive score between admission and discharge. On both admission and discharge, the MMSE score, FIM total score, FIM motor score, and FIM cognitive score were significantly better in the non-sarcopenia group than those in the sarcopenia group.

Conclusions

After postoperative rehabilitation of hip fractures in patients with and without sarcopenia, physical and cognitive function outcomes on discharge were significantly better than those on admission. Patients with sarcopenia had significantly worse physical and cognitive function outcomes than patients without sarcopenia both on admission and on discharge.

Outcomes of palliative surgery for bone metastasis of metastatic renal cell carcinoma in the era of targeted therapy

INTRODUCTION

The introduction of tyrosine kinase inhibitors has revolutionized treatment strategies for metastatic renal cell carcinoma (RCC) and has improved survival rates. The number of patients with bone metastases from RCC requiring surgery will increase as survival rates improve. However, there is insufficient evidence to standardize the treatment of bone metastases after the introduction of targeted therapy for metastatic RCC. We aimed to determine the outcomes of palliative surgical treatment of bone metastases in the extremities of patients with metastatic RCC.

MATERIALS AND METHODS

We retrospectively reviewed 26 lesions from 17 patients who underwent surgery for extremity and acetabular bone metastases and were treated with targeted therapies for advanced RCC between 2008 and 2020. The median follow-up duration was 19 months (range, 4-76). We assessed the patients' activities of daily living, quality of life, and pain and analyzed their postoperative values relative to preoperative values. Postoperative overall survival (OS), local progression-free survival (LPFS), and the factors affecting them were evaluated using the Kaplan-Meier method and log-rank test.

RESULTS

The 5-year OS and LPFS rates were 39.5% and 65.6%, respectively. The factors affecting OS were sex, Katagiri score, visceral metastases, and preoperative targeted therapy, while the factors affecting LPFS were pathologic fractures and surgical technique.

CONCLUSION

In this study, the postoperative outcomes of palliative surgery for bone metastases from metastatic RCC were good. We suggest that systemic treatment should be prioritized over local control for advanced bone metastasis in RCC and surgery before pathological fracture should be performed for local control.

Elicitation of Inhibitory Effects for AGE-Induced Oxidative Stress in Rotator Cuff-Derived Cells by Apocynin

Advanced glycation end-products (AGEs) play a critical supportive role during musculoskeletal disorders via glycosylation and oxidative stress. Though apocynin, identified as a potent and selective inhibitor of NADPH oxidase, has been reported to be involved in pathogen-induced reactive oxygen species (ROS), its role in age-related rotator cuff degeneration has not been well clarified. Therefore, this study aims to evaluate the in vitro effects of apocynin on human rotator cuff-derived cells. Twelve patients with rotator cuff tears (RCTs) participated in the study. Supraspinatus tendons from patients with RCTs were collected and cultured. After the preparation of RC-derived cells, they were divided into four groups (control group, control + apocynin group, AGEs group, AGEs + apocynin group), and gene marker expression, cell viability, and intracellular ROS production were evaluated. The gene expression of NOX, IL-6, and the receptor for AGEs (RAGE) was significantly decreased by apocynin. We also examined the effect of apocynin in vitro. The results showed that ROS induction and increasing apoptotic cells after treatment of AGEs were significantly decreased, and cell viability increased considerably. These results suggest that apocynin can effectively reduce AGE-induced oxidative stress by inhibiting NOX activation. Thus, apocynin is a potential prodrug in preventing degenerative changes of the rotor cuff.

Patients with discoid menisci have similar clinical outcomes to those without discoid menisci when undergoing surgical intervention: a systematic review

PURPOSE

To compare post-operative clinical outcomes of discoid meniscus tear procedures such as saucerization with or without repair with those of non-discoid meniscus tears such as meniscectomy or repair in skeletally mature patients with no concomitant injuries.

METHODS

Three databases MEDLINE, PubMed and EMBASE were searched from inception to July 3rd, 2022 for literature describing patient-reported outcome measures after meniscus surgery in discoid or non-discoid meniscus tears. The authors adhered to the PRISMA and R-AMSTAR guidelines as well as the Cochrane Handbook for Systematic Reviews of Interventions. Clinical outcome data on Lysholm, Tegner, International Knee Documentation Committee (IKDC), revision rates, and complications were recorded, with MINORS and Detsky scores used for quality assessment.

RESULTS

A total of 38 studies comprising 2213 patients were included with a mean age of 38.6 years (range: 9.0-64.4). The mean follow-up time was 54.1 months (range: 1-234) and the average percentage of female participants was 46.8% (range: 9.5-95.5). The mean change between pre-operative and post-operative Lysholm scores ranged from 21.0-39.0, 7.4-24.1, and 24.2-48.4 in the discoid, non-discoid meniscectomy, and non-discoid repair groups, respectively. The mean change in Tegner scores ranged from 0.0 to 2.3, 1.3, and 0.4-1.3 in the discoid, non-discoid meniscectomy, and non-discoid repair groups, respectively. Pre-operative IKDC scores were not reported, however mean post-operative IKDC scores ranged from 77.4 to 96.0, 46.9 to 85.7, and 63.1 to 94.0 in discoid, non-discoid meniscectomy, and non-discoid repair groups, respectively. Revision rates for discoid procedures, non-discoid meniscectomies, and non-discoid meniscus repairs ranged from 3.2 to 44.0%, 8.3 to 56.0%, and 5.9 to 28.0%, respectively. The most common reasons for revision were acute trauma and persistent pain.

CONCLUSION

Discoid saucerization procedures with or without repair leads to similar Lysholm scores as non-discoid repair procedures, and similar IKDC scores and revision rates compared to non-discoid meniscectomy or repair procedures. Patients undergoing discoid procedures appeared to have slightly higher Tegner activity scores compared to patients undergoing non-discoid procedures; however this is to be considered in the context of a younger population of patients undergoing discoid procedures than non-discoid procedures. This information can help guide surgeons in the decision-making process when treating patients with discoid menisci, and should guide further investigations on this topic.

LEVEL OF EVIDENCE

IV.

Fibrin clot and Leukocyte-rich platelet-rich fibrin show similar release kinetics and amount of growth factors: a pilot study

BACKGROUND

In knee arthroscopic surgery, fibrin clot (FC) and leukocyte-rich platelet-rich fibrin (L-PRF) may be used in augmentation for meniscal repair. Studies have investigated growth factors released from FC and L-PRF; however, it is difficult to compare FC and L-PRF between different studies. Direct comparison of growth factors that may support meniscal healing released from FC and L-PRF may be beneficial in deciding whether to use FC or L-PRF. If no significant difference is seen, the surgeon may decide to use FC which is easier to prepare compared to L-PRF. The purpose of this pilot study is to investigate the release amount and pattern of basic fibroblast growth factor (bFGF), platelet-derived growth factor AB (PDGF-AB), transforming growth factor β1 (TGF-β1), vascular endothelial growth factor (VEGF), and stromal cell-derived factor 1 (SDF-1) from FC and L-PRF.

METHOD

Twenty milliliters (ml) of whole blood was collected from each of the four volunteers. Ten milliliters of whole blood was allocated for preparation of FC and 10 ml for L-PRF. FC and L-PRF were separately placed in 5 ml of culture media. Five milliliters of the culture media was sampled and refilled at 15 min, 1 day, 3 days, 1 week and 2 weeks. The collected culture was used to quantify bFGF, PDGF-AB, TGF-β1, VEGF, and SDF-1 release by Enzyme-linked immune-sorbent assay (ELISA). Mann-Whitney U test was performed to assess significance of differences in amount of each growth factor released between FC and L-PRF. Significance was accepted at P value less than 0.05.

