Editorial Commentary: Meniscal Allograft Transplantation Results in Both Pain Relief and Chondroprotection.

Meniscal allograft transplantation (MAT) effectively alleviates symptoms of the meniscus deficiency. Thus, MAT is a widely accepted and recommended treatment for individuals with unicompartmental pain due to meniscus deficiency. Long-term follow-up studies have indicated that MAT yields favorable clinical outcomes, demonstrating high survivorship and low rates of serious complications. In addition, the ability of MAT to function akin to the native meniscus and shield the knee cartilage from osteoarthritis has been a subject of ongoing investigation, and recent direct magnetic resonance imaging evidence shows long-term chondroprotection following MAT. Cartilage lesions worsen during the meniscus deficiency period. Consequently, delaying MAT until patients become more symptomatic may lead to poor outcomes and low graft survivorship due to concomitant cartilage lesions. These findings prompt a reevaluation of the purpose and timing of MAT decisions for meniscectomy patients, suggesting a more proactive approach to recommending MAT, particularly for patients at high risk of postmeniscectomy syndrome and osteoarthritis progression.

A Deep Learning Model Enhances Clinicians' Diagnostic Accuracy to More Than 96% for Anterior Cruciate Ligament Ruptures on Magnetic Resonance Imaging.

PURPOSE: To develop a deep learning model to accurately detect anterior cruciate ligament (ACL) ruptures on magnetic resonance imaging (MRI) and to evaluate its effect on the diagnostic accuracy and efficiency of clinicians. METHODS: A training dataset was built from MRIs acquired from January 2017 to June 2021, including patients with knee symptoms, irrespective of ACL ruptures. An external validation dataset was built from MRIs acquired from January 2021 to June 2022, including patients who underwent knee arthroscopy or arthroplasty. Patients with fractures or prior knee surgeries were excluded in both datasets. Subsequently, a deep learning model was developed and validated using these datasets. Clinicians of varying expertise levels in sports medicine and radiology were recruited, and their capacities in diagnosing ACL injuries in terms of accuracy and diagnosing time were evaluated both with and without artificial intelligence (AI) assistance. RESULTS: A deep learning model was developed based on the training dataset of 22,767 MRIs from 5 centers and verified with external validation dataset of 4,086 MRIs from 6 centers. The model achieved an area under the receiver operating characteristic curve of 0.987 and a sensitivity and specificity of 95.1%. Thirty-eight clinicians from 25 centers were recruited to diagnose 3,800 MRIs. The AI assistance significantly improved the accuracy of all clinicians, exceeding 96%. Additionally, a notable reduction in diagnostic time was observed. The most significant improvements in accuracy and time efficiency were observed in the trainee groups, suggesting that AI support is particularly beneficial for clinicians with moderately limited diagnostic expertise. CONCLUSIONS: This deep learning model demonstrated expert-level diagnostic performance for ACL ruptures, serving as a valuable tool to assist clinicians of various specialties and experience levels in making accurate and efficient diagnoses. LEVEL OF EVIDENCE: Level III, retrospective comparative case series.

Intra-articular Histone Deacetylase Inhibitor Microcarrier Delivery to Reduce Osteoarthritis.

The histone deacetylase inhibitor (HDACi) was a milestone in the treatment of refractory T-cell lymphoma. However, the beneficial effects of HDACi have not been appreciated in osteoarthritis (OA). Herein, we implemented a microcarrier system because of the outstanding advantages of controlled and sustained release, biodegradability, and biocompatibility. The poly(d,l-lactide-co-glycolide) (PLGA) microcapsules have a regulated and sustained release profile with a reduced initial burst release, which can improve the encapsulation efficiency of the Chidamide. The emulsion solvent evaporation strategy was used to encapsulate Chidamide in PLGA microcapsules. The encapsulation of Chidamide was established by UV-vis spectra and scanning electron microscopy. Additionally, the inhibition of Tnnt3 and immune stimulation by Chidamide helped to inhibit cartilage destruction and prevent articular cartilage degeneration. Based on the results, the Chidamide in PLGA microcapsules provides a transformative therapeutic strategy for the treatment of osteoarthritis patients to relieve symptoms and protect against cartilage degeneration.

Meniscal allograft transplantation in discoid meniscus patients achieves good clinical outcomes and superior chondroprotection compared to meniscectomy in the long term.

