Anterior-Posterior Center of Pressure Is Associated With Knee Extensor Moment During Landing After Anterior Cruciate Ligament Reconstruction

CONTEXT

A reduced knee extensor moment (KEM) in the involved limb and asymmetry in the KEM during landing tasks are observed after anterior cruciate ligament reconstruction (ACLR). There is limited information about the association of kinetic and kinematic parameters with the KEM during landing after ACLR. This study investigated the association of the anterior-posterior center of pressure (AP-COP) position, vertical ground reaction force (VGRF), and lower limb joint angles with the KEM during landing in female athletes following ACLR.

DESIGN

Cross-sectional study.

METHODS

Twenty-two female athletes who underwent ACLR performed a drop vertical jump at 7.9 (1.7) months after surgery. We evaluated the KEM, AP-COP position, VGRF, and sagittal plane hip, knee, and ankle angles using a 3-dimensional motion analysis system with force plates.

RESULTS

The peak KEM in the involved limb was significantly smaller than that in the uninvolved limb during landing (1.43 [0.33] N·m/kg/m vs 1.84 [0.41] Nm/kg/m, P = .001). The VGRF in the involved limb was significantly smaller than that in the uninvolved limb (11.9 [2.3] N/kg vs 14.6 [3.5] N/kg, P = .005). The limb symmetry index of the KEM was predicted by that of the VGRF (P < .001, R2 = .621, β = 0.800). The KEM was predicted by the AP-COP position in the involved limb (P = .015, R2 = .227, β = 0.513) and by the VGRF in the uninvolved limb (P = .018, R2 = .213, β = 0.500). No significant correlation was noted between the KEM and the lower limb joint angles.

CONCLUSIONS

The AP-COP position and VGRF were associated with the KEM during landing. Evaluating the VGRF and AP-COP position, not the lower limb joint angles, may contribute to understanding the KEM during double-leg landing after ACLR in the clinical setting.

A new neural network model that detects graft ruptures and contralateral anterior cruciate ligament injuries

PURPOSE

The purpose of this study was to develop a neural network model for predicting second anterior cruciate ligament (ACL) injury risk following ACL reconstruction using patient features from medical records.

METHODS

Of 486 consecutive patients who underwent primary unilateral ACL reconstruction, 386 patients (198 women, 188 men) with a mean age of 25.1 ± 11.6 years were included in this study. Fifty-eight features, including demographic data, surgical, preoperative and postoperative data, were retrospectively collected from medical records, and features with an incidence of less than 5% were excluded. Finally, 14 features were used for the analysis. The multilayer perceptron was composed of four hidden layers with a rectified linear unit as activation and was trained to maximise the area under the receiver-operating characteristic curve (auROC). Subsequently, validation was carried out through a rigorous threefold cross-validation process. To ascertain the most efficacious combination of features with the highest auROC, a single feature with the least impact on auROC maximisation was systematically eliminated from the comprehensive variable set, ultimately resulting in the retention of a mere two variables.

RESULTS

The median follow-up period was 50.5 (24-142) months. Fifty-seven knees had a second ACL injury, with a graft rupture rate of 7.7% and a contralateral injury rate of 6.9%. The maximum auROC for predicting graft rupture was 0.81 with two features: young age and hamstring graft. Meanwhile, the maximum auROC for predicting contralateral ACL injury was 0.74 with seven features, including young age, presence of medial meniscus tear, small body mass index, hamstring graft, female sex and medial meniscus repair or treatment.

CONCLUSION

A neural network model with patient features from medical records detected graft ruptures and contralateral ACL injuries with acceptable accuracy. This model can serve as a new, useful tool in clinical practice to inform decisions about ACL reconstruction and retuning to sports postoperatively.

LEVEL OF EVIDENCE

Level IV.

Association Between MRI Signal Intensity of the Repaired Lateral Meniscus and Residual Anterolateral Knee Laxity After ACL Reconstruction

Background

Anterolateral knee laxity (ALLx) has been linked to tears of the lateral meniscus (LM) and anterior cruciate ligament (ACL) injury.

Purpose

To investigate the longitudinal relationship between the signal intensity (SI) of the repaired LM on magnetic resonance imaging (MRI) and residual ALLx after ACL reconstruction (ACLR).

Study Design

Cohort study; Level of evidence, 3.

Methods

Included were 87 patients who underwent double-bundle ACLR and lateral meniscal repair (mean age, 23.5 years; body mass index, 23.7 kg/m2; 56 women) at a single institution between 2010 and 2019. Proton density-weighted (PDW) and T2-weighted (T2W) MRI was performed at 3, 6, and 12 months postoperatively, and the SI ratio (SIR) was calculated as (SI of the repaired LM)/(SI of the posterior cruciate ligament). At the 12-month follow-up, ALLx was evaluated using the pivot-shift test; an International Knee Documentation Committee grade ≥1 indicated residual ALLx.

Results

Overall, 12 patients (13.8%) exhibited ALLx at 12 months postoperatively. At 3 months postoperatively, the SIR on PDW images (SIR-PDW) was significantly higher in patients with ALLx versus those without ALLx (1.98 ± 0.77 vs 1.49 ± 0.52, respectively; P = .007); there was no difference in the SIR on T2W images between the groups. SIR-PDW at 3 months postoperatively was correlated negatively with patient age (r = -0.308, P = .004). When patients were stratified into a younger (≤22 years; n = 53; ALLx = 7 [13.2%]) and an older (>22 years; n = 34; ALLx = 5 [14.7%]) group, the area under the receiver operating characteristic curves (AUCs) for SIR-PDW in the younger group were statistically significant for predicting the prevalence of ALLx at all follow-up times (AUCs, 0.733-0.788) with optimal cutoff values of 2.00 at 3 months, 1.50 at 6 months, and 1.50 at 12 months. Logistic regression analysis revealed that if younger patients consistently had higher SIR-PDW values than the cutoff values, they were more likely to have residual ALLx (odds ratios, 10.24-23.57).

Conclusion

For younger patients who underwent both ACLR and lateral meniscal repair, higher MRI SI of the repaired LM was associated with a higher prevalence of residual ALLx.

Cartilage regeneration is related to superior mid-term patient-reported outcomes after open-wedge high tibial osteotomy

PURPOSE

Medial open-wedge high tibial osteotomy (OWHTO) is related to cartilage improvement in the medial compartment. This study aimed to evaluate factors associated with cartilage improvement and patient-reported outcomes (PRO) after OWHTO. It was hypothesised that cartilage improvement is associated with favourable PRO.

METHODS

This retrospective study included 94 patients who underwent OWHTO. The mean follow-up period was 5 years. The weight-bearing line ratio (WBLR) was defined as the ratio of the distance from the medial tibial edge to the tibial insertion of the weight-bearing line and the tibial width. The International Cartilage Research Society grade evaluated the medial femoral condyle (MFC) and medial tibial plateau (MTP) at initial and second-look arthroscopy, and cartilage improvement after OWHTO was assessed. Postoperative knee injury and osteoarthritis outcome scores (KOOS) were compared between the groups with improved and non-improved cartilage. Additionally, factors related to cartilage improvement and postoperative KOOS scores were analysed.

RESULTS

Regarding the MFC, KOOS pain, symptoms, activities of daily living (ADL) and quality of life (QOL) were significantly higher in the cartilage-improved group than in the non-improved group (p = 0.012, 0.003, 0.001, 0.006), and cartilage improvement was significantly related to KOOS pain, ADL and QOL (p = 0.021, 0.039, 0.013). In addition, the postoperative WBLR was associated with cartilage improvement, with a cutoff value of 54.0% (p = 0.046). Regarding the MTP, KOOS ADL and QOL (p = 0.026, 0.022) were significantly higher in the cartilage-improved group than in the nonimproved group. Body mass index (BMI) was significantly related to the postoperative QOL (p = 0.018) and associated with cartilage improvement, with a cutoff value of 25.9 kg/m2 (p = 0.002).

CONCLUSION

A postoperative WBLR greater than 54.0% and a preoperative BMI below 25.9 kg/m2 were associated with cartilage improvement, positively impacting PRO after OWHTO.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Therapeutic effect of knee extension exercise with single-joint hybrid assistive limb following total knee arthroplasty: a prospective, randomized controlled trial

The single-joint hybrid assistive limb (HAL-SJ), an exoskeletal robotic suit, offers functional improvement. In this prospective randomized controlled trial, we investigated the therapeutic effects of knee extension exercises using the HAL-SJ after total knee arthroplasty (TKA). Seventy-six patients with knee osteoarthritis were randomly assigned to HAL-SJ or conventional physical therapy (CPT) groups. The HAL-SJ group underwent exercise using the HAL-SJ for 10 days postoperatively, in addition to CPT; the CPT group underwent only CPT. Pain intensity and active and passive knee extension angles were evaluated preoperatively and on postoperative days 1-10 and weeks 2 and 4. Performance tests and Knee Injury and Osteoarthritis Outcome Scores (KOOS) were evaluated preoperatively and at postoperative weeks 2 and 4. Statistical analysis showed that the HAL-SJ group significantly improved active and passive knee extension angles compared with the CPT group. The HAL-SJ group showed immediate improvement in active knee extension angle through day 5. There were no significant differences in results between the performance tests and KOOS. Knee extension exercises with the HAL-SJ improved knee pain and the angle of extension in the acute phase after TKA.

