Posterior Knee Research Articles

Dynamic Taping Improves Landing Biomechanics in Young Volleyball Athletes.

Poor landing biomechanics such as hip adduction, internal rotation, and knee valgus have been recognized as modifiable risk factors of anterior cruciate ligament (ACL) injury. Dynamic taping is a newly developed technique with better elasticity and extensibility, which could change the landing biomechanics. The purpose of this study was to identify whether dynamic taping could improve lower limb biomechanics in athletes. Forty-two high school volleyball athletes (21 males and 21 females) participated in the study. Biomechanical properties, including the landing error scoring system (LESS) and anterior–posterior knee laxity, were evaluated before and after the application of dynamic tape while athletes performed the jump-landing task. As a result, we found that dynamic tape significantly reduced the faulty landing strategy by an average of 0.64 errors in all volleyball athletes. The effect induced by dynamic tape was more prominent in female athletes and high-risk athletes (1.1 errors). Furthermore, the application of dynamic tape improved anterior–posterior knee laxity, especially in female athletes (p < 0.001). In conclusion, we found that dynamic tape provided a short-term, passive, and clinically significant means to normalize inadequate biomechanics during landing in athlete groups, which could have a protective effect and further alleviate the risk of ACL injury.

Quadriceps tendon autograft for primary anterior cruciate ligament reconstruction show comparable clinical, functional, and patient-reported outcome measures, but lower donor-site morbidity compared with hamstring tendon autograft: A matched-pairs study with a mean follow-up of 6.5 ​years

ObjectivesTo compare clinical and functional outcomes of patients after primary anterior cruciate ligament reconstruction (ACLR) using quadriceps tendon- (QT-A) and hamstring tendon (HT-A) autograft with a minimum follow-up (FU) of 5 years. MethodsBetween 2010 and 2014, all patients undergoing ACLR were recorded in a prospectively administered database. All patients with primary, isolated QT-A ACLR and without any concomitant injuries or high grade of osteoarthritis were extracted from the database and matched to patients treated with HT-A. Re-rupture rates, anterior–posterior (ap) knee laxity, single-leg hop test (SLHT) performance, distal thigh circumference (DTC) and patient-reported outcome measures (PROMs) were recorded. Between group comparisons were performed using chi-square-, independent-samples T- or Mann–Whitney–U tests. Results45 QT-A patients were matched to 45 HT-A patients (n ​= ​90). The mean FU was 78.9 ​± ​13.6 months. 18 patients (20.0%/QT-A: N ​= ​8, 17.8%; HT-A: n ​= ​10, 22.2%; p ​= ​.60) sustained a graft rupture and 17 subjects (18.9%/QT-A: n ​= ​9, 20.0%; HT-A: n ​= ​8, 17.8%; p ​= ​.79) suffered a contralateral ACL injury. In high active patients (Tegner activity level ≥ 7) rerupture rates increased to 37.5% (HT-A) and 22.2% (QT-A; p ​= ​.32), respectively. Patients with graft failure did not differ between both groups in terms of mean age at surgery (QT-A: 26.5 ​± ​11.6 years, HT-A: 23.3 ​± ​9.5 years, p ​= ​.63) or graft thickness (mean graft square area: QT-A: 43.6 ​± ​4.7 mm2, HT-A: 48.1 ​± ​7.9 mm2, p ​= ​.27). No statistical between-group differences were found in ap knee laxity side-to-side (SSD) measurements (QT-A: 1.9 ​± ​1.2 ​mm, HT-A: 2.1 ​± ​1.5 ​mm; p ​= ​.60), subjective IKDC- (QT-A: 93.8 ​± ​6.8, HT-A: 91.2 ​± ​7.8, p ​= ​.17), Lysholm- (QT-A 91.9 ​± ​7.2, HT-A: 91.5 ​± ​9.7, p ​= ​.75) or any of the five subscales of the KOOS score (all p ​> ​.05). Furthermore, Tegner activity level (QT-A: 6(1.5), HT-A: 6(2), p ​= ​.62), VAS for pain (QT-A: 0.5 ​± ​0.9, HT-A: 0.6 ​± ​1.0, p ​= ​.64), Shelbourne–Trumper score (QT-A: 96.5 ​± ​5.6, HT-A: 95.2 ​± ​8.2, p ​= ​.50), Patient and Observer Scar -Assessment scale (POSAS) (QT-A: 9.4 ​± ​3.2, HT-A: 10.7 ​± ​4.9, p ​= ​.24), SSD-DTC (QT-A: 0.5 ​± ​0.5, HT.- A: 0.5 ​± ​0.6, p ​= ​.97), return to sports rates (QT-A: 82.1%, HT-A: 86.7%) and SLHT (QT -A: 95.9 ​± ​3.8%, HT-A: 93.7 ​± ​7.0%) did not differ between groups. Donor-site morbidity (HT-A n ​= ​14, 46.7%; QT-A n ​= ​3, 11.5%; p ​= ​.008) was statistically significantly lower in the QT-A group. Five patients (11.1%) of the HT-group and three patients (6.7%) in the QT-group required revision surgery (p ​= ​.29). ConclusionPatient-reported outcome measures, knee laxity, functional testing results and re-rupture rates are similar between patients treated with QT- and HT- autografts. However, patients with QT-autograft have a smaller tibial postoperative scar length and lower postoperative donor-site morbidity. There is a tendency towards higher graft rupture rates in highly active patients treated with HT autograft. Level of evidenceII.