PURPOSE: To compare the long-term clinical and radiological results of meniscal allograft transplantation (MAT) for discoid lateral meniscus (DLM) patients with MAT for non-discoid lateral meniscus patients and meniscectomy (ME) for DLM patients and, thus, to determine whether DLM patients are suitable candidates for MAT. METHODS: Eight MAT cases in DLM patients were identified (discoid MAT group), six MAT cases in non-discoid lateral meniscus patients (non-discoid MAT group) and ten total meniscectomy cases in DLM patients (discoid ME group) were matched as controls. Subjective evaluations, postoperative radiography and magnetic resonance imaging (MRI) were conducted at 5 years and 10-14 years, respectively. Joint degeneration was evaluated by the Kellgren-Lawrance (KL) grade and joint space width (JSW). MRI with T2 mapping sequences was used to quantitatively evaluate degeneration of the joint cartilage and shrinkage of the allografts. Student's t test was used to compare quantitative variables and the Mann‒Whitney U test was used to compare categorical variables. RESULTS: There was no difference in Lysholm, IKDC, Tegner or VAS scores amongst the discoid MAT, non-discoid MAT and discoid ME groups at the final follow-up. No revision surgery was performed in any MAT patient. The JSW narrowing in the discoid MAT group was better than that in the discoid ME group (0.8 ± 0.4 mm vs. 2.1 ± 1.3 mm, p = 0.012) and worse than that in the non-discoid MAT group (0.1 ± 0.1 mm, p = 0.003). The KL progression of the discoid MAT group was less than that of the discoid ME group (1.3 ± 0.7 vs. 2.3 ± 0.9, p = 0.034). The discoid ME group had worse cartilage lesion progression than the discoid MAT and non-discoid MAT groups. The allograft width of the DLM patients shrank more than that of the non-discoid patients at the meniscus midbody (3.6 ± 0.9 mm vs. 6.2 ± 1.9 mm, p = 0.015). CONCLUSION: Compared to meniscectomy, MAT achieved similar long-term symptom relief and superior chondroprotection in discoid meniscus patients. Despite more graft shrinkage, the outcomes of MAT in discoid meniscus patients were comparable to those in non-discoid meniscus patients. Therefore, DLM patients may be suitable candidates for MAT procedures. LEVEL OF EVIDENCE: Level III.

CT and MRI measurements of tibial tubercle lateralization in patients with patellar dislocation were not equivalent but could be interchangeable.

PURPOSE: To compare the values and the relationship of tibial tubercle lateralization measurements between computerized tomography (CT) and magnetic resonance imaging (MRI). METHODS: Sixty patients with patellar dislocation who underwent both CT and MRI of the same knee joint from November 2021 to February 2022 were included in our study. The intraclass correlation coefficient (ICC) and Bland-Altman analysis were performed to evaluate the reliability of tibial tubercle-trochlear groove (TT-TG), tibial tubercle-Roman arch (TT-RA), and tibial tubercle-posterior cruciate ligament (TT-PCL) distance measurements. The values of CT and MRI measurements using the same bony landmarks were compared for the difference. Pearson correlation analysis and linear regression analysis were performed to assess the correlation between CT and MRI measurements. Finally, the estimated values obtained from the regression equation were compared with the actual values obtained from the radiological measurement to evaluate the accuracy of the equations. RESULTS: A total of 60 patients with patellar dislocation who underwent both CT and MRI of the same knee joint were included in this study. The included measurements showed excellent agreement with ICCs > 0.9. TT-TG distance measured on CT (19.5 ± 5.1 mm) had a mean of 7.1 mm higher than that on MRI (12.4 ± 4.7 mm) (P < 0.001). The mean value of TT-RA distance was 22.5 ± 3.7 mm on CT and 16.7 ± 4.9 mm on MRI (P < 0.001), showing a mean difference of 5.8 mm. The values of TT-TG distance measured by CT and MRI were significantly correlated (R = 0.5, P < 0.001). The values of TT-RA distance between these two modalities showed a better correlation than that of TT-TG distance (R = 0.6, P < 0.001). The interchange values of TT-TG distance and TT-RA distance between CT and MRI can be obtained using regression equations (TT-TG distance: y = 0.6x + 12.3; TT-RA distance: y = 0.5x + 14.4). CONCLUSION: The values of tibial tubercle lateralization measured by MRI may be underestimated compared with those measured by CT. Although the values measured on CT and MRI are not equivalent, the value in the other modality can be estimated. Therefore, an additional CT scan for tibial tubercle lateralization evaluation may not be necessary. LEVEL OF EVIDENCE: Level II.

Anterolateral Structure Reconstruction Similarly Improves the Stability and Causes Less Overconstraint in Anterior Cruciate Ligament-Reconstructed Knees Compared With Modified Lemaire Lateral Extra-articular Tenodesis: A Biomechanical Study.