RESULTS

At two weeks, the cumulative release of TGF-β1 was the highest among all the growth factors in both FC and L-PRF (FC:19,738.21 pg/ml, L-PRF: 16,229.79 pg/ml). PDGF-AB (FC: 2328 pg/ml, L-PRF 1513.57 pg/ml) had the second largest amount, followed by VEGF (FC: 702.06 pg/ml, L-PRF 595.99 pg/ml) and bFGF (FC: 23.48 pg/ml, L-PRF 18.2 pg/ml), which order was also common in both FC and L-PRF. No significant difference in final release amount and pattern was seen between FC and L-PRF.

CONCLUSION

The current pilot study showed that cumulative release amount and release pattern of PDGF-AB, VEGF, TGF-β1, and bFGF did not significantly differ between FC and L-PRF during the two weeks of observation.

Tibial tubercle to trochlear groove distance versus tibial tubercle to posterior cruciate ligament distance for predicting patellar instability: a systematic review

PURPOSE

To determine the reliability and diagnostic accuracy of tibial tubercle-trochlear groove (TT-TG) distance versus tibial tubercle-posterior cruciate ligament (TT-PCL) distance, and to determine cutoff values of these measurements for pathological diagnosis in the context of patellar instability.

METHODS

Three databases MEDLINE, PubMed and EMBASE were searched from inception to October 5, 2022 for literature outlining comparisons between TT-TG and TT-PCL in patellar instability patients. The authors adhered to the PRISMA and R-AMSTAR guidelines as well as the Cochrane Handbook for Systematic Reviews of Interventions. Data on inter-rater and intra-rater reliability, receiver-operating characteristic (ROC) curve parameters such as area under the curve (AUC), sensitivity and specificity, as well as odds ratios, cutoff values for pathological diagnosis and correlations between TT-TG and TT-PCL were recorded. The MINORS score was used for all studies in order to perform a quality assessment of included studies.

RESULTS

A total of 23 studies comprising 2839 patients (2922 knees) were included in this review. Inter-rater reliability ranged from 0.71 to 0.98 and 0.55 to 0.99 for TT-TG and TT-PCL, respectively. Intra-rater reliability ranged from 0.74 to 0.99 and 0.88 to 0.98 for TT-TG and TT-PCL, respectively. AUC measuring diagnostic accuracy of patellar instability for TT-TG ranged from 0.80 to 0.84 and 0.58 to 0.76 for TT-PCL. Five studies found TT-TG to have more discriminatory power than TT-PCL at distinguishing patients with patellar instability from patients who do not. Sensitivity and specificity ranged from 21 to 85% and 62 to 100%, respectively, for TT-TG. Sensitivity and specificity ranged from 30 to 76% and 46 to 86%, respectively, for TT-PCL. Odds ratio values ranged from 1.06 to 14.02 for TT-TG and 0.98 to 6.47 for TT-PCL. Proposed cutoff TT-TG and TT-PCL values for predicting patellar instability ranged from 15.0 to 21.4 mm and 19.8 to 28.0 mm, respectively. Eight studies reported significant positive correlations between TT-TG and TT-PCL.

CONCLUSION

TT-TG resulted in overall similar reliability, sensitivity and specificity as TT-PCL; however, TT-TG has better diagnostic accuracy than TT-PCL in the context of patellar instability as per AUC and odds ratio values.

LEVEL OF EVIDENCE

Level IV.

Clinical Outcomes After Anterior Cruciate Ligament Reconstruction in Patients With a Concomitant Segond Fracture: A Systematic Review

BACKGROUND

The Segond fracture can be observed in patients with an anterior cruciate ligament (ACL) tear. It is unclear whether the Segond fracture affects clinical outcomes after ACL reconstruction.

PURPOSE

To investigate whether the presence of a concomitant Segond fracture affects clinical outcomes after ACL reconstruction and to compare clinical outcomes when a Segond fracture is repaired surgically or left unrepaired.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

Three databases (PubMed, Embase, Cochrane Library) were searched in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines on July 27, 2020. Relevant studies regarding ACL injury with concomitant Segond fracture treated by primary ACL reconstruction were screened in duplicate. Data regarding patient characteristics and clinical outcomes were extracted. Descriptive data are presented, and a random-effects model was used to pool amenable data.

RESULTS

A total of 5 studies examining 2418 patients (987 female; 40.8%), mean age 25.4 years, were included in this study. There were 304 patients with a Segond fracture (mean age, 28.1 years; 35.9% female) and 2114 patients without a Segond fracture (mean age, 25.1 years; 41.5% female). Four studies directly compared outcomes between patients with an unrepaired Segond fracture and no Segond fracture. One study reported 12 patients who underwent ACL reconstruction and repair of a Segond fracture. Among 4 studies, 11 of 292 (3.8%) graft failures/revision surgeries were reported in the groups that had Segond fracture, whereas 145 of 2114 (6.9%) graft failures/revision surgeries were reported in groups that did not have Segond fracture. No significant difference was observed in the risk of graft failure between the 2 groups, with a pooled risk ratio of 0.59 (95% CI, 0.32-1.07; P = .08; I2 = 0%). No clinically significant differences were observed with regard to International Knee Document Committee score, Lysholm score, Tegner activity scale, and postoperative knee laxity between the group with Segond fracture and those without.

CONCLUSION

An unrepaired Segond fracture does not appear to have any significant negative effect on postoperative stability or risk of graft failure or revision surgery after ACL reconstruction. Future prospective studies may be warranted to confirm the finding that patients with combined ACL injury and Segond fracture may have outcomes comparable with those of ACL-injured patients without a Segond fracture when isolated ACL reconstruction is performed.

Risk factors of residual pivot-shift after anatomic double-bundle anterior cruciate ligament reconstruction

INTRODUCTION

Although anterior cruciate ligament reconstruction (ACLR) is considered a successful procedure, residual pivot-shift after surgery remains to be solved. The purpose of this study was to comprehensively evaluate the risk factors of residual pivot-shift after anatomic double-bundle (DB) ACLR.

MATERIALS AND METHODS

A total of 164 patients who underwent primary anatomic DB-ACLR between January 2014 and December 2019 and screw removal after the index ACLR in our hospital were included in this retrospective case-control study. The manual pivot-shift test was performed under general anesthesia during screw removal surgery, and patients with grade 1 or higher pivot-shift were classified as the positive pivot-shift group, and those with grade 0 were defined as the negative pivot-shift group. Univariate and logistic regression analyses were performed to identify the factors associated with postoperative residual pivot-shift. Assessment included sex, age, time to surgery, preoperative Tegner activity scale, preoperative pivot-shift grade, preoperative anterior tibial translation by the KT-2000 arthrometer measurement, meniscus injury and its surgical procedure, knee hyperextension, cartilage damage, Segond fracture, medial and lateral posterior tibial slope, lateral-medial slope asymmetry, participation in pivoting sport/activity at the time of injury, and return to sports at postoperative one year line.

