Patellar resurfacing has minimal impact on in vitro tibiofemoral kinematics during deep knee flexion in total knee arthroplasty

BackgroundWhile patellar resurfacing can affect patellofemoral kinematics, the effect on tibiofemoral kinematics is unknown. We hypothesized that patellar resurfacing would affect tibiofemoral kinematics during deep knee flexion due to biomechanical alteration of the extensor mechanism.MethodsWe performed cruciate-retaining TKA in fresh-frozen human cadaveric knees (N = 5) and recorded fluoroscopic kinematics during deep knee flexion before and after the patellar resurfacing. To simulate deep knee flexion, cadaver knees were tested on a dynamic, quadriceps-driven, closed-kinetic chain simulator based on the Oxford knee rig design under loads equivalent to stair climbing. To measure knee kinematics, a 2-dimensional to 3-dimensional fluoroscopic registration technique was used. Component rotation, varus-valgus angle, and anteroposterior translation of medial and lateral contact points of the femoral component relative to the tibial component were calculated over the range of flexion.ResultsThere were no significant differences in femoral component external rotation (before patellar resurfacing: 6.6 ± 2.3°, after patellar resurfacing: 7.2 ± 1.8°, p = 0.36), and less than 1° difference in femorotibial varus-valgus angle between patellar resurfacing and non-resurfacing (p = 0.01). For both conditions, the medial and lateral femorotibial contact points moved posteriorly from 0° to 30° of flexion, but not beyond 30° of flexion. At 10° of flexion, after patellar resurfacing, the medial contact point was more anteriorly located than before patellar resurfacing.ConclusionDespite the potential for alteration of the knee extensor biomechanics, patellar resurfacing had minimal effect on tibiofemoral kinematics. Patellar resurfacing, if performed adequately, is unlikely to affect postoperative knee function.     

Comparison of the outcomes between two different target points after open wedge high tibial osteotomy: The Fujisawa point versus the lateral tibial spine

BackgroundThe purpose of this study was to compare the clinical, radiographic and arthroscopic outcomes after open wedge high tibial osteotomy (OWHTO) aiming either at the Fujisawa point (group F) or the lateral tibial spine (LTS, group L).MethodsBetween January 2011 and May 2017, 89 cases underwent implant removal procedures with second-look arthroscopy at 19.8 months after OWHTO with first-look arthroscopy. Among them, 24 and 65 cases were enrolled in groups F and L, respectively. Outcomes included clinical (evaluated using the Western Ontario and McMaster Universities Osteoarthritis index and the International Knee Documentation Committee subjective score), radiographic (observation of the mechanical axis (MA) and tibial slope), and arthroscopic (including chondral lesions of the medial femoral condyle (MFC), trochlea, and patella scored according to the International Cartilage Repair Society grading) measures, investigated at index surgery and implant removal surgery. Outcomes were compared between two groups.ResultsPreoperative clinical characteristics and postoperative outcomes were similar between both groups. The mean postoperative MA was significantly lower in group F compared with group L (− 3.9° vs. − 1.6°, respectively; P < 0.001). Similar MFC cartilage grading changes from index surgery to second look surgery were shown; however, further progression of patellofemoral grading was shown in group F.ConclusionsOWHTO aimed at the LTS has similar clinical outcomes to Fujisawa point. Surgery aimed at the LTS was slightly less corrected. Targeting the LTS could be an option after consideration of joint geometry and patellofemoral joint problems.     

How does geometric change after open-wedge high tibial osteotomy affect anterior cruciate ligament status?