PURPOSE: To compare the kinematics of anterolateral structure (ALS) reconstruction (ALSR) and lateral extra-articular tenodesis (LET) in ACL-ALS-deficient knees with anterior cruciate ligament (ACL) reconstruction. METHODS: Ten fresh-frozen cadaveric knees with the following conditions were tested: (1) intact, (2) ACL-ALS deficiency, (3) ACL reconstruction (ACLR), (4) ACLR combined with ALSR (ACL-ALSR) or LET (ACLR+LET). Anterior translation and tibial internal rotation were measured with 90-N anterior load and 5 N·m internal torque at 0°, 30°, 60°, and 90°. The anterolateral translation and internal rotation were also measured during a simulated pivot-shift test at 0°, 15°, 30°, and 45°. The knee kinematic changes in all reconstructions were compared with each other, with intact knees as the baseline. RESULTS: Isolated ACLR failed to restore native knee kinematics in ACL-ALS-deficient knees. Both ACL-ALSR and ACLR+LET procedures decreased the anterior instability of the ACLR. However, ACLR+LET caused overconstraints in internal rotation at 30° (-3.73° ± 2.60°, P = .023), 60° (-4.96° ± 2.22°, P = .001) and 90° (-6.14° ± 1.60°, P < .001). ACL-ALSR also overconstrained the knee at 60° (-3.65° ± 1.90°, P < .001) and 90° (-3.18° ± 2.53°, P < .001). For a simulated pivot-shift test, both combined procedures significantly reduced the ACLR instability, with anterolateral translation and internal rotation being overconstrained in ACLR+LET at 30° (-3.32 mm ± 3.89 mm, P = .005; -2.58° ± 1.61°, P < .001) and 45° (-3.02 mm ± 3.95 mm, P = .012; -3.44° ± 2.86°, P < .001). However, the ACL-ALSR overconstrained only the anterolateral translation at 30° (-1.51 mm ± 2.39 mm, P = .046) and internal rotation at 45° (-2.09° ± 1.70°, P < .001). There were no significant differences between the two combined procedures at most testing degrees in each testing state, except for the internal rotation at 30° (P = .007) and 90° (P = .032) in internal rotation torque. CONCLUSION: ACL reconstruction alone did not restore intact knee kinematics in knees with concurrent ACL tears and severe ALS injury (ACL-ALS-deficient status). Both ACL-ALSR and ACLR+LET procedures restored knee stability at some flexion degrees, with less overconstraints in internal rotation resulting from ACL-ALSR. CLINICAL RELEVANCE: For patients with combined ACL tears and severe ALS deficiency, isolated ACLR probably results in residual rotational and pivot-shift instability. Both ACL-ALSR and ACLR+LET show promise for the improvement of knee stability, whereas ACL-ALSR has less propensity for knee overconstraint.

The immediate meniscal allograft transplantation achieved better chondroprotection and less meniscus degeneration than the conventional delayed transplantation in the long-term.

PURPOSE: The purpose of this study was to compare the long-term clinical and radiological outcomes between the immediate and delayed meniscus allograft transplantation (MAT). METHODS: Nine menisci were transplanted immediately after total meniscectomy (immediate group, IM), and 10 menisci were delayed transplanted in patients with the median of 35 months (range 9-92 months) after total meniscectomy (delayed group, DE). Patient's subjective clinical outcomes including VAS, IKDC, Lysholm and Tegner scores as well as muscle strength measures were compared. Joint degeneration was evaluated by both radiographs to assess joint space width narrowing, Kellegren-Lawrence (KL) grade and MRI with T2 mapping sequences to quantitatively analyze both cartilage and meniscal allograft degeneration. RESULTS: The median follow-up time was 10.8 years (range 10-14 years). The IKDC (IM vs DE, 89.8 vs 80.9, n.s.) and Lysholm scores (IM vs DE, 87.7 vs 78.0, n.s.) were close in two groups, while the IM group showed slightly lower VAS (IM vs DE, 0.2 vs 1.5, p = 0.031), higher Tegner score (IM vs DE, 7 vs 3.5 p = 0.021) and better quadriceps muscle strength. The IM group had less joint space narrowing (IM vs DE, 0.35 mm vs 0.71 mm, n.s.), less KL grade progression (IM vs DE, 0.6 vs 1.7, p = 0.041) on radiographs and less chondral lesions development on MRIs (Cartilage Degeneration Index, IM vs DE, 252 vs 2038, p = 0.025). All meniscal grafts exhibited degeneration by showing grade 3 signal on MRI, and 4 (4/9) in the IM group and 8 (8/10) cases in the DE group. The T2 value of cartilage and meniscal allograft in the IM group was close to that of the healthy control and was significantly lower than that of the DE group. CONCLUSION: Compared to the conventional delayed MAT, the immediate MAT achieved better cartilage and meniscus protection in the long-term, while its superiority in patient-reported outcomes was limited. LEVEL OF EVIDENCE: IV.

Higher pathologic threshold of increased tibial tuberosity-trochlear groove distance should be considered for taller patients.