RESULTS

Postoperative positive pivot-shift was observed in 14 (8.5%) of 164 patients. The KT-2000 measurement at 1-year postoperatively was significantly higher in the residual pivot-shift-positive group than in the negative group (P < 0.05). Logistic regression analysis revealed that age of patients < 20 years [P < 0.05, odds ratio (OR): 6.1)], preoperative pivot-shift grade (P < 0.05, OR: 4.4), and hyperextended knee (P < 0.05, OR: 11.8) were risk factors of postoperative pivot-shift. There were no statistically significant differences between other variables.

CONCLUSIONS

Patients < 20 years of age, with high-grade preoperative pivot-shift, or hyperextended knees had a higher risk of residual postoperative pivot-shift.

Degree of Accuracy With Which Deep Learning for Ultrasound Images Identifies Osteochondritis Dissecans of the Humeral Capitellum

BACKGROUND

Medical screening using ultrasonography (US) has been performed on young baseball players for early detection of osteochondritis dissecans (OCD) of the humeral capitellum. Deep learning (DL) and artificial intelligence (AI) techniques are widely adopted in the medical imaging research field.

PURPOSE/HYPOTHESIS

The purpose of this study was to calculate the diagnostic accuracy using DL for US images of OCD. We hypothesized that using DL for US imaging would improve the prediction accuracy of OCD.

STUDY DESIGN

Cohort study (Diagnosis); Level of evidence, 2.

METHODS

A total of 40 elbows (mean age of patients, 12.1 years) that were suspected of having OCD at a medical checkup and later confirmed by radiographs and magnetic resonance imaging were included in the study. The affected elbows were used as the OCD group and the contralateral elbows as the control group. From US videos, 100 images per elbow were captured from different angles, and 4000 images of the elbows were prepared for both groups. Of these, 80% were randomly selected by DL models and used as training data; the remaining were used as test data. Transfer learning was conducted using 3 pretrained DL models. The confusion matrix and the area under the receiver operating characteristic curve (AUC) were used to evaluate the model, and the visualization of the areas deemed important by the DL models was also performed. Furthermore, OCD regions were detected using an automatic image recognition model based on DL.

RESULTS

Classification of the OCD image by the DL model was performed; the best accuracy score was 0.87; the recall was 1.00. AUC was high for all DL models. Visualization of important features showed that AI predicted the presence of OCD by focusing on the irregularity or discontinuity of the surface of subchondral bone. In the detection of OCD task, the mean average precision was 0.83.

CONCLUSION

The DL on US images identified OCD with high accuracy. The important features detected by the DL models correspond to the areas used by clinicians in screening the US images. The OCD was also detected with high accuracy using the object detection model. The AI model may be used in medical screening for OCD.

Anatomical double-bundle anterior cruciate ligament reconstruction moderately improved tegner scores over the long-term: a systematic review and meta-analysis of randomized controlled trials

PURPOSE

To assess the effects of anatomical double-bundle (DB) versus single-bundle (SB) for anterior cruciate ligament (ACL) reconstruction in skeletally mature patients with ACL injuries.

METHODS

MEDLINE, EMBASE, and CENTRAL were searched from inception to February 7, 2022 were screened for randomized controlled trials. The Anatomic Anterior Cruciate Ligament Reconstruction Checklist was used to categorize studies as anatomic. A random-effects meta-analysis was conducted, with pooled results being summarized using mean difference (MD). Risk of Bias (RoB) was assessed using the RoB 2.0 tool. Certainty of evidence was rated using GRADE.

RESULTS

A search of 1371 unique articles yielded eight eligible trials, representing 735 patients (360 DB, 375 SB) with mean (SD) age of 28.5 (2.86) years and follow-up of 52.1 (36.2) months. Most trials had moderate to low RoB. Overall, DB was not significantly better than SB on Lysholm scores (MD = 0.52, 95% CI, - 1.80-2.85, p = 0.66; moderate certainty) or subjective International Knee Documentation Committee (IKDC) scores (MD = - 0.40, 95% CI, - 4.35-3.55, p = 0.84; moderate certainty). Tegner scores were significantly higher in SB than DB in the intermediate term (MD = - 0.72, 95% CI, - 1.10 to - 0.34, p = 0.0002; high certainty), while significantly higher in DB relative to SB in the long-term (MD = 0.52, 95% CI, 0.02-1.03, p = 0.04; high certainty).

CONCLUSION

DB ACL reconstruction significantly improves Tegner scores relative to SB ACL reconstruction over the long-term (t ≥ 5 years). Intermediate term Tegner scores favour SB reconstruction. In both durations, there was no clinically significant difference based on the pre-specified minimal clinically important difference of 1.0 point. There were also no significant differences in IKDC or Lysholm scores. Surgeons should consider anatomical DB ACL reconstruction as a result of long-term improvement in patient-reported outcomes.

LEVEL OF EVIDENCE

I.

Less than 1% risk of donor-site quadriceps tendon rupture post-ACL reconstruction with quadriceps tendon autograft: a systematic review

PURPOSE

The purpose of this study is to develop a comprehensive complications profile for quadriceps tendon-autograft anterior cruciate ligament reconstruction (QT ACL-R).

METHODS

A traditional and grey literature search was conducted in accordance with PRISMA and R-AMSTAR guidelines. PubMed, EMBASE, MEDLINE, CINAHL, Cochrane, Web of Science, and many grey literature sources were searched from inception to May 29, 2022. All studies were searched and screened in duplicate with included studies being of all levels of evidence, reporting complications, and with patients of all ages undergoing primary ACL reconstruction with quadriceps tendon autograft in the last 15 years. Studies were excluded if they had cadaveric or animal subjects or were reviews. Risk of bias assessment was conducted using MINORS criteria for non-randomised studies and Cochrane's RoB 2.0 for randomised studies. Data were summarised with weighted event rates generated under a random-effects model.

RESULTS

A total of 55 studies (5315 reconstructions) were included: 32 used quadriceps tendon with bone block (B-QT), 19 used all-soft tissue quadriceps tendon (S-QT), and four did not report the QT graft subtype used. Included patients had an age range of 6.2-58 years and an average reported follow-up time of 28.1 months (range, 6-90 months) for non-randomised studies and 34.3 months (range, 0.233-120 months) for randomised studies. Pooled incidence rates for clinically relevant major complications included contralateral ACL injury at 6.0%, postoperative meniscal issues at 5.4%, cyclops lesions at 4.8%, graft failure at 4.1%, patellar fracture at 2.2%, hardware removal at 1.7%, infection at 1.5%, and donor-site quadriceps tendon rupture at 0.7%. Pooled incidence rates for clinically relevant minor complications included anterior knee pain at 9.7%, kneeling pain at 9.5%, sensation deficits at 4.4%, loss of extension at 4.2%, donor-site tendinopathy at 3.9%, cosmetic issues at 1.8%, and hematoma at 1.5%.

CONCLUSIONS

QT ACL-R resembles other graft types in its rates and types of postoperative complications. In this exploratory systematic review, no complications of QT ACL-R were found to be disproportionately represented in the literature. This graft type should remain an option with comparable complication rates to other graft choices.

LEVEL OF EVIDENCE

Level IV.

REGISTRATION

This study was preregistered under PROSPERO with preregistration code CRD42022302078.