Association between swallowing disorder and prevertebral hyperintensity on magnetic resonance imaging in patients after cervical cord injury without major fracture

This study aimed to clarify the association between swallowing disorder and prevertebral hyperintensity on magnetic resonance imaging (MRI) in patients with cervical spinal cord injury (CSCI) without a major fracture. This retrospective observational study included 30 patients who were diagnosed with acute CSCI without a major fracture (mean age: 69.3 years, 27 men). Swallowing disorder was defined as tube-dependent nutrition because of obvious aspiration 28 days after injury. The high-intensity area (HIA) and anteroposterior width (HIW) of the prevertebral space at C1-7 levels were measured using MRI short-TI inversion recovery midsagittal images. Receiver operating characteristic curve analysis was used to determine the optimal cutoff values of the HIA for predicting swallowing disorder. The incidence of swallowing disorder after CSCI was 16.7%. The HIA was significantly higher in the swallowing disorder group (median, 409.0 mm2) than in the non- swallowing disorder group (median, 159.1 mm2) (P = .04). There was no significant difference in HIW between the two groups. The optimal cutoff point of the HIA was measured at 203.2 mm2 with 80.0% and 20.0% sensitivity and specificity, respectively, with an area under the curve of 0.848 (95% confidence interval, 0.657-1.000, P = .01). The prevertebral hyperintensity area on MRI for swallowing disorder in patients after cervical cord injury without skeletal injury is associated with swallowing disorder. The optimal cutoff point of the area was determined to be 203.2 mm2.

Arthroscopic Hip Capsular Repair Improves Patient-Reported Outcome Measures and Is Associated With a Decreased Risk of Revision Surgery and Conversion to Total Hip Arthroplasty

Purpose

To perform a systematic review to assess the effect of capsular repair compared with nonrepair on patient-reported outcome measures (PROMs) and conversion to total hip arthroplasty (THA) after hip arthroscopy in patients with femoroacetabular impingement syndrome.

Methods

We initially searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and PubMed databases, as well as ongoing clinical trials (https://clinicaltrials.gov), on December 15, 2022. The eligibility criteria were randomized controlled trials (Level Ⅰ) and prospective comparative studies (Level II) of patients who underwent capsular repair and nonrepair via hip arthroscopy with a minimum follow-up period of 2 years. We registered this protocol a priori on PROSPERO (identification No. CRD42021239306). We assessed the risk of bias using the Methodological Index for Non-randomized Studies (MINORS) appraisal tool.

Results

This review included 5 studies with a total of 639 patients (270 with capsular repair [average age, 35.4 years; 41% female patients] and 369 with nonrepair [average age, 37.3 years; 38% female patients]). In the included studies, surgical procedures consisting of labral repair and pincer or cam osteoplasty were performed via hip arthroscopy. The modified Harris Hip Score was measured in all the included studies, and the standardized mean difference in PROMs for capsular repair versus nonrepair in the included studies was 0.42 (95% confidence interval [CI], 0.20 to 0.63). A sensitivity analysis of randomized controlled trials achieved consistent results (standardized mean difference in PROMs, 0.31; 95% CI, 0.02 to 0.60). Capsular repair was not associated with a reduction in revision surgery (risk difference, -0.02; 95% CI, -0.06 to 0.03; 26 of 270 patients with capsular repair vs 42 of 369 with nonrepair) but was associated with a reduction in conversion to THA (risk difference, -0.05; 95% CI -0.09 to -0.01; 12 of 270 patients with capsular repair vs 38 of 369 with nonrepair). The average Methodological Index for Non-randomized Studies (MINORS) score in the included studies was 20.

Conclusions

Patients who undergo capsular repair in conjunction with other arthroscopic hip preservation techniques have better PROMs and a lower incidence of THA conversion.

Level of Evidence

Level II, systematic review of Level I and II investigations.

Greater medial proximal tibial slope is associated with bone marrow lesions in middle-aged women with early knee osteoarthritis

BACKGROUND

Bone marrow lesion (BML) is an important magnetic resonance finding (MRI) finding that predicts knee osteoarthritis. The purpose of this study was to investigate the influence of proximal tibial morphology on BML, including the spreading root sign (SRS), in women without radiographic knee osteoarthritis (OA). It was hypothesized that varus alignment and a greater posterior tibial slopes (PTS) are associated with BML.

MATERIALS AND METHODS

A total of 359 female volunteers without knee OA who were participants in the Iwaki Health Promotion Project in 2017 or 2019 were enrolled. Participants were divided into the non-OA and early knee OA (EKOA) groups based on the Luyten's classification criteria. The presence of pathological cartilage lesions, BMLs, attritions, meniscal lesions and effusions was scored on T2-weighted fat-suppressed magnetic resonance imaging (MRI) according to the Whole-Organ MRI Scoring system. The medial proximal tibial angle (MPTA) and medial and lateral PTS (MPTS and LPTS, respectively) were measured. Regression and receiver operating characteristic (ROC) analyses were performed to reveal the relationship between BMLs and proximal tibial morphological parameters.

RESULTS

Of the 359 participants, 54 (15%) were classified as having EKOA. The prevalence of cartilage lesions, BMLs, attritions, meniscal lesions and effusions was higher in the EKOA group than in the non-OA group. The two groups had no significant difference in the proximal tibial parameters. Regression analysis revealed that age and a smaller MPTA were associated with BML in both groups. Attrition (p = 0.029) and the MPTS (p = 0.025) were positively associated with BML in the EKOA group.

CONCLUSION

The prevalence of BMLs was higher in women with EKOA and correlated with the varus and greater posterior slopes in those without radiographic knee OA.

LEVEL OF EVIDENCE

Level III, retrospective case-control study.

Concomitant Lateral Meniscus Tear is Associated with Residual Rotatory Knee Instability 1 Year after Anterior Cruciate Ligament Reconstruction: Case-cohort Study

Lateral meniscus tear (LMT) accompanied by anterior cruciate ligament (ACL) injuries has been reported to provoke rotatory instability of the affected knee joint. Unfortunately, these previous papers did not determine whether LMT-derived rotatory knee instability is residual because only preoperative or time zero data exists. This study aimed to longitudinally investigate how the prevalence of comorbid LMT is associated with residual rotatory knee instability (RKI) 1 year after ACL reconstruction (ACLR). A total of 327 patients who underwent double-bundle ACLR (average age: 23.4 years, body mass index: 23.5 kg/m2, 215 females). The patients were divided into three groups based on arthroscopy: 1) intact lateral meniscus (LM); 2) unrepaired LMT; 3) repaired LMT. At the 1-year follow-up, the pivot-shift test was performed. The prevalence of RKI, determined according to IKDC grades (grade ≥1 denoted RKI), was compared with chi-square or Fisher's exact tests. Thirty-eight patients (11.6%) had RKI; 203 subjects (62.1%) showed LMT, and 124 patients were diagnosed with an intact LM. Out of the 203 patients, 79 (38.9%) underwent LM repair. RKI was more prevalent in the LMT group than in the intact group (13.8% versus 8.1%, p = 0.117; Odds ratio: 1.499 [95%CI: 0.864 - 2.600]). In addition, the prevalence of RKI was significantly higher in the LM-repair group than in the intact-LM group (17.7% versus 8.1%, p = 0.038; Odds Ratio: 2.455 [95%CI: 1.032 - 5.842]). Medial meniscus tear (MMT) was detected in 113 patients (34.6%); RKI prevalence was not statistically different between the intact-MM group and the MMT group (12.2% versus 10.6%, p = 0.681). The current cohort study clarified that LMT comorbid with ACL injury was longitudinally associated with increased RKI prevalence 1 year after ACLR. Therefore, patients who underwent both ACLR and LM repair demonstrated a significantly higher prevalence of residual RKI.

Association between injury severity scores and clinical outcomes in patients with traumatic spinal injury in an aging Japanese society

The Injury Severity Score (ISS) is widely used to evaluate patients with multiple injuries. This study investigated the association between ISS and clinical outcomes of patients with spinal cord injury (SCI) in an aging Japanese population. This retrospective cohort study investigated patients admitted to a Japanese university hospital. In the study, 89 patients with traumatic SCI were included. Traumatic SCI was categorized as monotrauma or polytrauma, and the ISS was used to evaluate trauma severity. Spearman's correlation coefficient was used to estimate the correlation between ISS and the American Spinal Injury Association (ASIA) motor score, Barthel Index (activities of daily living assessment), and the European Quality of Life (QOL) scale (EQ5d) as an assessment of QOL at admission or the last follow-up with the adjustment for age, sex, and body mass index. Return to home and work were analyzed using the chi-squared test after the ISS was divided into three groups (<14, 14-19, and 20). The mean ISS was significantly higher for polytrauma than monotrauma. Significant negative correlations between the ISS and ASIA motor scores at the first visit (P < .001, r = -0.37) and the last follow-up (adjusted, P = .007, r = -0.30) were observed. The Barthel Index was also negatively correlated with ISS at the first visit (P = .04, r = -0.21) and at the last follow-up period (P < .001, r = -0.35). Moreover, ISS was significantly negatively correlated with EQ5d score at the last follow-up (P = .01, r = -0.28). The chi-squared test demonstrated that patients with an ISS of < 14 returned home (P = .03), while those with an ISS of < 19 returned to work (P = .02). ISS is associated with paralysis, activities of daily living, QOL, and lifestyle in patients with SCI and is an important initial injury assessment method.

The effects of combined early oral health care and early mobilisation on the incidence of stroke-associated pneumonia

OBJECTIVE

To investigate the effects of combined early oral healthcare and early mobilisation on the incidence of stroke-associated pneumonia during hospitalisation of acute stroke patients.

MATERIALS AND METHODS

In this single-centre, non-blinded, before-and-after cohort study, patients received basic stroke rehabilitation by a multidisciplinary team within 72 h of symptom onset from July to September 2016 and from July to September 2018. Patients were divided into two groups: 1) patients who received combined early oral healthcare and early mobilisation (early intervention group) (n=107), and 2) patients who received usual care (control group) (n=107). The relationship between the stroke-associated pneumonia incidence and prognosis was examined.

RESULTS

The early intervention group had a significantly lower incidence of stroke-associated pneumonia than the control group (0.93% vs. 7.48%; P=0.01). Moreover, the early intervention group had a significantly lower proportion of patients who died or required medical care because of recurrent pneumonia at discharge (0.93% vs. 5.6%; P=0.04). In contrast, there were no significant differences between the two groups regarding the Revised Hasegawa's Dementia Scale on day 14 (22.5 vs. 23; P=0.87), Functional Independence Measure on day 14 (112 vs. 116; P=0.06), and rate of total oral diet (Food Intake LEVEL Scale ≥7) at discharge (95.2% vs. 93.5%; P=0.55).