PURPOSE: The aim of this study was to evaluate the correlation between tibial tuberosity-trochlear groove distance (TT-TG) and body height or knee size, and to find height-related pathologic thresholds of increased TT-TG. METHODS: One-hundred and fifty-three patients with recurrent patellar instability and 151 controls were included. The TT-TG was measured on axial computed tomography (CT) images. Femora width and tibial width were selected to represent knee size. The correlation of TT-TG and gender, body height, femora width, and tibial width was evaluated. The height-related pathologic threshold of increased TT-TG was produced according to Dejour's method. To combine TT-TG with body height and knee size, three new indexes were introduced, ratio of TT-TG to body height (RTH), ratio of TT-TG to femoral width (RTF), and ratio of TT-TG to tibial width (RTT). The ability to predict patellar instability was assessed by the receiver-operating characteristic (ROC) curve, odds ratios (ORs), sensitivity, and specificity. RESULTS: In patients with patellar instability, TT-TG showed significantly correlation with patient height, femoral width, and tibial width respectively (range r = 0.266-0.283). This correlation was not found in the control group. The pathologic threshold of TT-TG was 18 mm in patients < 169 cm (53%), and the mean TT-TG was 21 mm in patients ≥ 169 cm (54%). There was significant difference in RTH, RTF, and RTT between the two groups. RTH, RTF and RTT have similar large area under the curve (AUC) with TT-TG. CONCLUSIONS: TT-TG showed significant correlation with body height and knee size, respectively. The pathologic threshold of increased TT-TG was suggested to be 21 mm for patients [Formula: see text] 169 cm and 18 mm for patients [Formula: see text] 169 cm. Body height-related pathologic threshold provided a supplement for indications of tibial tuberosity medialization. LEVEL OF EVIDENCE: IV.

A Secondary Injury of the Anterolateral Structure Plays a Minor Role in Anterior and Anterolateral Instability of Anterior Cruciate Ligament-Deficient Knees in the Case of Functional Iliotibial Band.

PURPOSE: To analyze the contribution of a secondary anterolateral structure (ALS) deficiency to knee instability based on anterior cruciate ligament (ACL) deficiency, in the condition of a functional iliotibial band (ITB). METHODS: Nine freshly-frozen cadaveric knees were sectioned sequentially to create ACL deficiency and ACL-ALS deficiency, using intact knees before sectioning as controls. When ITB was tensioned with 30 N, 4 separate aspects of knee instability were tested as follows: anterior translation in 90 N anterior load, isolated internal rotation in 5 N·m internal rotational torque from 0° to 90° in 15° increments, and anterolateral translation and internal rotation during a simulated pivot-shift test at 0°, 15°, 30°, and 45°. The contribution of ACL deficiency alone and additional ALS deficiency to knee instability were evaluated. RESULTS: The addition of an ALS lesion produced no significant exacerbation of either anterior translational or pivot shift instability in ACL-deficient knees. Additional ALS deficiency in an ACL-deficient knee resulted in a significant increase in isolated internal rotation from 45° to 90° (P = .001 at 45° and P < .001 in other cases). After sequentially sectioning, the contribution to instability of additional ALS deficiency to the entire instability in ACL-ALS-deficient knees was significantly smaller than that of ACL deficiency alone during anterior load and pivot-shift test (P < .001 in all cases), but significantly contributed more to isolated internal rotational instability at 60° (P = .011) and 90° (P = .015). CONCLUSIONS: When ITB was tensioned, ALS played a minor role in controlling both anterior or pivot shift stability in ACL-deficient knees but a major role in restraining isolated internal rotation from 45° to 90°. CLINICAL RELEVANCE: In the condition of functional ITB, concomitant ALS injury might not exacerbate anterior and pivot-shift instability after ACL rupture, while affecting isolated internal rotation stability at higher flexion.

Using Anatomic Landmarks to Locate Schöttle's Point Was Accurate Without Fluoroscopy During Medial Patellofemoral Ligament Reconstruction.