BackgroundOpen-wedge high tibial osteotomy (OWHTO) produces three- dimensional (3D) geometric changes. Among them, increased posterior tibial slope (PTS), and altered coronal inclination that induces unintended tibial translation may affect anterior cruciate ligament (ACL) status. The purpose of current study was to evaluate the geometric changes following OWHTO, such as increasing PTS and decreasing tibial subluxation, which may affect the status of ACL.MethodsFrom April 2014 to December 2015, a total of 72 knees in 64 patients that underwent OWHTO, second-look arthroscopy, and magnetic resonance imaging (MRI) assessment, were enrolled. Preoperative and postoperative coronal and sagittal translation, joint line orientation angle, the distance between medial femoral notch marginal line and medial tibial spine, and PTS were evaluated. ACL status was arthroscopically graded from grade 1 (best) to 4 (worst). The MRI signal of the graft in three portions (proximal, middle, and distal) was graded from grade 1 (best) to 4 (worst).ResultsHigh grade (3: partial, and 4: complete rupture) was noted in 28 cases (38.9%) at the second-look arthroscopy compared with 10 cases (13.9%) at index arthroscopy. The MRI signal grade significantly increased at follow up MRI compared with preoperative MRI (P < 0.01). An increased signal was commonly noted in the middle and distal portions of the graft.ConclusionsGeometric changes after OWHTO were related to ACL deterioration. The ACL was commonly affected at the middle and distal portions and rarely at the proximal portion. There is a possibility of impingement because of the geometric changes.Level of evidence: Level IV     

Kellgren–Lawrence grade of osteoarthritis is associated with change in certain morphological parameters

BackgroundTo compare selected morphological parameters between normal and osteoarthritic (OA) knees, as well as to evaluate differences in these parameters between Kellgren–Lawrence (K-L) grades of OA.MethodsKnee joint morphology was evaluated using magnetic resonance (MR) images of 200 participants with knee OA (50 each of K-L grades 1–4) and 50 without knee OA, matched for age, body mass index, sex, and tibiofemoral angle. Knees with a coronal alignment within five degrees of neutral and no apparent bone loss on radiographs were included. Twenty-one morphologic parameters of the distal femur and proximal tibia were measured on MR images. Correlation between the K-L grade and measured parameters and differences in measured parameters across the K-L grades and between the OA and control groups were evaluated.ResultsThe K-L grade was significantly correlated with multiple distal femur measurements including the posterior condylar angle (PCA), lateral epicondyle to posterior condylar cartilage (LEPC) length, medial epicondyle to posterior condylar cartilage (MEPC) length, medial epicondyle to distal cartilage (MEDC) length, medial tibial slope angle, femoral condylar cartilage height difference (FCHDc), and femoral condylar bone height difference (FCHDb) (P < 0.05). A significant difference was identified between the different K-L grades with regard to PCA, LEPC, MEPC, MEDC, and FCHDc (P < 0.05). There was no correlation between K-L grade and measured proximal tibial parameters.ConclusionsAmong knees without significant angular deformity, progression of knee OA is associated with a change in the morphology of the femoral condyles but not of the proximal tibia.     

Comparison of the clinical outcomes of transtibial pull-out repair for medial meniscus posterior root tear: Two simple stitches versus modified Mason-Allen suture

BackgroundTranstibial pullout repair of a medial meniscus posterior root tear (MMPRT) is a commonly used procedure, and several techniques have been reported. We hypothesised that pull-out repairs using two simple stitches (TSS) would have similar postoperative outcomes as those using the modified Mason-Allen suture with FasT-Fix (F-MMA). We aimed to investigate the clinical outcomes of these techniques, including the meniscal healing status and osteoarthritic change.MethodsThe data of 68 patients who underwent transtibial pull-out repair were retrospectively investigated. The patients were divided into two groups of 41 and 27 patients using F-MMA and TSS, respectively. The clinical outcomes were assessed preoperatively and at second-look arthroscopy (the mean period from surgery was one year) using the Knee injury and Osteoarthritis Outcome Score. The meniscal healing status, evaluated at second-look arthroscopy, was compared between the two groups. The cartilage damage was graded as per the classification of the International Cartilage Repair Society and compared at the primary surgery and second-look arthroscopy.ResultsBoth groups showed significant improvement in each clinical score. No significant difference was seen in the clinical outcome scores and the meniscal healing status between the two groups at second-look arthroscopy. Moreover, no significant progression of cartilage damage was observed in both groups. Fourteen patients in the F-MMA group developed a complication of suture bar failures postoperatively; however, there were no complications in the TSS group.ConclusionsThe TSS and F-MMA techniques showed favourable clinical outcomes and would be established as clinically useful techniques for the MMPRT treatment.     