CONCLUSIONS

Combined early oral healthcare and early mobilisation by a multidisciplinary team significantly decreased the stroke-associated pneumonia incidence within 7 days and reduced the percentage of patients who died or required medical care because of recurrent pneumonia after stroke.

Spectroscopic Quantitative Measurement of the Cartilage Surface using Arthroscopy Correlates with a Conventional Macroscopic Grading System

Purpose

To quantify the cartilage surface profile visualized during arthroscopic surgery and examine its clinical utility by comparing the results of quantitative measurements with a conventional grading system.

Methods

Fifty consecutive patients diagnosed with knee osteoarthritis and who underwent arthroscopic surgery were included in this study. A 4 K camera system was used, and the cartilage surface profile was visualized using the augmented reality imaging program. The highlighted image was displayed in 2 colors: black (the worn cartilage area) and green (the part where the cartilage thickness was maintained). The percentage of the green area was calculated using ImageJ and used as an index of cartilage degeneration. The quantitative value was statistically compared with the International Cartilage Repair Society (ICRS) grade as a conventional macroscopic evaluation.

Results

In the quantitative measurement, the median percentage of the green area was 60.7 at ICRS grades 0 and 1 (interquartile range [IQR], 67.3-51.0), 47.2 at grade 2 (IQR, 54.1-39.2), 36.5 at grade 3 (IQR, 43.2-30.4), and 34.0 at grade 4 (IQR, 38.5-29.3). There was a significant difference between the macroscopic grades, except for Grades 3 and 4. There was a significant negative correlation between macroscopic evaluation and quantitative measurement (r = -0.672, P < .001).

Conclusions

The quantitative measurement of the cartilage surface profile using the spectroscopic absorption technique was significantly correlated with the conventional macroscopic grading system and demonstrated fair to good inter-rater and intra-rater reliabilities.

Level of Evidence

Level II, diagnostic (prospective cohort study).

Effusion detected by ultrasonography and overweight may predict the risk of knee osteoarthritis in females with early knee osteoarthritis: a retrospective analysis of Iwaki cohort data

BACKGROUND

Knee osteoarthritis (OA) has enormous medical and socioeconomic burdens, which early diagnosis and intervention can reduce. We investigated the influence of knee effusion on the progression of knee OA in patients with early knee OA.

METHODS

A total of 404 participants without radiographic knee OA were assessed from a 3-year longitudinal analysis. Participants were classified into non-OA and early knee OA groups. The effusion area (mm²) was quantified using ultrasonography. Receiver operating characteristic and logistic regression analyses were performed.

RESULTS

At the 3-year follow-up, 114 of 349 knees (32%) had progressed from non-OA and 32 of 55 knees (58%) had progressed from early knee OA to radiographic knee OA. Logistic regression analysis showed that female sex (odds ratio [OR] 3.36, 95% confidence interval [CIs] 2.98-5.42), early knee OA (OR 2.02, 95% CI 1.08-3.75), body mass index (OR 1.11, 95% CI 1.02-1.19), and effusion area (OR 1.01, 95% CI 1.01-1.02) were significantly correlated with knee OA progression. Women who were overweight (body mass index ≥ 25 kg/m²) with more severe effusion had a higher risk of OA progression (area under the curve = 0.691, OR = 6.00) compared to those not overweight (area under the curve = 0.568, OR = 1.91).

CONCLUSION

Knee effusion may be an indicator of the progression of early-stage knee OA.

Clinical outcomes of medial patellofemoral ligament reconstruction using FiberTape and knotless SwiveLock anchors

BACKGROUND

We aimed to prospectively investigate the clinical outcomes of medial patellofemoral ligament (MPFL) reconstruction using polyester high-strength suture tape with knotless anchors.

METHOD

Forty-three patients (65 knees) were followed for at least 1 year postoperatively, with 27 patients (43 knees) followed for 2 years postoperatively. All patients underwent MPFL reconstruction using polyester high-strength suture tape (FiberTape®; Arthrex) with knotless anchors (SwiveLock®; Arthrex). Repeated dislocation and residual patellar apprehension signs were recorded, and congruence and tilting angles were measured. Changes in Knee Injury and Osteoarthritis Outcome Scale (KOOS) scores and their associations with the preoperative tibial tubercle-trochlear groove (TT-TG) distance were analyzed.

RESULTS

No repeat dislocations (0%) were observed. One (2.4%) residual positive patellar apprehension sign was noted. The mean tilting angle decreased from 24.8° to 10.7° (P < 0.001), and the mean congruence angle decreased from 24.9° to 4.3° (P < 0.001). At 2 years follow up, all KOOS subscales had improved: pain (92.0 ± 12.9), symptoms (90.2 ± 11.9), activities of daily living (95.7 ± 7.3), sports activity (85.7 ± 16.9), quality of life (87.7 ± 12.9), and patellofemoral (89.0 ± 9.6) outcomes. KOOS subscale scores improved regardless of the preoperative TT-TG distance (21.1 ± 3.5 mm; range, 13.8-29.9 mm).

CONCLUSIONS

MPFL reconstruction using FiberTape and knotless SwiveLock anchors was performed without sacrificing autologous tissue. No recurrent patellar dislocation was observed during the 2-year follow up period. All KOOS subscale scores improved using FiberTape and SwiveLock anchors in MPFL reconstruction.

Association Between Early Postoperative Graft Signal Intensity and Residual Knee Laxity After Anterior Cruciate Ligament Reconstruction

Background:

Magnetic resonance imaging (MRI) graft signal intensity is associated with graft damage after anterior cruciate ligament reconstruction (ACLR). However, little is known about the relationship between graft signal intensity and residual laxity of the reconstructed knee based on patient age.

Purpose/Hypothesis:

To evaluate the relationship between graft signal intensity and residual laxity in younger and older patients who underwent ACLR. We hypothesized that higher graft signal intensity would be associated with reduced postoperative knee stability.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A total of 192 patients who underwent double-bundle ACLR were recruited. Proton density–weighted and T2-weighted MRI was performed at 3, 6, and 12 months after surgery, and the signal intensity ratio (SIR) of the anteromedial and posterolateral bundles was measured as the graft signal intensity reference values. At 12 months after surgery, if the KT-1000 arthrometer measurement exhibited a side-to-side difference of ≥2 mm, the patient was determined as having anterior knee laxity. Rotatory knee laxity was defined as a positive pivot shift with International Knee Documentation Committee grade ≥1. The Mann-Whitney U test was used to compare the SIR in patients with and without residual laxity. The Spearman correlation coefficient was used to evaluate the relationship between demographic parameters and the SIR. Based on receiver operating characteristic curves, the optimal SIR cutoff values to predict residual laxity were calculated, and logistic regression analysis was conducted.

Results:

Of 192 patients, 26 (13.5%) had anterior knee laxity, and 20 (10.4%) had rotatory knee laxity. The SIR was negatively correlated with age. In younger patients (<30 years; n = 135), those with residual laxity had a significantly higher SIR than those without laxity; this relationship was not significant in older patients (≥30 years; n = 57). Based on receiver operating characteristic curves and logistic regression analysis, the cutoff values that were determined for the SIR were significantly associated with a higher odds ratio of residual laxity.

Conclusion:

Graft signal intensity decreased with patient age. Patients with higher graft signal intensity in the early postoperative phase after ACLR exhibited a higher prevalence of residual laxity, particularly in younger patients.

Influence of hamstring tendon and bone-patellar tendon-bone autografts on worsened patient reported outcome measurements in revision anterior cruciate ligament reconstruction: Comparing outcomes between primary and revision reconstructions

Background

This study aimed to compare the clinical outcomes and patient reported outcome measurement scales (PROMs) between hamstring tendon (HT) or bone-patellar tendon-bone (BTB) grafts in each primary and revision anterior cruciate ligament (ACL) reconstruction. Additionally, the clinical outcomes and PROMs between primary and revision surgeries were compared.

Methods

A total of 150 patients (109 primary and 41 revision ACL reconstructions) were enrolled and followed up for an average of 3.9 years (2 years minimum). Knee injury and osteoarthritis outcome scores (KOOS) were examined as PROMs. Side-to-side differences of anterior knee laxity were assessed using KT-1000 and were recorded at the final follow-up. After categorizing patients into HT and BTB reconstruction groups, regression analysis was performed to determine the relationship between revision surgery and changes in KOOS.

Results

In patients who underwent primary surgery, there was no significant difference in side-to-side differences of anterior laxity and KOOS between HT and BTB grafts. In those who underwent revision surgery, BTB grafts had a higher KOOS for activities of daily living (ADL) than HT grafts (p = 0.032). Comparing primary and revision surgeries, postoperative side-to-side differences of anterior laxity in the revision group were significantly larger than those in the primary group (p = 0.001). The KOOS for sports after overall revision reconstruction was significantly lower than that after primary reconstruction (p = 0.026). Comparing the KOOS after dividing all patients into HT and BTB reconstruction groups, in the HT reconstruction group, postoperative KOOS results were not different in any subscale from BTB grafts. In contrast, the KOOS for sports (p = 0.008) and QOL (p = 0.039) were significantly lower in revision surgery than in primary surgery. Furthermore, regression analysis including multiple confounders in the HT reconstruction group showed revision surgery using HT graft was correlated with worsened KOOS for symptoms (p = 0.012) and sports (p = 0.010). Revision surgery using BTB graft was not correlated with decreased KOOS.

Conclusions

There were no differences between the clinical outcome and KOOS in primary and revision surgery, except for ADL scores following revision ACL reconstruction using BTB graft. Side-to-side difference of anterior laxity and KOOS for sports following revision ACL reconstruction were inferior to those following primary ACL reconstruction.

Furthermore, revision ACL reconstruction using HT grafts were correlated with low scores in KOOS for symptoms and sports, while there was no difference of anterior laxity between BTB and HT grafts in revision surgery.