Development and Analysis of Mouse Medial Meniscus Posterior Root Tear Model

Medial meniscus posterior root tears (MMPRT) are often associated with osteoarthritis (OA) progression and subchondral bone insufficiency fractures. This study aimed to develop the first MMPRT mouse model. The MMPRT model was created by sectioning the medial meniscus posterior root of 12-week-old CL57BL/6J male mice under stereomicroscopic observation. The sham operation and the destabilization of the medial meniscus (DMM) model groups were also created. OA progression and subchondral bone changes were evaluated histologically using the Osteoarthritis Research Society International (OARSI) subchondral bone scoring system at 2, 4, 8, and 12 weeks after surgery. Microcomputed tomography (µCT) was performed to evaluate the presence of insufficient fractures. OA progression and medial meniscus extrusion were observed in the MMPRT and DMM models 12 weeks after surgery. OA progressed in both models during the time course, without a significant difference in the OARSI score between the two groups. The subchondral bone score was significantly higher at 12 weeks than at 2 and 4 weeks in the MMPRT group, while no significant difference was found between the two groups. In the µCT analysis, destruction of the medial tibial plateau was observed in 4/40 knees, while none were observed in the DMM group. Of the four knees, destruction of the medial femoral condyle was also observed in three knees. Characteristic pathological changes were observed in the mouse MMPRT model. The mouse MMPRT model may be useful for investigating pathological changes after MMPRT.

Short-Term Clinical Outcomes Following Total Ankle Arthroplasty Without Concomitant Osteotomy in Ankles with Severe Preoperative Varus Deformity: Comparison to Ankles with Preoperative Neutral Alignment

BACKGROUND

It remains controversial whether satisfactory outcomes can be obtained following total ankle arthroplasty (TAA) without osteotomy in patients with severe varus ankle deformities. This study aimed to examine outcomes following TAA without concomitant osteotomies in patients with severe varus ankle alignment by comparing them with those in patients with neutral alignment.

METHODS

Fifty-one patients (53 ankles; mean age, 71.4 ± 5.6 years) who underwent TAA using the TNK ankle prosthesis were examined (mean follow-up, 36.8 ± 17.8 months). Patients were allocated into groups according to the preoperative talar tilt (TT) angle: the neutral group (preoperative TT angle <10°; n = 37) and the varus group (preoperative TT angle ≥10°; n = 16). Outcome measures, including the Japanese Society for Surgery of the Foot scale, Self-Administered Foot Evaluation Questionnaire, ankle range of motion, and radiographic parameters, were assessed before surgery and at the final follow-up.

RESULTS

Significant improvements were observed in clinical and radiographic outcomes in both groups after surgery. Postoperative Japanese Society for Surgery of the Foot scale and subscale scores of pain and shoes in the Self-Administered Foot Evaluation Questionnaire were not significantly different between the groups, whereas subscale scores of function, social, and health were greater in the varus group than in the neutral group at the final follow-up. Radiographic parameters, including TT angle and tibial axis-medial malleolus (TMM) angle, improved postoperatively and were not significantly different between the neutral (mean TT angle, 0.5 ± 0.7°; mean TMM angle, 16.0 ± 4.6°) and varus (meanTT angle, 0.4 ± 0.7°; meanTMM angle, 17.0 ± 5.3°) groups at the final follow-up. To achieve neutral alignment, adjunctive procedures were required more often in the varus group.

CONCLUSIONS

Outcomes of TAA using the TNK ankle prosthesis were favorable in patients with severe varus ankle and in those with neutral ankle without concomitant osteotomy. Satisfactory outcomes could be achieved in patients with severe varus ankle alignment after TAA without concomitant osteotomy.

TB-related technical enquiries received in Japan, 2017-2019

SETTING

Japan, an intermediate TB burden country.

OBJECTIVE

To review TB-related technical enquiries received at the Research Institute of Tuberculosis, Japan, from January 2017 to December 2019.

DESIGN

This was a cohort study.

RESULTS

A total of 2,197 enquiries were analysed. On average, 61.0 enquiries/month (range: 42-81) were received. The enquiry rates were highest for the Yamanashi (4.65/100,000 population) and Ishikawa (4.55) Prefectures, and lowest in the Yamagata (0.46) and Tochigi (0.56) Prefectures. The main organisations the enquirers belonged to were local governments (n = 1,585, 72.1%) and healthcare facilities (n = 307, 14.0%). The enquirers were medical doctors (n = 391, 17.8%), nurses (n = 1,207, 54.9%), other healthcare professionals (n = 57, 2.6%), the general public (n = 168, 7.6%) and others/unknown (n = 374, 17.0%). The most frequent enquiries were about TB diagnosis and treatment (n = 501, 22.8%), including laboratory diagnosis (n = 88, 4.0%), TB treatment in general (n = 93, 4.2%) and management of comorbidities (n = 86, 3.9%), followed by contact investigations (n = 385, 17.5%) and TB in foreigners (n = 344, 15.7%).

CONCLUSION

As the most frequent enquiries were about diagnosis and treatment of TB, the health ministry of Japan should maintain a few specialised TB institutions with TB physicians to provide technical assistance.

Steeper lateral posterior tibial slope and greater lateral-medial slope asymmetry correlate with greater preoperative pivot-shift in anterior cruciate ligament injury

PURPOSE

To investigate the association between posterior tibial slope (PTS) and preoperative pivot-shift phenomenon in anterior cruciate ligament (ACL)-injured knees.

METHODS

Fifty unilateral ACL-injured patients (mean age: 28.0 ± 11.4 years, 29 males) who underwent ACL reconstruction were retrospectively included. Patients with a history of injury to the ipsilateral knee joint, concomitant ligament injuries with ACL injury, and/or more than one year from injury to surgery, were excluded. Pivot-shift tests were performed preoperatively under general anaesthesia using an electromagnetic measurement system, and tibial acceleration (m/s²) during the posterior reduction of the tibia was measured. Medial and lateral PTS (°) were measured respectively using high-resolution CT images taken two weeks after surgery. Lateral-medial slope asymmetry was calculated by subtracting medial PTS from lateral PTS (lateral-medial PTS) and we evaluated the correlation between each PTS parameter (medial PTS, lateral PTS, and lateral-medial slope asymmetry) and tibial acceleration during the pivot-shift test. The level of significance was set at p < 0.05.

RESULTS

Medial PTS was 4.9 ± 2.0°, and lateral PTS was 5.2 ± 1.9°. The lateral-medial slope asymmetry was 0.3 ± 1.6° (range: -2.9 to 3.8). Tibial acceleration during the pivot-shift test in the ACL-injured knee was 1.6 ± 0.1 m/s². Preoperative tibial acceleration was positively correlated with lateral PTS (r = 0.436, p < 0.01), and lateral-medial slope asymmetry (r = 0.443, p < 0.01), while no significant correlation was found between preoperative tibial acceleration and medial PTS (r = 0.06, p = 0.70).

CONCLUSION

Preoperative greater tibial acceleration during the pivot-shift test was associated with steeper lateral PTS and greater lateral-medial slope asymmetry in ACL-injured knees. These findings improve our understanding of anterolateral rotatory knee laxity by linking tibial bony morphology to quantitative measurement of pivot-shift phenomenon. Surgeons should be aware that not only lateral PTS but also lateral-medial slope asymmetry are the factors associated with preoperative pivot-shift.

LEVEL OF EVIDENCE

Level IV.

Analysis of popliteal artery location for high tibial and distal tuberosity osteotomy using contrast-enhanced computed tomography

Background

Our objective was to evaluate the location of popliteal artery (PA) in osteotomy planes during high tibial osteotomy (HTO) and to determine a safer angle for screw drilling to the tibial tuberosity during distal tuberosity osteotomy (DTO).