Outcomes of trans-tibial posterior cruciate ligament reconstruction using a fovea landmark technique in relation to tunnel position and serial tunnel configuration

PurposeTo evaluate (1) the outcome of PCL reconstruction with tibial suspensory fixation using a fovea landmark technique based on the tunnel position and serial change of the tunnel configuration after trans-tibial PCL reconstruction, and (2) whether suspensory fixation has any harmful effect on the outcome.MethodsA total of 48 knees that underwent PCL reconstruction were included. The tunnel position was analyzed using CT. To analyze the tunnel configuration, the tunnel diameter, area, and volume were measured. To evaluate the outcome, pre- and postoperative International Knee Documentation Committee (IKDC) and Lysholm scores were analyzed. To evaluate stability, a side-to-side difference was evaluated using Telos stress radiographs.ResultsThe greatest configurational change occurred at the mid-portion of tibial tunnel. There was a correlation between stability and tibial tunnel mid-portion configurational change (p < 0.01). Important correlations were found between the tunnel position and serial tunnel configuration between high femoral tunnel and widest site of femoral tunnel and tibia aperture (p < 0.01 and 0.04, respectively). The diameter of widest site of tibia tunnel increased when the tibia tunnel center moved toward the posterior margin of the tibia (p = 0.02) and the percentage of femoral tunnel volume enlargement increased when the tibia tunnel center moved toward the medial edge of the PCL fovea (p = 0.02).ConclusionsA high femoral tunnel, medial tibial tunnel, and posterior tibial tunnel were related to the serial configurational change. A suspensory tibial fixation produced significant configurational change around the mid-portion of the tibial tunnel, and it induced a negative effect on stability.Level of Evidence: Level IV.     

Factors affecting articular cartilage repair after open-wedge high tibial osteotomy

Background

To evaluate the factors that affect articular cartilage repair after open-wedge high tibial osteotomy (OWHTO) and the relationship between regeneration of articular cartilage repair and clinical outcomes.

Under-correction of preoperative varus alignment does not lead to a difference in in-vivo bone loading in 3D-SPECT/CT compared to neutral alignment

BackgroundThe aim was to investigate the correlation of bone tracer uptake (BTU) in SPECT/CT and changes in coronal knee alignment after total knee arthroplasty (TKA). We questioned if undercorrection of preoperative varus alignment leads to a difference in BTU compared to neutral alignment.MethodsConsecutive 66 patients who received SPECT/CT before and after TKA were retrospectively included. Adjusted mechanical alignment was the alignment target. The alignment of the knee was measured on 3D-CT by selecting standardized landmarks. Maximum (mean ± SD) and relative BTU (ratio to the reference) were recorded using a previously validated localization scheme (p < 0.05).ResultsIn the native group, 20 knees were aligned (30.3%) in valgus (HKA > 181.5°), 12 (18.2%) in neutral (178.5°-181.5°) and 34 (51.5%) in varus (HKA < 178°). Overall TKA changed the alignment towards neutral. 48.5% remained in the same groups, whereas 50% of native valgus and 33% of varus knees changed to neutral after TKA. In native varus alignment mean BTU was significantly higher in some medial tibial and femoral regions (fem1ia (p = 0.010), fem1ip (p = 0.002), tib1a.mid (p = 0.005), tib1a.tray (p = 0.000), tib1p.tray (p = 0.000)); in native valgus alignment mean BTU was higher in the corresponding lateral tibial and femoral regions (fem2ip (p = 0.001), tib2a.tray (p = 0.011), tib2p.tray (p = 0.002)). After TKA, a significant decrease in femoral and tibial BTU (femoral preoperative BTU 1.64 +/-0.69; femoral postoperative BTU 0.95 +/-0.42; p = 0.000// tibial preoperative BTU 1.65 +/- 0.93; tibial postoperative BTU 1.16 +/- 0.48; p = 0.000) and an increase in patellar BTU was observed (p = 0.025). Native varus alignment correlated with a higher medial BTU decrease medially. Undercorrection of preoperative varus alignment showed no higher BTU after TKA.ConclusionPreoperative varus alignment correlated with a higher decrease in BTU in specific femoral and tibial medial regions. Preoperative valgus alignment correlated with a higher decrease in the corresponding lateral regions. Undercorrection of preoperative varus alignment did not lead to higher bone loading reflected by BTU after TKA.     