Metabolomics with severity of radiographic knee osteoarthritis and early phase synovitis in middle-aged women from the Iwaki Health Promotion Project: a cross-sectional study

Background

Osteoarthritis (OA) is one of the costliest and most disabling forms of arthritis, and it poses a major public health burden; however, its detailed etiology, pathophysiology, and metabolism remain unclear. Therefore, the purpose of this study was to investigate the key plasma metabolites and metabolic pathways, especially focusing on radiographic OA severity and synovitis, from a large sample cohort study.

Methods

We recruited 596 female volunteers who participated in the Iwaki Health Promotion Project in 2017. Standing anterior-posterior radiographs of the knee were classified by the Kellgren-Lawrence (KL) grade. Radiographic OA was defined as a KL grade of ≥ 2. Individual effusion-synovitis was scored according to the Whole-Organ Magnetic Resonance Imaging Scoring System. Blood samples were collected, and metabolites were extracted from the plasma. Metabolome analysis was performed using capillary electrophoresis time-of-flight mass spectrometry. To investigate the relationships among metabolites, the KL grade, and effusion-synovitis scores, partial least squares with rank order of groups (PLS-ROG) analyses were performed.

Results

Among the 82 metabolites examined in this assay, PLS-ROG analysis identified 42 metabolites that correlated with OA severity. A subsequent metabolite set enrichment analysis using the significant metabolites showed the urea cycle and tricarboxylic acid cycle as key metabolic pathways. Moreover, further PLS-ROG analysis identified cystine (p = 0.009), uric acid (p = 0.024), and tyrosine (p = 0.048) as common metabolites associated with both OA severity and effusion-synovitis. Receiver operating characteristic analyses showed that cystine levels were moderately associated with radiographic OA (p < 0.001, area under the curve 0.714, odds ratio 3.7).

Conclusion

Large sample metabolome analyses revealed that cystine, an amino acid associated with antioxidant activity and glutamate homeostasis, might be a potential metabolic biomarker for radiographic osteoarthritis and early phase synovitis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02830-w.

Prevalence of Segond fractures associated with anterior cruciate ligament injuries and their influence on knee joint stability; A case-control study

Background

The purpose of this study was to determine the prevalence of Segond fractures and to compare knee stability between patients undergoing primary anterior cruciate ligament (ACL) reconstruction with and without Segond fractures pre- and postoperatively.

Methods

A total of 712 patients who underwent primary ACL reconstruction between 2014 and 2019. Exclusion criteria included patients with multi-ligament knee injuries, skeletally immature patients, osteoarthritis in the knee, combined surgery of high tibial osteotomy, lack of data, and loss to follow-up for at least 2 years. Segond fractures were confirmed using plain radiography, computed tomography (CT), and magnetic resonance imaging (MRI). Patients with Segond fractures were classified into Group S and without Segond fractures into Group N. Pre- and postoperative Lachman grades, pivot-shift grades, and assessment of side-to-side differences in anterior stability were evaluated.

Results

Five hundred and forty patients included in this study. There were 22 patients with Segond fractures. Of these, all 22 cases (4.1%) were identified on CT, but only 20 cases (3.7%) were identified on MRI and 18 cases (3.3%) on plain radiographs. There was no significant difference in preoperative Lachman grade or pivot-shift grade between Groups S and N (p = 0.662, p = 0.677, respectively). There was no significant difference in postoperative Lachman grade or pivot-shift grade between Groups S and N (p = 0.685, p = 0.390, respectively). There were no significant differences in preoperative (p = 0.398) or postoperative (p = 0.546) side-to-side differences of anterior stability between Groups S and N.

Conclusions

Segond fractures were confirmed in 4.1% of the cases on CT scans among patients undergoing primary ACL reconstruction. Segond fractures did not affect preoperative or 2-year follow-up evaluations of knee stability. From these results, we concluded that Segond fractures did not affect the clinical outcomes of the primary ACL reconstruction and that it may not be necessary to treat Segond fractures.

Bone marrow lesion severity was associated with proximal tibial inclination in early knee osteoarthritis

PURPOSE

This study aimed to investigate the effect of tibial plateau (TP) inclination and serum bone metabolic markers on bone marrow lesion (BML) in the general Japanese population with early knee osteoarthritis (EKOA).

METHODS

A total of 441 female volunteers who participated in the Iwaki Health Promotion Project in 2017 were enrolled. Participants without radiographic abnormalities were divided into normal and EKOA groups according to the Luyten's classification criteria for EKOA. The medial proximal tibial angle (MPTA), growth plate-TP angle, and growth plate-medial tibial plateau (MTP) angle were measured on standing anteroposterior radiographs of the knees. BML severity on T2-weighted fat-suppressed magnetic resonance imaging (MRI) was scored using the Whole-Organ MRI Score method. Serum levels of N-telopeptide of type I collagen, tartrate-resistant acid phosphatase-5b (TRACP-5b), bone-specific alkaline phosphatase, procollagen type I N-terminal propeptide, pentosidine, and homocysteine were assessed. Linear regression analysis was conducted to investigate the relationship between proximal tibial inclination, BML, and serum bone metabolic markers.

RESULTS

The growth plate was observed in 309 (70%) participants, and 48 (16%) participants had EKOA. The mean MPTA, growth plate-TP angle, and growth plate-MTP angle were 86.1 ± 5.9°, 3.6 ± 1.1°, and 9.9 ± 2.6°, respectively. The MPTA was negatively correlated with the growth plate-TP and growth plate-MTP angles (p = 0.006, p < 0.001). Participants with EKOA who had BML exhibited greater growth plate-MTP angle than those who did not (p = 0.018). Regression analysis revealed that BML severity was positively associated with MPTA (p = 0.036) and a bone formation marker (p = 0.045).

CONCLUSION

BML severity was positively associated with proximal tibial inclination and serum TRACP-5b level in participants with EKOA and normal knees, respectively. Assessment of proximal tibial inclination may provide insight into potential BML risk. Residual medial tibial inclination may potentially result in knee pain and symptoms in EKOA.

LEVEL OF EVIDENCE

III.

Biomechanical analysis of bioabsorbable suture anchors for rotator cuff repair using osteoporotic and normal bone models

BACKGROUND

This study aimed to compare the failure load of suture anchors used in rotator cuff repair between normal and osteoporotic bone models.

METHODS

A total of 16 anchors made from metal (TwinFix Ti 5.0 or 6.5 mm, Corkscrew FT 4.5, 5.5, or 6.5 mm), polyether ether ketone (HEALICOIL PK [HC-PK] 4.5 or 5.5 mm, SwiveLock PK 4.75 or 5.5 mm), or bioabsorbable material (HEALICOIL RG [HC-RG] 4.75 or 5.5 mm, Corkscrew Bio 4.75, 5.5, or 6.5 mm, SwiveLock BC 4.75 or 5.5 mm) were included. Moreover, 10- and 5-pounds per cubic foot (pcf) Sawbone® models were set as normal and osteoporotic cancellous bone models, respectively. Pullout testing was performed in parallel to the insertion axis at a displacement rate of 12.5 mm/s using a universal testing machine. To evaluate the change in failure load between the two Sawbone® models with different densities, the remaining failure load ratio (RFLR) was defined as the ratio of the failure load in 10 pcf to that in 5 pcf.

RESULTS

In the 10-pcf Sawbone®, TwinFix Ti 6.5 mm showed the highest mean failure load (304.0 ± 15.2 N). In the 5-pcf Sawbone® model, HC-PK 5.5 mm showed the highest failure load (146.3 ± 5.8 N). Among anchors with the same diameter, HC-PK and HC-RG showed a significantly higher failure load than other anchors in the 10- and 5-pcf Sawbone® models. HC-PK 5.5 mm (62.1%) and HC-PK 4.5 mm (51.1%) have the highest RFLR among anchors with the same diameter.

CONCLUSIONS

HC-PK and HC-RG showed higher failure load than the other anchors in both normal and osteoporotic bone models, except for TwinFix Ti 6.5 mm in the 10-pcf Sawbone® model. Based on our results, bioabsorbable anchors had sufficient failure load for rotator cuff repair in addition to bioabsorbability.

Central Sensitization and Postoperative Improvement of Quality of Life in Total Knee and Total Hip Arthroplasty: A Prospective Observational Study

Background:

While total knee arthroplasty (TKA) and total hip arthroplasty (THA) lead to excellent clinical outcomes, some patients experience residual surgical site pain and reduced satisfaction. This prospective observational study investigated the prevalence of preoperative and postoperative residual central sensitization (CS) after TKA and THA. The influence of residual CS on the improvement in quality of life (QOL) was also investigated.

Methods:

The participants were 40 patients who underwent TKA and 47 patients who underwent THA. CS was measured using the central sensitization inventory (CSI) questionnaire. Knee symptoms were evaluated using the Knee Injury and Osteoarthritis Outcome Scales (KOOS), and hip symptoms were evaluated using the Japanese Orthopedic Association Hip-disease Evaluation Questionnaires (JHEQ). General QOL was evaluated using EuroQOL (EQ-5D-5l). Regression analysis was performed to estimate factors related to low QOL after surgery.

Results:

Preoperatively, 47.5% of TKA patients and 66.0% of THA patients were CS positive (P=0.083), which reduced to 10.0% (P=0.042) and 25.5% (P=0.202), respectively, 3 months after surgery. Although the improvements in KOOS subscales and EQ-5D-5l scores in TKA patients with residual CS were significantly lower than in those without residual CS, residual CS status had no effect on JHEQ subscales and EQ-5D-5l scores in THA patients. Regression analysis indicated that EQ-5D-5l was negatively correlated with CSI in the TKA group (P=0.017). In contrast, CSI was not correlated with EQ-5D-5l in the THA group (P=0.206).

Conclusion:

Postoperative QOL improvement was achieved 3 months after THA regardless of residual CS status. In contrast, preoperative CS was negatively associated with the improvement in QOL after TKA.

Laterally shifted tibial tunnel can be the risk of residual knee laxity for double-bundle anterior cruciate ligament reconstruction

PURPOSE

To elucidate the relationship between graft tunnel position and knee laxity in the cases of double-bundle ACL reconstruction.