Methods

Twenty knees in 20 patients who underwent contrast-enhanced computed tomography for cardiovascular diseases were examined. Osteotomy planes for open-wedge HTO (OWHTO) and hybrid closed-wedge HTO (hybrid CWHTO) were created using three-dimensional bone models. The distance from the posterior cortex of the tibia to the PA (dPC-PA) in the osteotomy planes was measured in the virtual osteotomy planes. The dangerous point (Point D1) was defined as the point 17.5 mm away from PA, setting the working length of the bone saw as 35 mm. The distance between the most medial point of the tibial cortex (Point M) and Point D1 in OWHTO and the most lateral point (Point L) and Point D1 in hybrid CWHTO were examined (dM-D1 and dL-D1, respectively). The location of Point D1 to the osteotomy line (%D1) was expressed as percentage, setting the start and end of the osteotomy line as 0% and 100%, respectively. To determine the safe angle for screw drilling in DTO, the angle between the line tangential to the medial cortex of the tibia and that passing through the center of the tibial tuberosity and PA were measured.

Results

In OWHTO and hybrid CWHTO, the mean dPC-PA was 10.6 mm (6.9–16.5 mm) and 10.2 mm (7.3–15.4 mm), respectively. The mean dM-D1 in OWHTO was 25.9 mm (24.6–27.2 mm) and dL-D1 in hybrid CWHTO was 5.1 mm (2.9–7.4 mm). The mean %D1 was 47.6 ± 3.7% in OWHTO and 9.3 ± 4.1% in hybrid CWHTO, respectively. The minimal angle between the two lines in DTO was 35.2°.

Conclusion

PAs could run within 10 mm from the posterior cortex in the osteotomy planes of HTO. Therefore, proper posterior protection is necessary when cutting posterior cortex. An angle of less than 35° against the medial cortex line would be safe for screw fixation to avoid vascular injury in DTO.

The incidence of tibial tunnel coalition is higher than femoral tunnel coalition in double-bundle anterior cruciate ligament reconstruction using hamstring autografts: A systematic review

INTRODUCTION

Intra-operative and postoperative coalition of tunnels may occur in double-bundle (DB) anterior cruciate ligament reconstruction (ACLR). However, the incidence and effect on clinical outcomes of tunnel coalition following primary DB ACLR using a hamstring autograft has yet be analyzed, and thus remains unknown. The objective of this systematic review was to identify the incidence of tunnel coalition upon DB ACLR using hamstring autografts and to elucidate any clinical outcomes and/or complications that tunnel coalition may have postoperatively.

HYPOTHESIS

The incidence of tunnel coalition would increase in respect to time from the index surgery, and that tunnel coalition would be related to poorer clinical outcomes compared to non-coalition cases.

METHODS

Three databases (PubMed, EMBASE, Cochrane Library) were searched in accordance with PRISMA and R-AMSTAR guidelines on June 15, 2020. Relevant studies were screened in duplicate and data regarding patient demographics, incidence of femoral and tibial tunnel coalition, and outcomes were extracted. Coalition rate was also compared between follow up at 1 month or less defined as "shorter-term", and 6 months or greater as "longer-term". Coalition is defined as the missing of a bony bridge between the two tunnels.

RESULTS

Thirty-six studies examining 1,574 patients, mean age 29.1 years, were included in this study. 29 studies (1,110 knees) reported the incidence of femoral coalition with a pooled rate of coalition of 8% (95% CI=4-12%). 28 studies (1,129 knees) reported an incidence of tibial coalition with a pooled rate of coalition of 21% (95% CI=13-30%). The incidence of tibial coalition was significantly higher than the incidence of femoral coalition across 21 comparative studies (OR=3.37, 95% CI=1.41-8.09, p=0.0065). Only two studies (111 knees) compared tunnel coalition and non-coalition groups for clinical outcome and no significant differences were observed with regards to Lysholm score, Tegner activity scale, and knee laxity measured with a KT-1000 arthrometer.

DISCUSSION

The rate of tibial tunnel coalition in DB ACLR is higher than femoral tunnel coalition, particularly at longer-term follow-up. Despite the higher radiographic evidence of coalition, the clinical effects of such remain to be ascertained, and further comparative studies are required to facilitate this understanding.

LEVEL OF EVIDENCE

IV, systematic review.

Novel therapy using a fish scale collagen scaffold for rotator cuff healing in rat models

BACKGROUND

Large and massive rotator cuff tears are challenging for surgeons because of postoperative complications such as repaired site retears. Recently, collagen extracted from fish scales has gained more attention because fish byproducts are considered a safer collagen source than other animal-derived scaffolds. This study aimed to evaluate the biological efficacy of tilapia scale-derived collagen scaffolds for rotator cuff repair in rat models.

METHODS

The infraspinatus tendon was resected from the greater tuberosity of Sprague-Dawley rats. In the control group, the tendon edge was sutured directly to the humeral head. In the augmentation group, the repaired site was augmented with a tilapia scale-derived collagen scaffold. Histologic examinations were performed at 2 and 4 weeks postoperatively via safranin O and immunofluorescence staining (isolectin B4 and type II collagen) in the bone-tendon junction. For mechanical analysis, the ultimate failure load of the tendon-humeral head complex was evaluated at 6 weeks postoperatively.

RESULTS

During safranin O staining, the repaired enthesis demonstrated greater proteoglycan staining in the augmentation group than in the control group at 4 weeks postoperatively. Compared to controls, the augmentation group had significantly higher vascular staining with isolectin B4 at 2 and 4 weeks postoperatively, type II collagen expression at 4 weeks postoperatively, and ultimate failure load at 6 weeks postoperatively.

CONCLUSION

Augmentation therapy using tilapia scale-derived type I collagen scaffolds promoted angiogenesis and fibrocartilage regeneration at the enthesis and provided higher mechanical strength than controls.

Assessment of the Ulnar Collateral Ligament of the Elbow Using Ultrasonic Shear Wave Elastography in Professional Baseball Players

BACKGROUND

Injury to the ulnar collateral ligament (UCL) of the elbow can cause chronic pain and loss of throwing ability. Ultrasonic shear wave elastography (SWE) is a new imaging method that can be used for quantitative assessment of tissue elasticity.

PURPOSE

To evaluate the properties of the UCL in professional baseball players using SWE.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

This study included 35 professional baseball players (mean age, 23.0 years) without elbow injuries. Both elbows of each player were examined using ultrasound, and comparisons between the dominant and nondominant arms were conducted. The thickness of the anterior bundle of the UCL at its midportion was measured in the resting position on ultrasound. We also measured the difference in the ulnohumeral joint space with and without gravity stress on the forearm. Tissue elasticity was evaluated using a built-in software program. The relationship between UCL elasticity and ultrasound findings was analyzed using the Pearson correlation coefficient.

RESULTS

The mean ± SD thickness of the UCL was significantly greater in the dominant arm versus the nondominant arm (6.0 ± 1.4 vs 5.3 ± 1.3 mm; P = .004). The mean joint space difference was significantly wider in the dominant arm as compared with the nondominant arm (0.81 ± 0.42 vs 0.52 ± 0.31 mm; P = .002), and the mean UCL elasticity was lower in the dominant arm than in the nondominant arm (34.9 ± 11.6 vs 43.3 ± 10.6 kPa; P = .002). UCL elasticity was negatively correlated with UCL thickness (r = -0.27; P = .02) and joint space difference (r = -0.34; P = .003).