Anti-arthritic effect of Distemonanthus benthamianus extracts against rheumatoid arthritis in rats

Objective: To evaluate the anti-arthritic effect of aqueous and methanolic extracts of Distemonanthus benthamianus. Methods: Monoarthritis was induced by an injection of 0.3 mL zymosan A (0.9% NaCl, v/v) in the right posterior knee joints of rats. Then, joint diameter and pain threshold were determined. Polyarthritis was induced by an intracaudal injection of complete Freund’s adjuvant and rats were treated from day 14 post 1st complete Freund’s adjuvant injection until 28 day. The clinical, hematological, biochemical and oxidative stress parameters were evaluated. In addition, histological analysis of the knee joint was perfomed in both tests. Results: The aqueous and methanolic extracts of Distemonanthus benthamianus at a dose of 500 mg/kg ameliorated zymosan A-induced monoarthritis, as evidenced by reduced joint diameter, increased pain threshold, as well as improved joint architecture. In addition, both extracts of Distemonanthus benthamianus markedly increased body weight and pain threshold, while reducing paw edema in polyarthritic rats. They also led to a marked decrease in platelets and white blood cells (P&lt;0.05), as well as a significant increase in red blood cells, hemoglobin and hematocrit (P&lt;0.05). The aqueous and methanolic extracts of Distemonanthus benthamianus significantly reduced alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase activities, while increasing serum protein levels (P&lt;0.05) with no significant variation in creatinine level. Moreover, both extracts increased catalase and glutathione activities (P&lt;0.05), and inhibited malondialdehyde and nitric oxide production (P&lt;0.01 and P&lt;0.001) in the liver and kidneys. Histological analysis of the joints showed that both extracts triggered tissue reparation. Conclusions: Distemonanthus benthamianus could be used as a potential candidate in the treatment of rheumatoid arthritis.

The Relationship Between Posterior Tibial Slope and Knee Range of Movements in Posterior Stabilized Total Knee Replacement: A Navigation-Assisted Analysis of 120 Cases.

Background Posterior tibial slope (PTS) is one of the factors that determine the postoperative range of movement (ROM) in total knee replacement (TKR). While biomechanical factors influencing ROM such as PTS, soft-tissue balancing, and choice of implants are surgeon-dependent, non-biomechanical factors such as physiotherapy and pain are subjective and beyond the surgeon's control. Using navigation, we avoided these factors and objectively correlated the difference in PTS with ROM. Methodology A total of 120 cases of posteriorly stabilized (PS) TKR were included. The X-ray-measured difference in PTS was compared to the corresponding change in the ROM intraoperatively using the TKR navigation system. Based on the change in PTS, the cases were classified into three groups, and the intergroup variability of mean postoperative ROM, mediolateral laxity difference (MLD), and residual flexion (RF) was calculated. Results An average MLD of 1.39 mm in extension and 1.79 mm in flexion and an average RF of 3.18 degrees were seen. This uniformity neutralizes the effects of these factors on the ROM. The mean difference in the PTS in the three groups was 4.45, 10.76, and 17.98 degrees, and the mean change in the ROM was 3.07, 1.47, and 2.84 degrees, respectively. There was no statistically significant change in ROM with that of change in PTS. Conclusions In our study, it was shown statistically that the coronal and sagittal planes were uniformly balanced using navigation assistance, and the PTS and the postoperative ROM were the only variables. The correlated results showed that a change in the PTS does not affect the postoperative ROM in PS TKR using the implant system used in our study.

Impact of a Digital Balancing Tool on Femur and Tibial First Total Knee Arthroplasty: A Prospective Nonrandomized Controlled Trial

BackgroundRecent developments in intra-operative sensor technology provide surgeons with predictive and real-time feedback on joint balance. It remains unknown, however, whether these technologies are better suited to femur-first or tibia-first workflows. This study investigates the balance accuracy, precision and early patient outcomes between the femur-first and tibial-first workflows using a digital gap-balancing tool. MethodsOne-hundred six patients had posterior cruciate ligament sacrificing total knee arthroplasty using a digital joint tensioner. The participants were divided into 4 groups with different visibility to balance data 1) Femur-first blinded data, 2) Femur-first not blinded data, 3) Tibia-first blinded data, 4) Tibia-first not blinded data with predictive balancing. Knee Injury and Osteoarthritis Outcome Score and University of California at Los Angeles activity level were recorded at 1-year. ResultsGroup 4 reported less midflexion imbalance (40°) compared to all other groups (1: 1.5 mm, 2: 1.7 mm, 3: 1.6 mm, 4: 1.0 mm, P < .031) and reduced variance compared to all other groups at 40° and 90° (P < .012), resulting in an increased frequency of joints balanced within 2 mm throughout flexion in group 4 (1: 69%, 2: 65%, 3: 67%, 4: 91%, P < .006). No differences were found between 3-month, 6-month, or 1-year outcome scores between technique. ConclusionsImprovements in balance were observed in midflexion instability and balance variability throughout flexion when a tibia-first approach in combination with a digital balancing tool was used. The combination of a digital balancing tool and a tibia-first approach allowed a target joint balance to be achieved more accurately compared to a non-sensor augmented or femur-first approach.