METHODS

Total of 132 cases were included. Femoral and tibial tunnels were evaluated by quadrant method on 3D-CT. As additional reference of tibia, the distances from medial tibial spine to the tunnel center (D_MS) and from Parsons' knob to the tunnel center (D_PK) were evaluated; %D_MS/ML and %D_PK/AP were calculated (ML and AP: mediolateral and anteroposterior width of tibial plateau). Preoperative and postoperative (1 year from surgery) stabilities were evaluated by Lachman and pivot-shift procedures. If there was ≥ 2 mm side-to-side difference, the subject was defined as having anterior knee laxity (AKL); if the pivot-shift phenomenon was observed with IKDC grade ≥ 1, there was rotatory knee laxity (RKL). Multiple logistic regression analysis was conducted with the prevalence of AKL or RKL as the dependent variable and with tunnel positions as the independent variables.

RESULTS

Overall, 21 subjects (15.9%) showed AKL, and 15 subjects (11.4%) showed RKL. Those with postoperative laxity showed higher %D_MS/ML and higher femoral position than those without laxity. Regarding posterolateral bundle, logistic regression model estimated that %D_MS/ML was associated with the prevalence of AKL (B = 0.608; p < 0.001) and RKL (B = 0.789; p < 0.001); %high-low femoral tunnel position (B =  - 0.127; p = 0.023) was associated with that of RKL.

CONCLUSION

There was the risk of residual knee laxity in ACL-reconstructed knee when tibial tunnel shifted more laterally or higher femoral tunnel was created with regard to posterolateral bundle.

LEVEL OF EVIDENCE

III.

Early Return to Sports to Continue the Season after Anterior Cruciate Ligament Injury Is Not Recommended for Student Athletes

Objective:

The objectives of this study were to investigate whether student athletes with anterior cruciate ligament (ACL) injuries who returned to sports (RTS) without reconstruction could continue their sporting activities until the end of the season and whether there was an increase in secondary damage associated with knee instability.

Methods:

Altogether, 288 skeletally mature patients aged <25 years with new-onset isolated primary ACL injuries were included. Of these, 20 student athletes continued playing sports without ACL reconstruction to try to finish the season and were classified as the early return to sports (ERS) group; the remaining 268 patients, who immediately quit sports and underwent surgery, were classified as the non-ERS group. Knee symptoms and sporting performance for the rest of the season were assessed for the ERS group. The presence of secondary damage, e.g., meniscus injuries and chondral lesions, associated with instability were compared between the two groups.

Results:

Fourteen ERS-group athletes (70%) indicated that their knees had given way during sporting activities, and seven athletes (35%) were unable to complete the season. In the ERS group, the mean self-estimated performance level after injury was 3.8 ± 2.5 (numeric rating scale 0–10). Despite the RTS period being relatively short, medial meniscus tears (P <0.001) significantly increased in the ERS group, and three patients experienced locking of the medial meniscus and required immediate surgery.

Conclusions:

Although ERS without reconstruction to complete the season may be a reasonable strategy for ACL injury, patients’ self-estimated performance level was low and meniscal and cartilage injury rates significantly increased.

Meniscus Allograft Transplantation Obtained From Adult Patients Undergoing Total Knee Arthroplasty May be Used for Younger Patients After Lateral Discoid Meniscus Meniscectomy

Purpose

To investigate the clinical outcomes following meniscus allograft transplantation (MAT) to replace removed discoid lateral meniscus using intact lateral meniscus obtained from patients undergoing total knee arthroplasty for medial compartment osteoarthritis.

Methods

Pediatric patients who underwent MAT secondary to partial or total meniscectomy due to discoid lateral meniscus between August 2010 and November 2018 were identified. Lateral menisci with bone blocks were transplanted arthroscopically. The demographic data, range of motion, meniscal allograft failure, which was defined as removal of an implanted meniscus, and complications were recorded. The Lysholm score and the Kellgren-Lawrence (KL) grade on radiographs were evaluated preoperatively and at final follow-up. The Knee injury and Osteoarthritis Outcome Score was evaluated in the final follow-up.

Results

Eight patients who were symptomatic after discoid lateral meniscectomy were included. Donated allografts were harvested from adult patients aged between 64 and 78 years (mean 70.5 years). The mean age at previous meniscectomy and MAT were 10.5 and 18.1 years, respectively. All patients were followed up for a mean time of 5.2 years, and there were no cases of meniscus failure and complication. The Lysholm score significantly improved from preoperative to the final follow-up. Preoperatively, 6 and 2 knees were of KL grades II and III, respectively. At final follow-up, no increased KL grade was observed in 5 patients; however, an increase by 1 grade was observed in 2 patients and an increase by 2 grades was observed in 1 patient. The Knee injury and Osteoarthritis Outcome Scores at the final follow-up were 87.2 for pain, 87.9 for symptoms, 95.4 for activities of daily living, 79.4 for sports, and 65.6 for quality of life.

Conclusions

Older lateral meniscus allografts obtained from knees of adult patients undergoing total knee arthroplasty and transplanted into younger patients with defects from discoid lateral meniscectomy resulted in improved Lysholm scores but no improvement in Tegner scores or knee motion. KL grades were unchanged in 5 of the 8 patients at the final follow-up.

Level of Evidence

IV, therapeutic case series.

Clinical Outcomes and Postoperative Complications After All-Epiphyseal Double-Bundle ACL Reconstruction for Skeletally Immature Patients

Background

The treatment strategy for pediatric anterior cruciate ligament (ACL) tears, especially in patients with open physes, remains controversial.

Purpose

To assess clinical outcomes and postoperative complications after all-epiphyseal double-bundle ACL (DB-ACL) reconstruction for patients with open physes.

Study Design

Cohort study; Level of evidence, 3.

Methods

Included were 102 patients aged ≤15 years who underwent ACL reconstruction at a single institution and had a minimum of 2 years of follow-up. Of these patients, 18 had undergone all-epiphyseal DB-ACL reconstruction (mean age, 12.4 ± 1.2 year) and 84 had undergone conventional DB-ACL reconstruction (mean age, 14.1 ± 0.9 year). The outcomes of the all-epiphyseal group were compared with those of the conventional group. Objective clinical outcomes included KT-1000 arthrometer measurements of side-to-side difference in anterior tibial translation, Lachman test grade, and pivot-shift test grade. Radiographic angular deformity (defined as >3° of the side-to-side difference in femorotibial angle) and incidence of second ACL injury were also compared.

Results

The postoperative side-to-side difference in laxity significantly improved from 6.1 ± 2.4 to 0.6 ± 0.9 mm in the all-epiphyseal group (P = .001), and postoperative laxity was similar to that of the conventional group (0.4 ± 0.8 mm; P = .518). A Lachman grade 1 positive result was observed in 20% of the all-epiphyseal group and 3% of the conventional group (P = .042), and a pivot-shift grade 1 positive result was observed in 22% of the all-epiphyseal group and 4% of the conventional group (P = .074). A total of 4 patients (26.7%) in the all-epiphyseal group and 4 (6.1%) in the conventional group demonstrated angular deformity (P = .035). The incidence of postoperative ipsilateral ACL tear was 16.7% in the all-epiphyseal group and 23.8% in the conventional group (P = .757). The incidence of contralateral ACL tear was 11.1% in the all-epiphyseal group and 14.3% in the conventional group (P ≥ .999).

Conclusion

All-epiphyseal DB-ACL reconstruction for skeletally immature patients achieved satisfactory clinical outcomes compared with conventional DB-ACL reconstruction. The incidence of ipsilateral graft rupture was relatively high in both groups. The all-epiphyseal group had a significantly higher incidence of angular deformity.

Association Between Central Sensitization and Increasing Prevalence of Nocturnal Knee Pain in the General Population with Osteoarthritis from the Iwaki Cohort Study

Purpose

Knee pain is associated with osteoarthritis (OA) and increases during this condition; however, its correlation with central sensitization (CS) in arthritis patients requires greater understanding. The present cross-sectional cohort study to explore the prevalence of knee OA, nocturnal knee pain and disability in general population and to examine the association of CS with sleep quality in Japanese general population.

Patients and Methods

From among 1056 community-dowelling volunteers, 942 were enrolled as participants in this study. Bilateral weight-bearing anterior-posterior knee radiographs were classified by the Kellgren-Lawrence grade. Nocturnal knee pain and disability were assessed with self-reported questionnaires. Using the CS inventory with nine items (CSI-9), CS was defined as 10 points or higher. Sleep quality was scored using the Pittsburgh Sleep Quality Index (PSQI). Linear regression analysis, adjusted by age, sex, body mass index, Kellgren-Lawrence grade, nocturnal knee pain, and lifestyle habits, was performed to investigate the association of CS with PSQI.

Results

The prevalence of OA, nocturnal knee pain, and disability was 37.9%, 7.6%, and 6.2%, respectively. The mean CSI-9 score was 4.9 ± 4.4, with a CS prevalence of 14.0%. The mean PSQI score was 3.9 ± 2.4, which was correlated with the CSI-9 value. CS was not correlated with OA severity; however, nocturnal knee pain prevalence increased from 13.3% to 25.5% in knee OA patients with CS. The CSI-9 value correlated with PSQI total score and subscales.

Conclusion

Knee OA severity correlated with nocturnal pain and disability; however, its association with CS was unproven. The combined effect of knee OA and CS elevated nocturnal pain and disability, resulting in diminished sleep quality.

Treatment Efficacy of Single Topical NSAID (S-Flurbiprofen Plaster) for Knee Symptoms and Locomotive Dysfunction in Knee Osteoarthritis Patients

Objective:

The aim of this study was to demonstrate the non-inferiority of S-flurbiprofen plaster (SFPP) monotherapy for treating knee osteoarthritis compared with the combination of conventional oral and topical non-steroidal anti-inflammatory drugs (NSAIDs).

Methods:

A total of 222 participants (114, SFPP group; 108, control group) were treated for 4 weeks. The primary endpoint was the change in the degree of pain felt while rising from a chair after 2 and 4 weeks of treatment as determined using the visual analog scale (VAS) . The secondary endpoint was the change in functional scores and test results. Safety was evaluated in terms of the adverse effects.