CONCLUSION

In professional baseball players, the elbow UCL of the dominant arm demonstrated increased thickness, with a larger joint space gap on gravity stress and lower elasticity in SWE as compared with the nondominant arm. Greater medial joint laxity can be predicted by assessing the elasticity of the UCL using SWE.

Identification and characterization of slow‑cycling cells in Ewing sarcoma

Ewing sarcoma (ES) is an aggressive primary malignant bone tumor that predominantly affects children and young adults. Multimodal treatment approaches have markedly improved the survival of patients with localized ES. However, local recurrence and distant metastasis following curative therapies remain a main concern for patients with ES. Recent studies have suggested that slow-cycling cells (SCCs) are associated with tumor progression, local recurrence and distant metastasis in various types of cancers. According to the results of these studies, it was hypothesized that SCCs may play a critical role in tumor progression, chemoresistance and local/distal recurrence in patients with ES. The present study applied a label-retaining system using carboxyfluorescein diacetate succinimidyl ester (CFSE) to identify and isolate SCCs in ES cell lines. In addition, the properties of SCCs, including sphere formation ability, cell cycle distribution and chemoresistance, in comparison with non-SCCs were investigated. RNA sequencing also revealed several upregulated genes in SCCs as compared with non-SCCs; the identified genes not only inhibited cell cycle progression, but also promoted the malignant properties of SCCs. On the whole, the present study successfully identified SCCs in ES cells through a label-retaining system using CFSE. Moreover, to the best of our knowledge, the present study is the first to describe the characteristic properties of SCCs in ES. The findings of this study, if confirmed, may prove to be useful in elucidating the underlying molecular mechanisms and identifying effective therapeutic targets for ES.

Quadriceps tendon autograft for pediatric anterior cruciate ligament reconstruction results in promising postoperative function and rates of return to sports: A systematic review

PURPOSE

To assess the performance of the quadriceps tendon (QT) autograft in pediatric anterior cruciate ligament reconstruction (ACLR).

METHODS

A systematic search of MEDLINE, PubMed, and EMBASE was conducted on March 1, 2021. Studies of all levels of evidence reporting outcomes and/or complications after QT autograft ACLR in pediatric patients (≤ 18 years old) were eligible for inclusion. Study demographics, patient demographics, reported outcomes, and complications were abstracted. Screening and data abstraction were designed in accordance with PRISMA and R-AMSTAR guidelines. Descriptive statistics were presented when applicable, with data for heterogeneous outcomes presented in narrative summary fashion.

RESULTS

A total of 14 studies examining 596 patients (46.3% female), mean age 15.4 years, were included in this systematic review. Mean postoperative Lysholm scores ranged from 94.0 to 99.5. Mean postoperative IKDC subjective scores ranged from 75.9 to 94.0. Limb symmetry index ranged from 96.8 ± 10.4 to 100.4 ± 7.6% across multiple hop tests. Return to sports (RTS) rates ranged from 88.9 to 91.7%. Eleven studies reported postoperative complications, whereby 16 patients (4.8%) experienced contralateral complications and injuries. Forty-six patients (9.4%) experienced ipsilateral complications, including ten graft failures (2.5%) and two growth disturbances (0.6%).

CONCLUSIONS

QT autograft ACLR in the pediatric population retains the potential of regaining a preinjury level of knee stability, and yields promising postoperative function and rates of RTS, yielding comparable outcomes relative to HT autograft and the reference-standard BPTB ACLR that have previously been described in the literature. Moreover, use of the QT autograft is associated with low rates of postoperative complications, including graft failure and growth disturbances in this active and high-risk patient population in observational studies to date. Therefore, clinical equipoise exists to further appraise the influence of QT autograft on postoperative outcomes compared to aforementioned autograft options in a randomized control trial fashion.

LEVEL OF EVIDENCE

IV.

Survival Rate after Palliative Surgery Alone for Symptomatic Spinal Metastases: A Prospective Cohort Study

The effect of spine surgery for symptomatic spinal metastases (SSM) on patient prognosis remains unclear. This study aimed to reveal the prognosis of patients with SSM after spine surgery. One hundred twenty-two patients with SSM were enrolled in this prospective cohort study. The patients who received chemotherapy after enrollment were excluded. The decision of surgery depended on patient's willingness; the final cohort comprised 31 and 24 patients in the surgery and non-surgery groups, respectively. The patients were evaluated by their performance status (PS), activities of daily living (ADL) and ambulatory status. Survival was evaluated by the Kaplan-Meier method. The PS, ADL and ambulation were significantly improved in the surgery group compared to non-surgery group. The median survival was significantly longer in the surgery group (5.17 months, 95% confidence interval (CI) 3.27 to 7.07) than in the non-surgery group (2.23 months, 95% CI 2.03 to 2.43; p = 0.003). Furthermore, the patients with a better PS, ADL and ambulatory status had a significantly longer survival. Surgery improved the PS, ADL, ambulation and survival of patients with SSM. In the management of SSM, spine surgery is not only palliative but may also prolong survival.

Influence of Injury to the Kaplan Fibers of the Iliotibial Band on Anterolateral Rotatory Knee Laxity in Anterior Cruciate Ligament Injury: A Retrospective Cohort Study

BACKGROUND

Biomechanical cadaveric studies have shown that Kaplan fibers (KFs) of the iliotibial band play a role in controlling anterolateral rotatory knee laxity in anterior cruciate ligament (ACL) injury. However, in the clinical setting, the contribution of injury to KFs on anterolateral rotatory laxity remains unclear.

PURPOSE

To use magnetic resonance imaging (MRI) scans to detect concomitant KF injury in ACL-injured knees and to then examine the effect of KF injury on anterolateral rotatory laxity as measured by the pivot-shift test in a clinical setting.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

The study enrolled 91 patients with primary ACL tears (mean age 25 ± 11 years; 46 male and 45 female) whose MRI was conducted within 90 days after injury. KF injury was assessed by MRI according to previously reported criteria, and the patients were allocated to a KF injury group and a no-KF injury group. At the time of ACL reconstruction, the pivot-shift test was performed with the patient under anesthesia and quantitatively evaluated by tibial acceleration using an electromagnetic measurement system. Manual grading of the pivot-shift test was assessed according to guidelines of the International Knee Documentation Committee. The data were statistically compared between the 2 groups using Mann-Whitney U test and Fisher exact test (P < .05).

RESULTS

KFs were identified in 85 patients (93.4%), and KF injury was detected in 20 of the 85 patients (23.5%). No significant differences were observed between the KF injury group (n = 20) and the no-KF injury group (n = 65) in demographic characteristics, the period from injury to MRI (8.0 ± 14.0 days vs 8.9 ± 12.1 days, respectively), the rate of meniscal injury (50.0% vs 53.8%), or the rate of anterolateral ligament injury (45.0% vs 44.6%). Regarding the pivot-shift test, no significant differences were observed in tibial acceleration (1.2 m/s² [interquartile range, 0.5-2.1 m/s²] vs 1.0 m/s² [interquartile range, 0.6-1.7 m/s²], respectively) or manual grading between the 2 groups.

CONCLUSION

Concomitant KF injury did not significantly affect the pivot-shift phenomenon in acute ACL-injured knees. The findings suggest that the contribution of KF injury to anterolateral rotatory knee laxity may be limited in the clinical setting.