PURPOSE: The purpose of the present study was to analyze the anatomic landmarks of Schöttle's point and establish a locating method for identification. METHODS: From 2013 to 2016, patients undergoing medial patellofemoral ligament (MPFL) reconstruction for patellofemoral instability were enrolled. INCLUSION CRITERIA: at least 2 episodes of patellar dislocation. EXCLUSION CRITERIA: previous knee surgeries, open physes, severe trochlear dysplasia， tibial tuberosity lateralization, or patella alta. Group A: From January 2013 to December 2013, preoperative 3-dimensional computed tomography (3D-CT) images were obtained. Anatomic features of Schöttle's point were measured on the 3D-CT images. A Schöttle's point locating method with 2 distinct landmarks was established. Group B: From January 2014 to January 2016, consecutive MPFL reconstructions were performed. The placement of Schöttle's point was following the established method without fluoroscopy. The accuracy of femoral tunnel positions was assessed on the 3D-CT images postoperatively. RESULTS: CT images of 53 knees were obtained in group A. Forty-seven MPFL reconstructions were performed in group B. No significant difference was found between the 2 groups regarding to demographic characteristics. The intraclass correlation coefficients were excellent for all measures (r = 0.97). In group A, Schöttle's point was 8.1 ± 0.2 mm (95% confidence interval [CI], 7.7-8.5) distal to the apex of the adductor tubercle and 8.0 ± 0.3 mm (95% CI, 7.4-8.6) anterior to the posterior edge. Apex of the adductor tubercle was defined as the most convex point, and posterior edge was defined as the edge of the posteromedial cortex in the transition area between the medial condyle and femoral shaft. In group B, 44 of 47 femoral tunnels (93.6%) were considered localized in the proper zone. CONCLUSIONS: Schöttle's point was approximately 8 mm distal to the apex of the adductor tubercle and 8 mm from the posterior edge. Schöttle's point locating method without fluoroscopy had high accuracy. LEVEL OF EVIDENCE: Level IV, case series.

Tibial Tubercle Osteotomy May Not Provide Additional Benefit in Treating Patellar Dislocation With Increased Tibial Tuberosity-Trochlear Groove Distance: A Systematic Review.

PURPOSE: To examine the indications and outcomes of medial patellofemoral ligament reconstruction (MPFLR) with or without tibial tubercle osteotomy (TTO) in treating recurrent or habitual patellar dislocation with an increased tibial tuberosity-trochlear groove (TT-TG) distance. METHODS: We performed a literature search of the established medical databases Cochrane Central, PubMed-MEDLINE, EMBASE, and Web of Science. The inclusion criteria were as follows: skeletally mature patients with recurrent or habitual patellar dislocation and an increased TT-TG distance, treatment with MPFLR combined with a TTO procedure or isolated MPFLR, and reporting of clinical outcomes and complications. Each study was assessed for quality and the level of evidence. The general characteristics, indications, surgical techniques, TT-TG distance, clinical results, imaging evaluation findings, and complications of each study were recorded. RESULTS: Nine studies consisting of 288 knees met the inclusion criteria. The average Coleman score was 71.56 (range, 55-83). The threshold for an increased TT-TG distance ranged from 16 to 20 mm in the included studies. Similar good postoperative outcomes were reported in patients with an increased TT-TG distance treated with MPFLR with versus without a TTO procedure. The mean postoperative Lysholm score ranged from 75.0 to 94.7 (I2 = 87.6%) in the isolated MPFLR group and from 85.0 to 87.6 (I2 = 16.3%) in the TTO-with-MPFLR group. Similar postoperative congruence angles were reported in both groups. The postoperative redislocation rate ranged from 0% to 4.2% in the TTO-with-MPFLR group, and no redislocation was found in the isolated MPFLR group. The postoperative apprehension sign was only reported in isolated MPFLR patients. CONCLUSIONS: The outcomes of MPFLR with or without TTO to treat recurrent or habitual patellar dislocation with an increased TT-TG distance appeared similar. However, this study was limited by the considerable heterogeneity, variety of techniques, variety of TT-TG distances, and variability in patella alta and trochlear dysplasia among the included studies. LEVEL OF EVIDENCE: Level IV, systematic review of Level II to IV studies.

Double-bundle anterior cruciate ligament reconstruction technique has advantages in chondroprotection and knee laxity control compared with single-bundle technique : A long-term follow-up with a minimum of 12 years.

PURPOSE: To compare the long-term clinical outcomes of single-bundle anterior cruciate ligament reconstruction (SBR) and double-bundle anterior cruciate ligament reconstruction (DBR) in patients with isolated anterior cruciate ligament (ACL) rupture, presenting no meniscus injury and no obvious preoperative cartilage degeneration. METHODS: One hundred and three patients (38.6 ± 9.5 years) with a median follow-up of 151.6 months (range, 144-189 months) completed the retrospective study (SBR group: n = 51; DBR group: n = 52). Clinical outcomes were evaluated with physical examinations, KT-2000 anterior and posterior stability measurement with the knee in 30º of flexion, International Knee Documentation Committee (IKDC) subjective score, Tegner score, Lysholm score; magnetic resonance imaging (MRI) (3.0 T) was performed, and International Cartilage Repair Society (ICRS) cartilage degeneration grades were determined. Multivariate analysis was performed to identify factors associated with cartilage degeneration. RESULTS: There were significant differences in the pre- and postoperative IKDC, Lysholm and Tegner scores between the SBR and DBR groups. The SBR group had over double the rate of positive pressure/rub patellar test results (SBR vs DBR, 43.1% vs. 19.2%, p < 0.011). The KT-2000, pivot-shift and Lachman test results were stratified and analyzed, and significant differences between the SBR and DBR groups were found (p < 0.05, respectively). The distribution of ICRS grades differed significantly between the groups at the last follow-up (p = 0.013). A multivariate analysis found that age and operation procedures were significant predictors of 0 and non-0 ICRS grades (odds ratio, 6.077 [95% CI 2.117-17.447] and 0.210 [95% CI 0.068-0.654], respectively) (p < 0.05). CONCLUSION: Both SBR and DBR achieved overall good long-term results. DBR had advantages in objective outcome measures and was superior in preventing the occurrence of cartilage degeneration. Age was identified as a preoperative risk factor for significant postoperative cartilage degeneration. LEVEL OF EVIDENCE: III. ClinicalTrials.gov: NCT03984474.