Lateral patellar tilt and its longitudinal association with patellofemoral osteoarthritis-related structural damage: Analysis of the osteoarthritis initiative data

BackgroundIncrease in lateral patellar tilt-(LPT) can cause increased pressure on the lateral facet of the knee and can lead to patellar or femoral cartilage damage and further osseous changes. This study aims to test the hypothesis whether there is an association between increased LPT and MRI-based patellofemoral osteoarthritis-(OA) features at baseline and their worsening over a 2-year follow-up in participants of the Osteoarthritis Initiative-(OAI).MethodsRecorded clinical and imaging data of 600 participants in the FNIH-OA biomarkers consortium was extracted from its database. The LPT-(as the angle between the longest patella diameter and posterior aspect of condyles) was measured using the axial knee MRI. Associations of LPT (every 5° increase) with MRI OA Knee Scoring-(MOAKS) for OA-related features, including cartilage and bone marrow lesions (BMLs) in addition to knee cartilage volume at baseline and their worsening after 2-year follow-up were assessed using regression models adjusted for several possible confounders.ResultsThe mean LPT angle in this sample was 8.84° ± 5.19. In baseline, higher LPT was associated with lower cartilage volumes and higher cartilage lesions and BMLs MOAKS scores in the lateral trochlear and patellar subregions. Over the follow-ups, subjects with higher LPT measures in the baseline showed higher odds of experiencing BML score worsening in the lateral trochlear subregion-(OR:1.25[1.01–1.56]) over the 2-year follow-ups.ConclusionsIncrease in LPT measures may be associated with OA-related features in the trochlear subregion. Therefore, aside from its use as an indicator of patellofemoral instability syndrome, LPT may be associated with longitudinal progression of patellofemoral OA.     

Patient specific instrumentation allow precise derotational correction of femoral and tibial torsional deformities

BackgroundRotational malalignment deformities of the lower limb in adults mostly arise from excessive femoral anteversion and/or excessive external tibial torsion. The aim of this study was to assess the correction accuracy of a patient specific cutting guides (PSCG) used in tibial and femoral correction for lower-limb torsional deformities.MethodsForty knees (32 patients) were included prospectively. All patients had patellofemoral pain or instability with torsional malalignment for which a proximal tibial (HTO) or distal femoral (DFO) or a double-level osteotomy (DLO) had been performed. Accuracy of the correction between the planned and the postoperative angular values including femoral anteversion, tibial torsion, coronal and sagittal alignment were assessed after tibial and/or femoral osteotomy.ResultsForty knees were included in this study. In cases of HTO, the correction accuracy obtained with PSCG was 1.3 ± 1.1° for tibial torsion (axial plane), 0.8 ± 0.7° for MPTA (coronal plane) and 0.8 ± 0.6° for PPTA (sagittal plane). In cases of DFO, the correction accuracy obtained with PSCG was 1.5 ± 1.4° for femoral anteversion (axial plane), 0.9 ± 0.9° for LDFA (coronal plane) and 0.9 ± 0.9° for PDFA (sagittal plane). The IKSG was improved from 58.0 ± 13.2° to 71.4 ± 10.9 (p = 0.04) and the IKSF from 50.2 ± 14.3 to 87.0 ± 6.9 (p < 0.001).ConclusionsUsing the PSCG for derotational osteotomy allows excellent correction accuracy in all the three planes for femoral and tibial torsional deformities associated with patellofemoral instability.Level of clinical evidence II, prospective cohort study.     