Using deep learning for ultrasound images to diagnose carpal tunnel syndrome with high accuracy

Recently, deep learning (DL) algorithms have been adapted for the diagnosis of medical images. The purpose of this study was to detect image features using DL without measuring median nerve cross-sectional area (CSA) in ultrasonography (US) images of carpal tunnel syndrome (CTS) and calculate the diagnostic accuracy from the confusion matrix obtained. US images of 50 hands without CTS and 50 hands diagnosed with CTS were used in this study. The short-axis image of the median nerve was visualized, and 5000 images of both groups were prepared. Forty hands in each group were used as training data for the DL algorithm, while the remainder were used as test data. Transfer learning was performed using three pre-trained models. The confusion matrix and receiver operating characteristic curves were used to evaluate diagnostic accuracy. Furthermore, regions where DL was determined to be important were visualized. The highest score had an accuracy of 0.96, precision of 0.99 and recall of 0.94. Visualization of the important features revealed that the DL models focused on the epineurium of the median nerve and the surrounding soft tissue. The proposed technique enables the accurate prediction of CTS without measurement of the CSA.

Analysis of bone union after medial closing wedge distal femoral osteotomy using a new radiographic scoring system

INTRODUCTION

To compare bone union after medial closing wedge distal femoral osteotomy (MCWDFO) with that after lateral closing wedge distal femoral osteotomy (LCWDFO) using a novel scoring system.

MATERIALS AND METHODS

The data of 30 patients who received biplanar MCWDFO for valgus knees (MCWDFO group) were retrospectively examined and compared to that of 22 patients (25 knees) who underwent biplanar LCWDFO via a double-level osteotomy (DLO) for varus knees (LCWDFO group). The progression of bone union of the transverse osteotomy plane in the femur was assessed using a newly developed scoring system using radiographs taken immediately after surgery and 3 and 6 months postoperatively. The scoring system is based on a scale of zero to six points with higher scores indicating better bone union. The incidence of hinge fractures was assessed using CT images, and the rates of reoperation were evaluated using medical record data.

RESULTS

The mean bone union score was significantly lower in the MCWDFO group than in the LCWDFO group 3 months (2.1 ± 1.9 vs. 3.7 ± 1.7, P < 0.01) and 6 months (3.8 ± 2.1 vs 4.9 ± 1.5, P < 0.05) postoperatively. The incidence ratio of hinge fractures was significantly higher in the MCWDFO group than in the LCWDFO group (70.0% vs. 32.0%, P < 0.01). Two patients in the MCWDFO group underwent reoperation for delayed bone union or non-union.

CONCLUSION

Bone union progression was slower and hinge fractures were more frequently observed after MCWDFO than after LCWDFO via DLO. MCWDFO is technically challenging, and patients must be monitored closely during and after surgery.

Biochemical Markers of Aging (Advanced Glycation End Products) and Degeneration Are Increased in Type 3 Rotator Cuff Tendon Stumps With Increased Signal Intensity Changes on MRI

BACKGROUND

Advanced glycation end products (AGEs) are end products of protein glycation that bind to the receptor for AGEs (RAGE) and activate nicotinamide adenine dinucleotide phosphate oxidase (NOX), resulting in increased oxidative stress and rotator cuff fragility. Stump classification using the signal intensity ratio of the tendon rupture site to the deltoid muscle in the coronal view of T2-weighted fat-suppressed magnetic resonance imaging (MRI) scans is an indicator of clinical outcomes after rotator cuff repair surgery. Comparing the signal intensities of the deltoid (D) and rotator cuff tears (C), Ishitani et al. classified C/D <0.8 as type 1, 0.8 to 1.3 as type 2, and >1.3 as type 3.

HYPOTHESIS/PURPOSE

It was hypothesized that the oxidative stress and collagen degeneration that occur in the rotator cuff due to accumulation of AGEs can be assessed on MRI scans (stump classification). Therefore, this study aimed to compare AGE-related factors in the rotator cuff tear site tissues based on stump classification.

STUDY DESIGN

Descriptive laboratory study.

METHODS

The authors included 30 patients (11 with type 1, 9 with type 2, and 10 with type 3; mean age, 62.3 years) who underwent surgery for complete rotator cuff tears at our hospital. Tendon tissue was harvested from the torn rotator cuff site during surgery for tissue and cell evaluation.

RESULTS

There was no significant difference in the mean age according to stump classification. The number of patients with diabetes was significantly larger in type 3 than in the other types (P < .05). Tissue evaluation showed significantly higher expression of AGE and RAGE staining in type 3 than in the other types (~6.7-fold; P < .01). Cell evaluation showed that the expression rates of reactive oxygen species and apoptosis were significantly higher in type 3 than in the other types (~4.3-fold; P < .01). Gene expression by real-time polymerase chain reaction showed significantly higher RAGE (~5.1-fold), NOX (~5.3-fold), and IL (~3.0-fold) in type 3 than in the other types (P < .05).

CONCLUSION

Stump classification type 3 exhibited the highest accumulation of AGEs and the highest oxidative stress and apoptosis, suggesting a high degree of degeneration and inflammation. Imaging based on stump classification reflects the degeneration and fragility of the torn rotator cuff site.

CLINICAL RELEVANCE

This study provides evidence of a relationship between stump classification, which reflects rotator cuff fragility on MRI, and pathologies related to advanced glycation end products.

Association Between Meeting Return-to-Sport Criteria and Psychological Readiness to Return to Sport After Anterior Cruciate Ligament Reconstruction

Background:

The relationship between meeting return-to-sport criteria and psychological readiness after anterior cruciate ligament (ACL) reconstruction is unknown.

Purposes:

To examine (1) whether patients who met 1 of the criteria for return to sport had higher psychological readiness than those who did not meet any of the criteria and (2) if those who met more criteria had higher psychological readiness.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

This study included 144 patients who underwent unilateral ACL reconstruction. All patients had regularly participated in some sport activities before an ACL rupture. At 12 months postoperatively, each patient completed 3 knee function tests (isokinetic quadriceps strength, isokinetic hamstring strength, and single-leg hop distance) and 2 self-reported measures (International Knee Documentation Committee [IKDC] 2000 subjective form and ACL–Return to Sport after Injury [ACL-RSI] scale); the ACL-RSI scale was used to measure psychological readiness to return to sport. The 4 criteria for return to sport were a limb symmetry index (LSI) ≥90% for each of the 3 function tests in addition to an IKDC score ≥90. Multivariate regression analysis was used to determine the association between meeting the individual criteria and the ACL-RSI score. In addition, the patients were divided into 5 groups according to the number of criteria met, and the Kruskal-Wallis and Steel-Dwass tests were used to compare the ACL-RSI scores among the groups.

Results:

Overall, 23 patients (16.0%) met none of the criteria for return to sport, 27 (18.7%) met 1 of the criteria, 34 (23.6%) met 2 criteria, 35 (24.3%) met 3 criteria, and 25 (17.4%) met all 4 criteria. Meeting the criteria for the hamstring strength LSI (P = .002), single-leg hop distance LSI (P = .004), and IKDC subjective score (P < .001) was each associated with higher ACL-RSI scores. Significant differences in ACL-RSI scores were found between patients who met none versus 2, 3, and 4 of the return-to-sport criteria (P < .001 for all) and between patients who met 1 versus 4 criteria (P < .001).