Thermosensitive Hydrogels as Scaffolds for Cartilage Tissue Engineering.

Articular cartilage defects, caused by trauma, osteoarthritis, or other diseases, always lead to severe joint pain and joint dysfunction. Without access to progenitor cells and the supply of blood and nutrients, the impaired articular cartilage would be short of the capability to self-repair. Although the present clinical treatments, including autogenous and allograft osteochondral transplantation, microfracture technique, and so forth, have shown some efficacies, their drawbacks, such as donor insufficiency and poor-integration with adjacent tissue, limit the satisfactory repair of articular cartilage defects and cause unsatisfied prognosis. Cartilage tissue engineering, involving the combination of progenitor cells with scaffolds, which serve as artificial extracellular matrices (ECMs), provides a promising strategy for cartilage regeneration. Recently, thermosensitive hydrogels have attracted much attention as scaffolds for cartilage tissue engineering owing to their unique physical properties analogous to the native ECM. In this review, we summarize the fabrication, characterization of newly reported thermosensitive hydrogels as cartilage tissue engineering scaffolds. The potential challenges and future perspectives are proposed.

Quadriceps-sparing versus traditional medial parapatellar approaches for total knee arthroplasty: a meta-analysis.

BACKGROUND: There is still controversy regarding whether Quadriceps-sparing (QS) approach for total knee arthroplasty (TKA) lead to better earlier recovery as well as compromising low limb alignment and prosthesis position compared with conventional medial parapatellar (MP) approach. To overcome the shortcomings and inaccuracies of single studies, the clinical outcomes and radiographic assessments of QS approach and MP approach were evaluated through meta-analysis. METHODS: We performed this meta-analysis according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. A literature search was conducted in the PubMed, EMBase, Cochrane Collaboration Library and Web of Science databases. Our search strategy followed the requirements of the Cochrane Library Handbook. The study selection, data extraction and assessment of methodological quality were independently completed by four authors. And subgroup analysis and publication bias were also performed in the study. RESULTS: Eight prospective randomized controlled trials (RCTs) and eight retrospective studies were identified. Overall meta-analysis and subgroup meta-analysis of RCTs identified the QS approach mainly was associated with increased Knee Society function score beyond 24 months postoperatively (weighted mean difference [WMD] 1.78, P = 0.0004) (WMD 1.86, P = 0.0002), and improved range of motion 1-2 weeks postoperatively (WMD 5.84, P < 0.00001) (WMD 4.87, P = 0.002). Besides, lower visual analogue scale on postoperative day 1 (WMD -0.91, P = 0.02), shorter hospital stay (WMD -0.88, P = 0.02) and shorter incision (extension) (WMD -4.62, P < 0.00001) were indicated in overall meta-analysis. However, surgical and tourniquet time was significantly longer in QS group by both overall and subgroup meta-analysis. CONCLUSIONS: QS approach may accelerate early recovery without increasing the risk of malalignment of low limb and malposition of prosthesis.

Vascular Compromising Effect of Drilling for Osteochondral Lesions of the Talus: A Three-Dimensional Micro-Computed Tomography Study.