Results:

The VAS score significantly decreased in both groups after 2 and 4 weeks of treatment. Non-inferiority in the VAS score was established only at 2 weeks. There were no significant differences in the secondary endpoints between the groups. Skin disorders were more frequent in the SFPP group; however, there was no difference in gastrointestinal (GI) adverse effects.

Conclusions:

The therapeutic efficacy of SFPP monotherapy for knee OA, with respect to changes in the VAS, was not shown to be non-inferior to conventional treatment at 4 weeks; however, non-inferiority was established at 2 weeks. The functional improvement in the SFPP group was comparable to that of the control group. No severe GI adverse effects associated with SFPP administration were observed; however, it is necessary to pay more attention to the occurrence of skin disorders with SFPP than with conventional topical NSAIDs.

Effect of gait training using Hybrid Assistive Limb on gait ability and the risk for overwork weakness in the lower limb muscles in patients with neuromuscular diseases: a proof-of-concept study

BACKGROUND

Few previous studies have reported the efficacy of robot rehabilitation for improving gait ability or its adverse events in patients with neuromuscular diseases.

AIM

The aim of the present study was to elucidate the effects of gait training with a hybrid assistive limb (HAL) on gait ability and to investigate serum enzyme levels associated with skeletal muscle damage.

DESIGN

a proof-of-concept study.

POPULATION

Twenty-one patients with neuromuscular disease (13 males and 8 females, mean age of 60.6 years).

SETTING

Department of rehabilitation medicine in university hospital.

METHODS

All patients underwent 1 to 7 series of gait rehabilitation which consisted of 9 sessions of HAL training. Gait ability was assessed with the 10-meter walk test and the 2-min walk test before and after HAL training, while serum creatine phosphokinase, aspartate aminotransferase, and lactic acid dehydrogenase values were measured before, midway through, and after HAL training.

RESULTS

Gait velocity and step length for 10-meter walk test, and 2-min walk distance were significantly improved after HAL gait training. There was no significant change in serum level of all 3 measured enzymes between the three time points.

CONCLUSIONS

HAL gait training with the practical setting as this study improved gait ability in patients with progressive neuromuscular disease and did not damage skeletal muscle, as indicated by no significant change in serum level of muscle enzymes.

CLINICAL REHABILITATION IMPACT

Robot assisted gait training could be safely applied to the patients with neuromuscular diseases, as one of the effective rehabilitation programs to improve gait ability.

Effects of gait training with a voluntary-driven wearable cyborg, Hybrid Assistive Limb (HAL), on quality of life in patients with neuromuscular disease, able to walk independently with aids

Robot-assisted gait training using a voluntary-driven wearable cyborg, Hybrid Assistive Limb (HAL), has been shown to improve the mobility of patients with neurological disorders; however, its effect on the quality of life (QOL) of patients is not clear. The aim of this study was to assess the effects of HAL-assisted gait training on QOL and mobility in patients with neuromuscular diseases (NMDs). Ten patients with NMDs (seven men and three women, mean age: 57 ± 11 years), with impairment in mobility but could walk alone with aids underwent two courses of gait training with HAL over 6 months, and the single course consisted of nine sessions of training for 4 weeks. We compared the findings of the 2 min walk test, 10 m walk test, the Short Form-36 (SF-36) questionnaire, and the Hospital Anxiety and Depression Scale at baseline, after the 1st training, before the 2nd training, and after the 2nd training using the Friedman test. A significant improvement was observed in the 2 min walking distance from baseline (93 ± 50 m) to after the 2nd training (115 ± 48 m, P = 0.034), as well as in the domains of vitality (P = 0.019) and mental component summary score (P = 0.019) of SF-36. The improvement in 10 m walking speed was significantly correlated with that in the physical functioning (R = 0.831, P = 0.003) and role physical (R = 0.697, P = 0.025) domains in the SF-36. Our findings suggest that HAL-assisted gait training is effective in improving QOL associated with mental health as well as gait ability in selected patients with NMDs.

Effect of a simple core muscle training program on trunk muscle strength and neuromuscular control among pediatric soccer players

Purpose

The purpose of this study was to examine the effect of simple core muscle training (CMT) program on trunk muscle strength and neuromuscular control among pediatric athletes.

Methods

Forty-nine male soccer players (mean age, 10.8 years) participated. The CMT program had three components (bench, side bench, and Nordic hamstrings) and was performed at least three times weekly for a year. Trunk flexion/extension muscle strength and the K/H ratio (determined by dividing knee separation distance by hip separation distance during drop-jump test and used as an index of lower limb valgus alignment) were measured, and the Y balance test (YBT) was performed before and after intervention. This study did not include the pure control group among the same team. To consider the effect of CMT on trunk muscle strength due to physical growth, we used the data of trunk muscle strength from the local cohort study previously conducted in our institution. One hundred participants who matched the age, height, body weight, and body mass index of the training group was designated as a control group.

Results

In the training group, the trunk flexion/extension strength significantly increased at 6 months (p < 0.001, p < 0.001, respectively) and 12 months (p < 0.001, p < 0.001, respectively) compared to initial value. The K/H ratio at initial contact and maximum knee flexion phase significantly increased at 6 months (p < 0.001 and p < 0.001, respectively); however, it did not increase at 12 months (p = 0.384 and p = 0.070, respectively) compared to the initial value. In the YBT, the maximized reach distance in each direction significantly increased after intervention on both the dominant and non-dominant sides, except in the posteromedial direction on the non-dominant foot. Compared to the control group, although there was no significant difference in trunk flexion/extension strength at baseline (p = 0.141 and p = 0.390, respectively), the training group showed significantly higher trunk flexion/extension muscle strength at 12 months (p < 0.001 and p < 0.001, respectively).

Conclusion

The CMT program increased trunk muscle strength and improved dynamic balance among pediatric male athletes.

Level of evidence

Level II

Clinical Outcomes and Medical Costs of Hydration Therapy with Hydroxyethyl Starch (130/0.4) or Acute Single Infarction

OBJECTIVES

To investigate the effects of hydration with or without Hydroxyethyl Starch (HES) 130/0.4 on neurological outcomes and medical costs during hospitalisation in patients with a single infarction (SI) in the posterior lenticulostriate artery (LSA) territory.

MATERIALS AND METHODS

In this retrospective, single-centre, non-blinded cohort study, SI in the posterior LSA was defined as an ischaemic lesion with a high-signal intensity area ≥20 mm. All patients received basic stroke care within 48 h of symptom onset between April 2015 and January 2019. Patients were divided into the following two groups by clinician's preference: 1) those administered HES 130/0.4 and 2) those receiving other infusion fluid. The relationships between hospital costs and hydration therapy type were examined.

RESULTS

Eighteen (31%) of 58 patients received HES 130/0.4. The HES group had a significantly lower total cost than the control group (3.6 vs. 6.4 million yen, p=0.006). Moreover, the HES group had a significantly shorter hospital stay duration (79.5 vs. 141.0 days) and lower National Institutes of Health Stroke Scale score on day 7. Multivariate analysis found that HES 130/0.4 administration was an independent factor associated with high costs.

CONCLUSIONS

Hydration therapy with HES 130/0.4 significantly decreased the total costs and hospitalisation duration of patients with SI in the posterior LSA territory.

Incidence and Risk Factors of Subsequent Meniscal Surgery After Successful Anterior Cruciate Ligament Reconstruction: A Retrospective Study With a Minimum 2-Year Follow-up

BACKGROUND

One of the goals of anterior cruciate ligament (ACL) reconstruction is a meniscal protective effect on the knee. Despite the advancement of ACL reconstruction techniques, subsequent meniscal tears after ACL reconstruction remain a problem, and the risk factors for recurring lesions are still unclear.

PURPOSE

To investigate the incidence of subsequent meniscal surgery after primary ACL reconstruction without revision ACL surgery and to determine the risk factors associated with this reoperation.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Overall, 518 patients who underwent primary ACL reconstruction between 2004 and 2012 at one instution participated in this study. Data on body mass index, graft type and femoral tunnel-drilling technique of ACL reconstruction, and location and type of meniscal injury and its treatment at ACL reconstruction were collected from medical records. Clinical outcomes were investigated, including side-to-side difference of anterior laxity, pivot-shift grade, and subsequent meniscal surgery without ACL insufficiency (at minimum 2-year follow-up).

RESULTS

The prevalence of tears to the medial meniscus (MM) at the primary ACL reconstruction was 43.6% (226/518), 140 of which were repaired; on the contrary, tears of the lateral meniscus (LM) had a prevalence of 55.8% (289/518), 42 of which were repaired. At a mean 30.3 months (range, 8-124 months) after ACL reconstruction, 20 patients (3.9%; 14 MM tears, 3 LM tears, 3 MM + LM tears) required meniscal surgery without ACL reinjury or recurrence of instability. Of these, 14 MMs and 3 LMs had been repaired at primary ACL reconstruction. The failure rates of repaired MM and LM were 10.0% (14/140) and 7.1% (3/42), respectively. The failure rate of MM repair using the all-inside technique (6/36) was significantly higher compared with no treatment, inside-out repair, or partial resection (P = .045). In multiple regression analysis, the presence of MM injury at the time of ACL reconstruction (odds ratio [OR], 7.81; P = .003), the side-to-side difference of postoperative anterior tibial translation (OR, 1.91; P = .032), and follow-up period after ACL reconstruction (OR, 1.02; P = .003) were risk factors of subsequent meniscal surgery after ACL reconstruction.

CONCLUSION

Incidence of subsequent meniscal surgery after successful ACL reconstruction was <5%. Presence of MM tear at the time of ACL reconsturuction, small amount of increased anterior laxity, and long-term period after ACL reconstruction were predictive of subsequent meniscal surgery.

Effects of the tibial tunnel position on knee joint stability and meniscal contact pressure after double-bundle anterior cruciate ligament reconstruction

BACKGROUND

To investigate the effect of the tibial tunnel position on knee stability and the maximum contact area and peak contact pressure on the menisci after double-bundle anterior cruciate ligament (ACL) reconstruction.