Conclusion:

Meeting return-to-sport criteria was positively associated with psychological readiness, and the patients who met multiple criteria had higher psychological readiness.

Clinical Outcomes and Prognostic Factors in Soft Tissue Sarcoma Patients After Unplanned Excision

Purpose

Soft tissue sarcomas (STSs) constitute a group of rare, heterogeneous tumors representing approximately 1% of all cancers. Owing to the rarity and pathological diversity of the disease, unplanned excision (UE) has often been performed for STS, resulting in an unfavorable prognosis. This study aimed to clarify clinical outcomes and prognostic factors in STS patients who underwent UE.

Patients and Methods

In a retrospective review of the medical records of patients with STS who underwent surgery at our institution between 1999 and 2015, patients were enrolled to either a UE group or a planned excision (PE) group. An analysis was then conducted to identify factors associated with prognosis after UE.

Results

Of 134 patients undergoing surgery for STS, 110 were enrolled to the PE group and 24 to the UE group. The median size of the primary tumor was significantly smaller, and more lesions were located in the superficial layer in the UE group than in the PE group. In addition, plastic reconstruction after additional radical resection was required significantly more often in the UE group than in the PE group. No significant difference in overall survival, local recurrence-free survival, or disease-free survival (DFS) between the UE and PE groups was observed; however, metastasis-free survival was significantly better in the UE group. In the UE group, poorer DFS was associated with older age (≥61 years) and a larger primary tumor (≥2.9 cm).

Conclusion

A prognosis similar to that in patients undergoing PE could be achieved by appropriate additional surgeries in patients initially undergoing UE. However, UE for STS should be avoided, especially in older patients and those with a larger primary tumor.

Functional Outcomes and Subsequent Surgical Procedures After Arthroscopic Suture Versus Screw Fixation for ACL Tibial Avulsion Fractures: A Systematic Review and Meta-analysis

Background:

Although arthroscopic screw fixation and suture fixation are mainstream interventions for displaced anterior cruciate ligament avulsion fractures of the tibia, the differences in clinical outcomes between them remain inconclusive.

Purpose:

To conduct a meta-analysis comparing the clinical and functional outcomes between arthroscopic screw fixation and suture fixation for tibial avulsion fractures.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

A systematic review was conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and using the PubMed, Embase, and Cochrane Central Register of Controlled Trials databases. Inclusion criteria were English-language articles that compared functional outcomes after screw fixation versus suture fixation for tibial avulsion fractures and had at least 1-year follow-up. Relevant data were extracted and analyzed statistically using the Mantel-Haenszel method and variance-weighted means. Random-effects models were used to generate pooled relative risk (RR) estimates with confidence intervals (CIs).

Results:

Of 1395 articles initially identified, we included 5 studies with 184 patients (91 patients with screw fixations and 93 patients with suture fixations). The pooled results indicated similar postoperative outcomes for screw fixation and suture fixation: Lysholm score (mean difference [MD], −0.32 [95% CI, −6.08 to 5.44]; P = .91), proportion of International Knee Documentation Committee score grade A (74% vs 74%; RR, 0.63 [95% CI, 0.10-3.95]; P = .63), Tegner score (MD, 0.10 [95% CI: −1.73 to 1.92]; P = .92), and Lachman test results (stable knee joint, 82% vs 82%; RR, 0.99; 95% CI: 0.85-1.16; P = .90). Patients in the screw fixation group had a significantly higher overall subsequent surgery rate (46% vs 19%; RR, 2.33; 95% CI,1.51-3.60; P = .0001) and implant removal rate (44% vs 3%; RR, 8.52; 95% CI, 3.58-20.29; P < .00001) compared with those in the suture fixation group. Nonimplant-related subsequent surgery rates were similar for the 2 groups.

Conclusion:

The findings indicated a higher risk of subsequent surgery (RR, 2.33) and implant removal (RR, 8.52) after screw fixation when compared with suture fixation for tibial avulsion fractures. However, there were no significant differences in clinical outcome scores between the 2 techniques.

Comparison of Clinical Outcomes Between Ceramic-Based Total Ankle Arthroplasty with Ceramic Total Talar Prosthesis and Ceramic-Based Total Ankle Arthroplasty

BACKGROUND

Total ankle arthroplasty (TAA) has become one of the standard surgical treatments for patients with end-stage ankle osteoarthritis (OA). In recent years, TAA with total talar prosthesis (combined TAA) has been used for ankle OA patients with talar osteonecrosis, with severe talar collapse, or with subtalar joint OA. The purpose of this study was to investigate the functional and clinical outcomes of combined TAA, compared with conventional TAA.

METHODS

Forty-six ankles (44 patients, 32 women/12 men) that underwent conventional TAA with mean follow-up of 42 months, and 26 ankles (25 patients, 18 women/7 men) that underwent combined TAA with mean follow-up of 46 months were included. Clinical outcomes, which included ankle range of motion (ROM), the Japanese Society for Surgery of the Foot (JSSF) ankle-hindfoot scale, the Self-Administered Foot Evaluation Questionnaire (SAFE-Q), and complications were compared between the groups.

RESULTS

The preoperative ROM was significantly worse in combined TAA for both dorsiflexion and plantarflexion; however, in the final ROM, there was no significant difference between the groups. There was no significant difference in JSSF scale and SAFE-Q between the groups. Revision rate was 10.9% in conventional TAA and 0% in combined TAA.

CONCLUSION

In this small series, at an average of 3.5 years, we found no significant difference in clinical results between conventional TAA and combined TAA; however, the revision rate was higher in conventional TAA.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

A phase I/IIa clinical trial of third-generation autologous chondrocyte implantation (IK-01) for focal cartilage injury of the knee

Background/objective

The purpose of this study was to report the outcomes of a clinical trial conducted in Japan to assess the safety and effectiveness of third-generation autologous chondrocyte implantation (ACI) using IK-01 (CaReS™), which does not require flap coverage, in the treatment of patients with focal cartilage injury of the knee.

Methods

This was an open label, exploratory clinical trial. Patients were enrolled between June 2012 and September 2016. The primary endpoint of the study was the International Knee Documentation Committee (IKDC) score at 52 weeks after implantation. The IKDC, Lysholm, and visual analog scale (VAS) scores were evaluated at the time of screening and at 4, 12, 24, 36, and 52 weeks after implantation. Improvements from the baseline scores were evaluated using the equation “(postoperative score) − (preoperative score).” Magnetic resonance imaging (MRI) was performed at 2, 12, 24, and 52 weeks after implantation, and MRI measurements were evaluated using T1 rho and T2 mapping.

Results

Nine patients were enrolled in this study and were examined for safety. Product quality did not satisfy the specification in one patient, and bacterial joint infection occurred in one patient. As a result, seven patients were included in the outcome analyses. The mean IKDC score significantly improved from 36.4 preoperatively to 74.1% at 52 weeks after implantation (p < 0.0001). The mean Lysholm and VAS scores also significantly improved from 39.6 to 57.4 to 89.6 and 22.9, respectively, after surgery. In the MRI evaluation, the T1 rho and T2 values of the implanted area were similar to those of the surrounding cartilage at 52 weeks after implantation.

Conclusions

Third generation ACI (IK-01) can be an effective treatment option for focal cartilage defects of the knee; however, surgeons must pay careful attention to the risk of postoperative joint infection.