Combined deepening trochleoplasty and supracondylar external rotation osteotomy for recurrent patellar instability in patients with trochlear dysplasia and increased femoral antetorsion

BackgroundDeepening trochleoplasty has become a part of surgical management in patients with patellar instability and severe trochlear dysplasia. In addition, increased femoral antetorsion is treated most commonly by proximal femoral external rotation osteotomy.HypothesisDeepening trochleoplasty and supracondylar femoral external rotation osteotomy in combination improve patellar stability and function in patients presenting with recurrent patellar instability due to trochlear dysplasia and increased femoral antetorsion.Study designTherapeutic case series; Level IV.MethodsCombined deepening trochleoplasty and supracondylar external rotation osteotomy were performed in seven female patients (nine knees) with recurrent patellar instability. Trochlear dysplasia (Dejour classification) and increased femoral antetorsion (Murphy computed tomography (CT)-based measurement) were documented using magnetic resonance imaging and CT scans. Data were collected prospectively preoperatively, at 12 months, and at final follow-up. Complete data were available in 100% of cases. Clinical and functional outcomes were evaluated using the Kujala score and Tegner activity level scale.ResultsThe average age at the time of surgery was 22.2 years (range, 17–29 years). Preoperative MRI-based findings demonstrated in all patients significant trochlear dysplasia (B in two, C in five, and D in two knees). Femoral antetorsion was 37.8° on average (range, 27–51°). The mean follow-up was 2.1 years after surgery (range, 1–5.5 years). The median Kujala score was 41.2 preoperatively, rising to 83.1 at final follow-up (P = .015). The Tegner activity score improved from a mean preoperative score of 2.7 to a mean postoperative score of 6.0 (P = .020). Good patellar stability without positive apprehension sign was found in all patients. Poor outcome was associated with significant patellofemoral cartilage damage (grade IV) at the time of surgery. A total of 88.8% of patients were satisfied with the knee function at final follow-up. There were no postoperative complications.ConclusionThe combination of deepening trochleoplasty and supracondylar external rotation osteotomy performed in one step is an individually adapted surgical procedure for restoring both horizontal limb alignment and trochlear geometry. It improves patellar stability and yields good subjective and objective functional results in most cases. The condition of the cartilage at the time of surgery is crucial for the outcome with respect to the pain.     

Radiographic and clinical analysis of a Porous-coated metaphyseal cone for revision total Knee arthroplasty

BackgroundThe aim of this study was to evaluate the radiographic and clinical outcomes of a recently introduced metaphyseal cone system for revision TKA.Methods73 revision TKAs in 72 patients were retrospectively reviewed. All patients had a minimum of 2-year clinical follow-up (mean 34.1 months; range 24.0 to 50.3 months). 114 Metaphyseal cones (64 tibial and 50 femoral) of a single manufacturer were implanted. The most common indications for revision were aseptic loosening (56.9%), second stage reimplantation for periprosthetic joint infection (PJI; 26.4%), and instability (12.5%). All femoral and tibial stems were press-fit cementless stems.ResultsTen of 72 patients underwent re-revision: six for infection (8.3%), two for instability (2.8%), one (1.4%) for patellar tendon rupture and one (1.4%) for femoral component loosening (a cone was not utilized at index revision). Two patients had loose cones (one with an isolated tibial cone and one with both femoral and tibial cones) associated with loose implants but declined re-revision. Aseptic survivorship of our patient cohort free from any re-revision surgery was 95.9% at 2 years (95% CI 87.4–98.7%) and 96.5% of cones demonstrated radiographic evidence of osseointegration. At 2-years, the Knee Society Score (KSS) improved from a mean of 17.2 points preoperatively to 57.8 points (p <.0001).ConclusionsPorous-coated metaphyseal cones from this manufacturer demonstrate excellent aseptic survivorship and radiographic evidence of osseointegration similar to prior designs when used with cementless stems.     

Double-level osteotomy for severe varus osteoarthritic knees can prevent change in leg length and restore physiological joint geometry