PURPOSE: To explore an optimal drilling depth and direction for osteochondral lesions of the talus based on a 3-dimensional vascular microarchitecture model constructed with micro-computed tomography (microCT). METHODS: Twelve tali were perfused with the contrast agent and then scanned with microCT. The talar dome was divided into 9 zones, and the vessel densities were measured at the subchondral depths of 0 to 5 mm, 5 to 10 mm and 10 to 15 mm in each zone. The anterolateral (AL) and posterolateral (PL) approaches of retrograde drilling were simulated and the vascular compromising effect was evaluated. RESULTS: The vessel density of the 0- to 5-mm depth was lower than that of the 5- to 10-mm (P = .001) and 10- to 15-mm (P = .007) depths, but no significant difference was found between the 5- to 10-mm and 10- to 15-mm depths (P > .9999). The vessel density in the 5- to 10-mm depth of medial talar dome was similar to that of the adjacent zones (P = .05). Vessel density in the 5- to 10-mm depth around the lateral talar dome was higher in the anterior and medial side. The anterolateral approach disturbed the main intraosseous vessels from the tarsal canal-tarsal sinus, causing extensive vascular compromise in the talus neck and body, whereas the posterolateral approach disturbed only the vessels near the tunnel. CONCLUSIONS: The vessel density changed greatly from the subchondral 0- to 5-mm to the 5- to 10-mm depth. The vessel densities of the 5- to 10-mm depth around the medial talar dome were similar, whereas the anterior and medial side of the lateral talar dome was better vascularized. The posterolateral approach caused less vascular damage than the anterolateral approach. CLINICAL RELEVANCE: The anterograde drilling depth was preferable to the subchondral 5- to 10-mm depth. There was no preferred drilling direction for the osteochondral lesion in the medial talar dome, whereas it is preferable to drill anteriorly or medially in the lateral dome. The posterolateral approach might be a safer alternative for retrograde drilling.

Clinical and radiologic outcomes of two patellar resection techniques during total knee arthroplasty: a prospective randomized controlled study.

PURPOSE: A cutting guide technique for patella resurfacing in total knee arthroplasty was expected to result in less patellofemoral syndromes. The aim of this study was to identify differences in the patellofemoral function, clinical outcomes, and radiographic parameters between the freehand and cutting guide patellar resection techniques in patients undergoing total knee arthroplasty. METHODS: A prospective randomized controlled trial was conducted. The study was registered in a public trials registry (International Standard Randomized Trial No. NCT02268097). One-hundred total knee arthroplasties in 100 patients were randomly allocated into one of the two groups, and their results were followed for a mean of 28 months (range, 18 to 38 months) in a double-blind (both patient and evaluator), prospective study. Evaluation was performed by an independent observer using patellofemoral functional capacity, the Knee Society clinical rating system, the Western Ontario and McMaster Universities Osteoarthritis Indices, and radiographic examination. RESULTS: In total, 14% of the patients were lost to follow-up. There was no difference in the incidence of anterior knee pain between the two groups. No patients received or required revisions. There was a significant difference in the outliers of lateral patellar tilt between the freehand and cutting guide groups (> 10°) (p = 0.036); however, the mean value of lateral patellar tilt did not differ significantly. There were no differences between groups with respect to the 30 seconds stair climbing test, complications, the Knee Society clinical rating system, the Western Ontario and McMaster Universities Osteoarthritis Indices, patient satisfaction, physical examination, hip-knee-ankle angle, lateral patellar displacement, or the Insall-Salvati ratio. Meanwhile, gender, age, weight, height, body mass index, pre-operative Knee Society scores, and pre-operative range of motion were not found to be related to the development of anterior knee pain. CONCLUSIONS: Cutting guide technique group did not yield lower incidence of anterior knee pain. More outliers of lateral patellar tilt were observed in the freehand technique group. Overall, all patients in both groups had identical results in terms of patellofemoral functional capacity, clinical outcomes, and other radiographic results.

Risk of total/subtotal meniscectomy for respective medial and lateral meniscus injury: correlation with tear type, duration of complaint, age, gender and ACL rupture in 6034 Asian patients.

BACKGROUND: To evaluate the risk factor associated with total or subtotal meniscectomy for respective medial and lateral meniscus injury. METHODS: The data of all the meniscus injured patients undergoing arthroscopy in our institute between January 15th, 2000 and December 31st, 2008 was collected and 6034 patients with 7241 injured menisci met the inclusion criteria. The mean patient age was 33.6 ± 14.9 years and there were 4785 males and 2456 females with 3568 medial and 3673 lateral menisci. The decision tree approach was applied to investigate the correlation of the tear type, the duration of complaint, age, gender, ACL rupture and total/subtotal meniscectomy for respective medial and lateral meniscus. RESULTS: The tear type was associated with both medial (χ2 = 70.901, P < 0.001) and lateral (χ2 = 268.019, P < 0.001) total/subtotal meniscectomy. The strongest risk of total/subtotal meniscectomy of both medial and lateral meniscus tear was shown for the complex tear followed by the longitudinal, oblique, horizontal and radial tear of the medial meniscus and followed by horizontal, longitudinal, radial and oblique tear of the lateral meniscus. The risk of total/subtotal medial meniscectomy was significantly elevated for the patients with complex tear and the age of ≤40 years old (χ2 = 21.028, P < 0.001) and those with the oblique, horizontal or radial tear accompanied by ACL rupture (χ2 = 6.631, P = 0.01). Besides, the duration of complaint was also associated with total/subtotal meniscectomy of the medial longitudinal tear with ACL rupture (χ2 = 17.155, P < 0.001). On the other side, the risk of total/subtotal lateral meniscectomy was significantly elevated for the complex tear of the female patients (χ2 = 5.877, P = 0.015) with no ACL rupture (χ2 = 50.501, P < 0.001). The ACL rupture was associated with a decreased risk of total/subtotal meniscectomy for all the types of the lateral meniscus (complex: χ2 = 50.501, P < 0.001; horizontal: χ2 = 20.897, P < 0.001; oblique: χ2 = 27.413, P < 0.001; longitudinal and radial: χ2 = 110.85, P < 0.001). CONCLUSION: Analyzing data from a big sample available in an Asian patient database, we found different risk factors associated with total/subtotal meniscectomy for respective medial and lateral meniscus. Identifying patients at high risk for total/subtotal meniscectomy may allow for interventions after meniscus injury.