METHODS

Ten human knee specimens (mean age: 74.1 ± 15.8 years) were used in this study. The anterior tibial loading test was conducted using a material testing machine at 30°, 60°, and 90° of knee flexion, with the anterior tibial translation (ATT) and the maximum contact area and peak contact pressure on the menisci measured. Outcome measures were compared between the following groups: 1) intact ACL (intact group); 2) anatomical tibial tunnel position (anatomical group) and 3) posterior tibial tunnel position (posterior group) with double-bundle reconstruction, and 4) ACL-deficient (deficient group).

RESULTS

In response to a 100 N anterior tibial load, the ATT was greater for the posterior and ACL-deficient groups compared to that in the intact group. The normalized maximum contact area of the medial meniscus significantly decreased for the posterior group compared to that in the intact group. The normalized peak contact pressure on the medial meniscus increased in all groups compared to that in the intact group, but with no between-group differences in pressure applied to the lateral meniscus.

CONCLUSIONS

ATT and contact pressure on the medial meniscus increased, concomitant with a decrease in contact area of the medial meniscus, as the position of the tibial tunnel position moved towards a posterior position.

Acute primary repair of extraarticular ligaments and staged surgery in multiple ligament knee injuries

Background

The purpose of this study is to compare the outcomes of acute primary repair of extraarticular ligaments with staged surgery for acute knee dislocations (KDs) and multiligament knee injuries (MLKIs).

Materials and methods

Between January 2005 and May 2018, 61 consecutive patients diagnosed with MLKI or KD were referred to or visited our institution. Of these, 31 patients who underwent acute repair of extraarticular ligaments within 3 weeks of injury were included in this study. These patients were retrospectively classified into two groups: those who underwent only primary repair (repair group) and those who underwent staged reconstructive surgery (staged group). Follow-up examination included range of motion (ROM), knee joint stability (Lachman test, posterior drawer test, and varus and valgus stress test), Lysholm knee score, Tegner activity scale, and Knee Injury and Osteoarthritis and Outcome Score (KOOS).

Results

Twelve of the 31 patients did not need or desire further surgery and were included in the repair group. No significant difference was observed in demographic data between the repair and staged groups. Although staged surgery decreased positive posterior drawer test results, no significant difference was observed between the two groups regarding ROM, other knee joint stability tests, Lysholm scores, Tegner scale, or KOOS.

Conclusions

In this series, all patients returned to their activities of daily living and preinjury occupation levels. Acute primary repair of extraarticular ligaments provides essential knee stability without varus/valgus instability and may reduce the need for subsequent cruciate ligament reconstruction.

Level of evidence

Level IV, retrospective observational study.

Medial Patellofemoral Ligament Reconstruction Using FiberTape and Knotless SwiveLock Anchors

Medial patellofemoral ligament (MPFL) reconstruction usually involves hamstring autografts and is associated with donor-site morbidity. Excellent short-term results with MPFL reconstruction using synthetic materials have been reported. Although synthetics do not sacrifice autologous tissues, their material properties are significantly different from those of biological tissues. Therefore, accurate surgical procedures are required to achieve excellent results. The purpose of this report was to describe our surgical method for MPFL reconstruction using FiberTape and knotless SwiveLock anchors.

Detection of synovitis in early knee osteoarthritis by MRI and serum biomarkers in Japanese general population

To investigate synovitis' influence on early knee osteoarthritis (EKOA) by serum biomarkers and magnetic resonance imaging (MRI) findings in Japanese women. We enrolled 255 women aged 30-70 without radiographic abnormalities (Kellgren-Lawrence grade ≥ 2). Knee injury, OA outcome scores (KOOS), clinical examinations, and standing radiograph were used for classification criteria of EKOA. Participants were classified into normal knee group and EKOA group. All participants underwent MRIs of their right knee. The amount of effusion-synovitis volume was quantified. We compared serum matrix metalloproteinases-3 levels (MMP-3), high-sensitivity C-reactive protein, interleukin-6, and adiponectin between the groups. The relationship between synovitis and EOKA was investigated using multiple linear regression. Fifty-four participants (21%) were classified as EKOA. Serum MMP-3 concentration and effusion-synovitis volume were higher in patients with EKOA (p = 0.025 and p = 0.001, respectively). Effusion-synovitis volume negatively correlated with all KOOS subscales and positively correlated with serum MMP-3 concentration. Serum MMP-3 concentration was associated with effusion-synovitis volume β = 0.60, p < 0.001). There was mildly active but definitive synovitis in EKOA. This was an observational study so that no conclusions can be drawn regarding cause-effect for synovitis and symptoms. Future studies should conduct follow-up of participants with synovitis to assess the progression of knee OA.

The effects of ball impact position on shoulder muscle activation during spiking in male volleyball players

Background

The ball impact position during spiking in volleyball may influence the pattern of activation of shoulder girdle muscles and, therefore, could be a significant risk factor for shoulder injury.

Methods

Activation of 10 muscles in the dominant shoulder was evaluated using surface electromyography (EMG) in 11 male volleyball players, during spiking in a static standing position, with the goal being to precisely control the specified ball impact positions, without a run-up or ball setting. The following 4 ball impact positions were evaluated: standard, posterior, medial, and lateral. The EMG amplitude, normalized to the maximal voluntary isometric contraction of the respective muscles, was compared for each phase of the spiking movement between the standard position and the other 3 different impact positions, using the Dunnett test.

Results

The following between-position differences were noted for the deltoid muscle: increased activation of the anterior deltoid during the acceleration phase for the posterior position (P = .041), increase in the posterior deltoid during the acceleration phase for the lateral position (P = .04), and increase in the middle deltoid during the deceleration phase for the lateral position (P = .005).

Conclusion

A posterior or lateral shift in the position of ball impact may cause an increase in the activity of the deltoid muscle that would cause a decrease in the centripetal force of the humeral head through the acceleration and deceleration phases. As such, neuromuscular exercises, combined with strengthening of the rotator cuff muscle, might reduce the risk of shoulder injury during performance of the volleyball spiking movement.

Differences between the Craig's test and computed tomography in measuring femoral anteversion in patients with anterior cruciate ligament injuries

[Purpose] This study aimed to compare the Craig’s test and computed tomography (CT) in measuring the femoral anteversion angle (FAA) in patients with anterior cruciate ligament (ACL) injuries. The relationship between the FAA measured on CT, and the range of axial rotation of the hip joint and muscle tightness around the hip joint was also investigated. [Participants and Methods] Twenty-six patients who received CT examination within 3 months after ACL reconstruction were enrolled in this study. The Craig’s test, internal and external rotation of the hip, the Ely test, Ober’s test, and FAA on the CT were assessed. [Results] The FAA on the Craig’s test and CT in female patients was 24.3 ± 3.9° and 23.0 ± 10.3°, respectively on the uninjured side and 25.0 ± 5.2° and 20.3 ± 11.2°, respectively on the injured side, indicating no significant correlation between the 2 measurement techniques. In contrast, the FAA on the CT was significantly correlated with the range of internal rotation of the hip, which was 40.5 ± 6.1° on the uninjured side and 37.8 ± 5.6° on the injured side. [Conclusion] The results suggest that measuring the internal hip rotation range rather than the Craig’s test, provides more reliable estimates of the magnitude of FAA, and may help to evaluate the risk of ACL injuries in female athletes.

Patellofemoral Contact Pressure for Medial Patellofemoral Ligament Reconstruction Using Suture Tape Varies With the Knee Flexion Angle: A Biomechanical Evaluation

PURPOSE

The purpose of this study was to evaluate the effect of the knee flexion angle during graft fixation on patellofemoral (PF) contact pressure in medial patellofemoral ligament (MPFL) reconstruction using polyester suture tape and knotless anchors.

METHODS

Nine human knees (mean age 74.9 ± 14.1 years) were used in this study. Polyester suture tape was fixed at the medial edge of the patella with two 3.5-mm knotless anchors, and then to the femur with a 4.75-mm knotless anchor at 4 different knee flexion angles (0°, 30°, 60°, and 90°). A pressure sensor was used to measure the maximum contact pressure (MCP) of the medial and lateral PF joints in the intact knee and in postreconstruction knees at each knee flexion angle (0°, 30°, 60°, and 90°). Each MCP was normalized to that of the intact knee. A statistical comparison was made between MCP in the intact and reconstructed knees.

RESULTS

The normalized MCP of the medial PF joint fixed at either 0° or 30° significantly increased at 60° of knee flexion (P = .036 and .042, respectively) and at 90° of knee flexion (P = .002 and .001, respectively). Conversely, the normalized MCP fixed at 60° and 90° remained at the same level as the intact knees at all angles of knee flexion. The normalized MCP of the lateral PF joint showed no significant difference at any fixation angle compared with intact knees.

CONCLUSION

To avoid excessive PF joint contact pressure after MPFL reconstruction, it may be best to fix polyester suture tape between 60° and 90° of knee flexion.

CLINICAL RELEVANCE

Fixation of the polyester suture tape with a knotless anchor for MPFL reconstruction should be at 60° to 90° of knee flexion to most closely restore PF joint contact pressures to that of the intact knee.

Core-Muscle Training and Neuromuscular Control of the Lower Limb and Trunk

CONTEXT

Comprehensive injury-prevention training (plyometric, agility, balance, and core-stability exercises) has been shown to decrease sport-related injury. The relationship between trunk control and sport-related injury has been emphasized; however, the isolated effects of core-muscle training are unclear.

OBJECTIVE

To investigate the effect of a simple 8-week core-muscle-training program on the neuromuscular control of the lower limb and trunk during jump landing and single-legged squatting.

DESIGN

Controlled laboratory study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

Seventeen female collegiate basketball players were randomly divided into training (n = 9; age = 19.7 ± 0.9 years) and control (n = 8; age = 20.3 ± 2.5 years) groups.