BackgroundIt is unclear whether double-level osteotomy (DLO) combining closed-wedge osteotomy in the distal femur and open-wedge osteotomy in the proximal tibia deformity can prevent change in leg length and excessive coronal inclination of the tibial articular surface in surgical correction of the severe varus knee. The purpose of this study was to examine the postoperative change in leg length as well as radiological and clinical outcomes following DLO compared with the results obtained from knees undergoing isolated open-wedge high tibial osteotomy (OW-HTO).MethodsIn cases of severe varus knee deformity (hip–knee–ankle angle (HKA) > 10°) 29 patients undergoing DLO and 35 patients undergoing OW-HTO were included. If the predicted mechanical medial proximal tibial angle (mMPTA) was 95° or greater or the wedge size was 15 mm or greater in the surgical simulation, then DLO was considered as the surgical of option. In cases where these criteria were not met, OW-HTO was selected. All patients were followed up for a minimum of 2 years.ResultsThe changes in the length of the whole leg in the DLO and OW-HTO groups averaged 2.3 ± 4.8 mm and 9.3 ± 7.2 mm, respectively (P < 0.001). mMPTA of more than 95° was found in no knee in the DLO group.ConclusionsThis study showed that DLO could avoid leg length change and non-physiologic joint lines when performed in patients with varus HKA > 10°, and the predicted mMPTA was 95° or greater or the wedge size was 15 mm or greater in the surgical simulation.     

The distance between the tibial tunnel aperture and meniscal root attachment is correlated with meniscal healing status following transtibial pullout repair for medial meniscus posterior root tear

BackgroundTo investigate the relationship between tibial tunnel aperture location and postoperative meniscal healing.MethodsWe enrolled 25 patients (20 women and five men, mean age: 62.5 years) who underwent transtibial pullout repair for medial meniscus (MM) posterior root repair. The expected MM posterior root attachment center (AC) and tibial tunnel center (TC) were identified using three-dimensional computed tomography, and the minimum AC–TC distance was calculated. The meniscal healing status following transtibial pullout repair was assessed by second-look arthroscopy (mean postoperative period: 15 months) using a previously reported scoring system (meniscal healing score; range: 0–10). The association between AC–TC distance and meniscal healing score was investigated using univariate linear regression models. The optimal AC–TC distance cut-off for improved MM healing score (≥ 7) was determined using receiver operating characteristic analysis.ResultsThe AC–TC distance and meniscal healing score were significantly associated (y = − 0.42x + 9.48, R² = 0.342; P = 0.002), with the optimum AC–TC distance being 5.8 mm. This cut-off had a sensitivity of 100% and specificity of 53%.ConclusionsThis study demonstrates that AC–TC distance is significantly correlated with postoperative meniscal healing. Anatomical repair within 5.8 mm of the AC may result in improved meniscal healing.     

Clinical outcomes of medial meniscus posterior root repair: A midterm follow-up study

BackgroundTranstibial pullout repair of medial meniscus posterior root tears (MMPRTs) cannot prevent the progression of knee osteoarthritis. Conversions of knee arthroplasties are occasionally required following MMPRT repair. However, other knee-related surgical treatments following MMPRT repair are unclear. This study was aimed at investigating the midterm clinical outcomes and knee-related surgical events following MMPRT repair.MethodsPatients with MMPRT underwent pullout repair using FasT-Fix modified Mason-Allen (F-MMA) suturing with an all-inside meniscal repair device. Thirty-two patients with follow-up duration >2 years were enrolled. We assessed the clinical outcomes and postoperative surgical treatment of both knees.ResultsF-MMA pullout repair improved all clinical evaluation scores in patients with MMPRT at a mean follow-up of 36.1 months. Postoperative arthroscopic debridement was required for one patient. An additional MMPRT repair was performed in one patient on second-look arthroscopy. None of the patients required ipsilateral knee arthroplasty. In the contralateral knees, one pullout repair of a newly developed MMPRT and two knee arthroplasties were performed.ConclusionsThis study demonstrated that F-MMA pullout repair yielded satisfactory clinical outcomes. However, subsequent knee-related surgeries were observed in 6.3% of the pullout-repaired knees and 9.4% of the contralateral knees. Our results suggest that surgeons should be aware of the worsening and/or occurrence of contralateral knee joint disease, even when the postoperative clinical outcomes are satisfactory following MMPRT repair.Level of evidence: IV.     