A systematic review of double-bundle versus single-bundle posterior cruciate ligament reconstruction.

BACKGROUND: Posterior Cruciate Ligament (PCL) ruptures are common sports injuries. One of the key controversies in PCL reconstruction is whether double-bundle reconstruction provides biomechanical and clinical outcomes superior to single-bundle reconstruction. METHODS: We performed a comprehensive search in multiple databases to evaluate the advantages of single-bundle or double bundle reconstructions in anteroposterior stability, graft tension, rotational stability, and functional outcome. RESULTS: Biomechanical comparisons evaluating anteroposterior stability described either no difference or increased stability in double-bundle reconstructions. Comparing these results is complicated by different graft choices, tensioning techniques, and tunnel positions. Biomechanical studies of graft tension demonstrated conflicting results regarding the optimal reconstruction technique. Seven retrospective clinical studies of single- and double-bundle reconstructions with methodological limitations reported no difference in clinical outcome. CONCLUSIONS: The superiority of single-bundle or double-bundle posterior cruciate ligament reconstruction remains uncertain.

Intraoperative anthropomorphic study of anterior femoral condyles compared with sizing of femoral arthroplasty.

PURPOSE: The present study was designed to compare the dimensions of the anterior femoral condyle with those of the anterior component flange using intraoperative morphological data. METHODS: Overall, 1227 knees in 962 patients were included in this study. The height of the anterior lateral/medial condylar height (ALCH/AMCH) was measured and compared between men and women. These morphological data were compared with the dimensions of the chosen component for each patient. The lateral/medial anterior femoral offset was calculated, and the over-/understuffing rates were compared between men and women. RESULTS: The median ALCH in men was 8.5 mm (6.5, 10.0 mm) versus 7.0 mm (6.0, 9.0 mm) in women. The median AMCH in men was 4.0 mm (2.5, 6.0 mm) versus 3.5 mm (2.5, 6.0 mm) in women. There was a significant difference between the genders with respect to ALCH (p < 0.05). When the dimensions of the component were compared with those of the native knee, the anterior lateral flange height was smaller than the native knees (1.3 mm in male, 0.7 mm in female), but the anterior medial flange height was larger than the corresponding condyle (1.8 mm in male, 1.8 mm in female). A significant difference was observed between the genders with respect to the ideal fit rate of ALCH (p < 0.01). CONCLUSION: The results demonstrate that gender differences exist in the anterior lateral condyles of knees. The anterior flange of component is not designed to precisely reproduce normal trochlear anatomy. LEVEL OF EVIDENCE: II.

Optimal patellar alignment with minimally invasive approaches in total knee arthroplasty after a minimum five year follow-up.

PURPOSE: Patellofemoral syndrome is still a common complication after total knee arthroplasty (TKA). However, the effects of specific surgical approaches on patellar tracking and alignment remain incompletely understood. In this study, we compared patellar alignment in patients who underwent TKA via three different techniques. METHODS: A total of 96 patients who completed a minimum follow-up of five years were involved in three groups: 30 patients were treated with the traditional medial parapatellar approach (MPP group), 35 patients were treated with the mini-medial parapatellar approach (MMP group) and 31 were treated with a quadriceps-sparing approach (QS group). Radiographic data for patellar alignment and clinical results were compared. RESULTS: Patellar tilt and patellar displacement at the final follow-up evaluation differed significantly among the three groups [P < 0.01, analysis of variance (ANOVA)]. The MMP and QS groups exhibited more proper patellar alignment than the MPP group. The clinical results did not differ significantly among the groups (P > 0.05, ANOVA). In addition, there were no correlations between postoperative patellar alignment and clinical scores. CONCLUSIONS: The results of this study indicate that TKA performed using minimally invasive approaches yields superior patellar alignment compared to the traditional MPP approach.