INTERVENTION(S)

The training group completed the core-muscle-training program in addition to daily practice, and the control group performed only daily practice. Kinematic and kinetic data during a drop-jump test and single-legged squat were acquired using a 3-dimensional motion-analysis system.

MAIN OUTCOME MEASURE(S)

Three-dimensional hip, knee, and trunk kinematics; knee kinetics; and isokinetic muscle strength were measured at the pretraining and posttraining phases.

RESULTS

For the drop-jump test, the maximal trunk-flexion angle increased (P = .008), and peak knee-valgus moment (P = .008) decreased in the training group. For the single-legged squat, the peak trunk-flexion angle increased (P = .04), and the total amount of trunk lateral-inclination angle (P = .02) and peak knee-valgus moment (P = .008) decreased in the training group. We observed no changes in the control group.

CONCLUSIONS

A consecutive 8-week core-muscle-training program improved lower limb and trunk biomechanics. These altered biomechanical patterns could be favorable to preventing sport-related injuries.

Biomechanical analysis of medial patellofemoral ligament reconstruction: FiberTape® with knotless anchors versus a semitendinosus tendon autograft with soft anchors

BACKGROUND

With the use of synthetic materials for medial patellofemoral ligament (MPFL) reconstruction, graft harvest is not necessary and this may facilitate post-operative rehabilitation. The purpose of this study was to compare the structural properties of MPFL reconstruction using a modern synthetic material (FiberTape® (FT), Arthrex) with knotless anchors or a semitendinosus (ST) tendon autograft with soft anchors.

METHODS

Nine human fresh-frozen amputated knees were used in this study. After the tensile strength of the native MPFL was measured, the MPFLs were reconstructed using two different surgical procedures, FT with knotless anchors (group A) and a ST with soft anchors (group B). Mechanical testing to failure of the reconstructed MPFLs was performed, and the ultimate load (N), stiffness (N/mm), and failure mode were recorded.

RESULTS

The mean (±standard deviation) ultimate load of the native MPFL was 130.6 ± 28.7 N, and all native MPFLs failed at the femoral insertion site. Ultimate load of group A was significantly higher than that of the native MPFL (175.9 ± 34.1 N, p < 0.05). In contrast, the ultimate load of group B was significantly lower than that of the native MPFL (102.7 ± 21.4 N, p < 0.05). The mean stiffness was significantly higher for MPFLs in group A (17.4 ± 4.3 N/mm) than in group B (8.5 ± 1.8 N/mm, p < 0.05). In group A, 5 specimens failed via a knotless anchor pullout at the femoral side, 3 via pullout of knotless anchors at the patella side and 1 via fracture (cheese cut) of the femur without breakage of knotless anchor. In group B, all specimens failed via soft anchor pullout at the patella side. There was no incidence of rupture of FT or ST.

CONCLUSION

FT with knotless anchors was stronger than a ST with soft tissue anchors for MPFL reconstruction.

Symptomatic bone marrow lesions induced by reduced bone mineral density in middle-aged women: a cross-sectional Japanese population study

BACKGROUND

The etiology of bone marrow lesions (BMLs) without knee osteoarthritis (KOA) and their association with bone fragility are unclear. We aimed to investigate the association between BMLs, bone mineral density (BMD), and bone markers in women without radiographic evidence of KOA.

METHODS

This single-center cross-sectional study in a Japanese population included 266 women without radiographic evidence of KOA, which was defined as a Kellgren-Lawrence grade < 2. All participants underwent coronal and sagittal T2-weighted fat-suppressed magnetic resonance imaging of their right knee. BML severity was scored according to the Whole-Organ MRI Scoring method. BMD was measured by dual-energy X-ray absorptiometry of the forearm. Levels of bone markers (bone-alkaline phosphatase [BAP], type I procollagen N-terminal propeptide [PINP], cross-linked N-telopeptide of type I collagen [NTx], and tartrate-resistant acid phosphatase-5b [TRACP-5b]), pentosidine, and homocysteine were assessed in the serum. Knee symptoms were evaluated on the basis of the Knee injury and Osteoarthritis and Outcome Score (KOOS). Participants were divided into symptomatic knee and asymptomatic knee groups on the basis of their KOOS according to the classification criteria for early KOA. Multiple linear regression analysis was performed to evaluate the relationship between BMLs, BMD, and bone markers.

RESULTS

The prevalence of BML was 35.3%. Age and some bone marker levels (BAP, PINP, NTx, and TRACP-5b) were higher, and all KOOS subscale scores and BMD were lower in participants with BMLs than in those without BMLs. On multiple linear regression analysis, BMD was negatively associated with BMLs (p = 0.014) in participants with symptomatic knees. There was no such association in participants with asymptomatic knees (p = 0.918). Among the bone markers, BAP (p = 0.006) and PINP (p = 0.043) were positively associated with BMLs in participants with symptomatic knees, while BAP (p = 0.038) and TRACP-5b (p = 0.011) were positively associated with BMLs in participants with asymptomatic knees.

CONCLUSIONS

In symptomatic Japanese women without radiographic evidence of KOA, BMD is negatively associated and some bone markers are positively associated with BMLs after adjustment for age and BMI. Thus, maintaining systemic bone metabolism could contribute to BML prevention in patients with pre-radiographic KOA.

Anatomical relationship between insertion sites, tunnel placement, and lateral meniscus anterior horn injury during single and double bundle anterior cruciate ligament reconstructions: A comparative macroscopic and histopathological evaluation in cadavers

PURPOSE

The influence of tunnel extension outside the anatomical anterior cruciate ligament (ACL) insertion in single-bundle (SB) or double-bundle (DB) ACL reconstruction is unclear. This study aimed to investigate the anatomical relationship between ACL insertion and tunnel extension in SB and DB ACL reconstruction, and the impact of tibial tunnel extension to the insertion of anterior horn of lateral meniscus in terms of injury.

METHODS

Forty-six paired cadaver knees (mean age, 82.7 ± 10.7 years) were used. Right and left knees were used for SB (10 mm) and DB tunnel reaming (6 mm for the anteromedial and posterolateral bundles). Tibial and femoral tunnels were created to aim at the center of the ACL insertion by arthroscopic visualization. The relationship between tunnel extension and ACL insertion was evaluated macroscopically, and there ratio in two groups were compared by chi-square test. Further, the relative risk for meniscus injury based on tunnel placement was estimated. Coronal section of tibia and parallel section to Blumensaat line in femur were prepared to evaluate the relationship among tunnel position, ACL insertion, and anterior horn of the meniscus histologically.

RESULTS

Tibial tunnel extension out of the ACL insertion was observed macroscopically in 9 (39.1%) knees of the SB group, and 3 (13.0%) of the DB group (p = 0.045). In femoral tunnels, extension out of the ACL insertion was seen in 8 (34.8%) knees of the SB group and 1 (4.3%) of the DB group (p = 0.011). Partial injuries of the lateral meniscus anterior horn (LMAH) were observed in 5 (21.7%) knees of the SB group and 1 (4.3%) knee of the DB group (p = 0.091). The relative risk for LMAH injury was calculated as 5.0 (odds ratio, 6.1). Microscopically, SB tunnels appeared to expand out of ACL insertion, both in the femur and tibia.

CONCLUSIONS

The incidence of tunnel extension out of the ACL insertion in femur and tibia were higher with SB than with DB reconstruction. Furthermore, injury rate of the LMAH in the DB group was lower.

Glenohumeral Rotational Deficit and Suprascapular Neuropathy in the Hitting Shoulder in Male Collegiate Volleyball Players

Objective

Repetitive overhead movements stress the dominant shoulder of volleyball players, potentially causing glenohumeral internal rotation deficit (GIRD) and suprascapular neuropathy. The aim of this study was to determine the prevalence of pathological GIRD and suprascapular neuropathy in male collegiate volleyball players.

Methods

We evaluated 22 male collegiate volleyball players and compared the range of motion, the isometric shoulder strength, the thickness of the infraspinatus (ISP) muscle, and the latency and amplitude of the suprascapular nerve [in a nerve conduction study (NCS)] between the hitting and contralateral shoulders. Correlations between the physical findings and each parameter were also determined.

Results

The internal rotation angle of the hitting shoulder (55.1±8.7°) was significantly less than that of the contralateral shoulder (64.5±10.2°) (P<0.001); pathological GIRD (≥20°) was found in four players (18.2%). Three players (13.6%) showed abnormal electrophysiological findings of the suprascapular nerve on the ISP muscle in the hitting shoulder. The external-to-internal rotation (ER/IR) torque ratio in the hitting shoulder (99±18%) was significantly lower than that in the contralateral shoulder (106±12%) (P=0.04); no significant differences were observed in ISP muscle thickness or NCS data between the hitting and contralateral shoulders.

Conclusion

The prevalence of pathological GIRD in male collegiate volleyball players was consistent with that of previous studies. Meanwhile, the prevalence of suprascapular neuropathy was less than that previously reported in high-level volleyball players. Preventive posterior rotator cuff strengthening programs are recommended to correct imbalances between ER and IR in the hitting shoulder, thereby decreasing the risk of shoulder injury.

Effects of different oral instructions on kinematic and kinetic parameters during drop vertical jump

[Purpose] This study aimed to examine the impact of changing the drop vertical jump stance time on kinematic and kinetic parameters by ordering to high jump or quick jump for consistent stance time and a more accurate assessment of anterior cruciate ligament injury risk. [Participants and Methods] The participants were 20 healthy female students. The drop vertical jump was started by instructing the participants to stand on a 30-cm platform with both legs stationary. The task was performed while the participants were instructed to perform high jump or quick jump. [Results] Stance time was significantly shorter with quick jump than with high jump. Quick jump showed significantly higher knee abduction angles at initial contact and peak vertical ground reaction force, and lower hip flexion, knee flexion, and ankle dorsiflexion angles at the lowest point of the center of mass. Quick jump showed a significantly higher peak vertical ground reaction force. The knee abduction moment at initial contact was not significantly different between the 2 conditions. [Conclusion] Quick jump was better than high jump for making stance time consistent, and the differences in kinematic and kinetic characteristics by oral instructions should be considered when using drop vertical jump.