Repair of articular cartilage and clinical outcome after osteotomy with microfracture or abrasion arthroplasty for medial gonarthrosis

This study compared the healing of articular cartilage and the clinical outcome after osteotomy with or without marrow stimulation microfracture or abrasion arthroplasty for osteoarthritis of the knee. Patients with osteoarthritis of the medial compartment of the knee were divided into a group undergoing high tibial osteotomy alone (HTO group: 37 knees), a group undergoing osteotomy plus microfracture (MF group: 26 knees), and a group undergoing osteotomy plus abrasion arthroplasty (AA group: 51 knees). The extent of cartilage repair was compared at 1 year after surgery by arthroscopy with reference to Outerbridge's classification, while the clinical outcome was compared at 1, 3, and 5 years postoperatively. Second-look arthroscopy revealed better repair of the femoral condylar cartilage in the AA group than the HTO group (p < 0.0005) or MF group (p < 0.01), with no difference between the HTO and MF groups. Repair of the tibial condylar cartilage was also better in the AA group than the HTO group (p < 0.005), but there was no difference between the AA and MF groups or the MF and HTO groups. There were no differences of the clinical outcome between the three groups. In conclusion, repair of articular cartilage at 1 year postoperatively was accelerated by abrasion arthroplasty, but not by microfracture. However, there was no difference of the clinical outcome within 5 years after surgery, so the clinical utility of marrow stimulation techniques was not apparent in this study.     

Human umbilical cord-blood-derived mesenchymal stem cell can improve the clinical outcome and Joint space width after high tibial osteotomy

BackgroundThere is limited study about the human umbilical cord-blood derived mesenchymal stem cell (hUCB-MSC) cartilage regeneration procedures combined with high tibial osteotomy (HTO). We compared the clinical and radiological results of hUCB-MSC cartilage regeneration procedures combined with HTO to those of microfracture with HTO.MethodsFrom August 2017 to December 2018, HTO patients with International Cartilage Regeneration and Joint Preservation Society (ICRS) grade IV cartilage defects over 200 mm² on medial femoral condyle (MFC) were enrolled. For comparison, all participants were divided into two groups: those who had undergone an hUCB-MSC induced cartilage regeneration procedure (group MSC) and those with microfractures only (group C, controls). Clinically, Hospital for Special Surgery (HSS), International Knee Documentation Committee (IKDC), and Lysholm scores were evaluated post-operatively at 18 months. Radiologically, mechanical axis (MA) and joint space width (JSW) were evaluated.ResultsA total of 100 knees were enrolled (43 in group MSC, 57 in group C). The IKDC score in group MSC (69) was better than that in group C (62; P < 0.05). The JSW increment in the MSC group (0.6 mm) was more than that in group C (0.1 mm; P < 0.05). No patient developed nonunion, correction loss, or arthroplasty conversion.ConclusionhUCB-MSCs can improve clinical outcome and JSW better than microfracture only in HTO patients.     

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

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

Individual and cumulative measures of knee joint load associate with T2 relaxation times of knee cartilage in young,uninjured individuals: A pilot study

BackgroundArticular cartilage structure and chondrocyte health are sensitive and reliant on dynamic joint loading during activities. The purpose of this pilot study was to determine the association between measures of individual and cumulative knee joint loading with T2 relaxation times in the knee cartilage of young individuals without knee injury.MethodsTwelve participants (17–30 years old) without history of knee injury or surgery completed MRI, physical activity (PA), and biomechanical gait testing. T2 relaxation times were calculated in the cartilage within the patella and lateral and medial compartments. Accelerometry was used to measure mean daily step counts, minutes of PA, and % sedentary time over 7 days. Vertical ground reaction force, external knee joint moments and peak knee flexion angle were measured during stance phase of gait using three-dimensional motion capture. Cumulative knee joint loading was calculated as daily step count by external knee joint moment impulse. The relationship between measures of knee joint loading and T2 relaxation times was assessed using Pearson correlations.ResultsHigher T2 relaxation times in the femoral and tibial cartilage were consistently correlated to greater body mass, daily step counts, moderate and vigorous PA, and peak knee joint moments (r = 0.10–0.84). Greater cumulative knee flexion and adduction loading was associated with higher T2 relaxation times in the femoral and tibial cartilage (r = 0.16–0.65).ConclusionPreliminary findings suggest that individual loading factors and cumulative knee joint loading are associated with higher T2 relaxation times in the articular cartilage of young, healthy knees.