IPACK (Interspace between the Popliteal Artery and the Capsule of the Posterior Knee) Block Combined with SACB (Single Adductor Canal Block) VersusSACB for Analgesia after Total Knee Arthroplasty

To evaluate the combination of the infiltration between the popliteal artery and the posterior capsule of the knee (iPACK) block and single adductor canal block (SACB) versus SACB for motor-sparing knee analgesia effects after total knee arthroplasty (TKA). PubMed, Ovid, Cochrane Library, and other databases were searched from the inception to January 2021. Randomized controlled trials (RCTs) comparing patients receiving iPACK plus SACB with patients receiving SACB after TKA were included. The included studies were assessed by two reviewers according to the Cochrane risk of bias criteria. Meta-analysis was performed with STATA 13.0 software, the risk ratios (RR) and mean differences (MD) were used to compare dichotomous and continuous variables. The primary outcome was ambulation pain and secondary outcomes were rest pain, opioid consumption, function ability, clinical outcomes, and complications. Seven RCTs (304 knees in iPACK + SACB group; 305 knees in SACB group) were included. The follow-up periods ranged from 2 days to 3 months. Pooled data indicated lower pain scores at ambulation (p < 0.0001) for iPACK + SACB. When comparing the pain scores of subgroups analyzed at specific periods, lower scores in subgroups within 12h (at rest and ambulation) and after 48h (at ambulation) were observed in the iPACK + SACB group. Analysis demonstrated greater reduction in morphine consumption (p=0.007) in the iPACK + SACB group. The iPACK + SACB group is also superior to the SACB group regarding function ability, which included range of motion (ROM) (p=0.001), time up to go (TUG) test (p=0.030), and ambulation distance (p < 0.0001). No difference was found in clinical outcomes or complications. With the iPACK added to SACB, pain scores, morphine consumption, functional ability were improved. Additional high-quality studies are required to further address this topic.

Arthroscopic Decompression of a Posterior Knee Cyst Causing Vascular Compression

Intra-articular ganglion cysts in the knee large enough to cause neurovascular claudication are rare entities only identified in singular case reports. The severity of claudication can cause debilitating symptoms and pain to previously highly functional and asymptomatic patients. Total knee arthroplasty has been described to treat these cysts in elderly patients with osteoarthritis, although this treatment pathway may not appeal to patients without antecedent pain and high activity levels. This surgical report will detail a reproducible method of arthroscopic decompression of posterior, intra-articular cysts to relieve vascular claudication by highlighting technical pearls in navigating posterior knee arthroscopy.

Can tibia-first total knee arthroplasty using computer-assisted system improve anterior and posterior knee stability?

Total knee arthroplasty (TKA) is a widely performed procedure to alleviate pain and restore function of patients with end-stage knee osteoarthritis. The study aim was to determine if tibia-first (TF) total knee arthroplasty (TKA) using a novel computer-assisted surgery (CAS) system can yield better anterior and posterior (AP) knee stability. Patients with knee osteoarthritis with obvious varus knee who met the indication for and underwent TKA from May 2019 to November 2020 were included. Forty-one measured resection (MR)-TKAs and 32 TF-TKAs were compared. The varus-valgus ligament balance and joint tension at a joint center-gap setting equal to the tibial-baseplate thickness were measured, and appropriate polyethylene inserts with 0∘, 30∘, 45∘, 60∘, 90∘, and 120∘ of knee flexion were placed. A Kneelax 3 arthrometer was used to measure knee AP laxity in the postoperative anesthetized patients with 30∘ and 90∘ of knee flexion. The horizontal gap balance was significantly closer in the TF-TKA group than the MR-TKA group for 0∘, 30∘, 45∘, and 60∘ of knee flexion. In contrast, no significant differences were observed for 90∘ and 120∘ of knee flexion. No significant differences in joint-gap tensions among all knee-flexion angles were observed. Translation was significantly smaller in the TF-TKA group than the MR-TKA group for AP laxity with 30∘ of knee flexion (8.8 ± 2.9 mm vs. 10.7 ± 3.1 mm, P= 0.0079). In contrast, no significant AP laxity was observed with 90∘ of knee flexion (7.2 ± 2.8 mm vs. 7.2 ± 3.5 mm). TF-TKA using a novel CAS system provided better AP knee stability with close to horizontal gap balances.

Treatment Of A Cruciate Associated Cyst In A Collegiate Rower

HISTORY: A 20 year old female collegiate rower presents to the training room with gradual onset of right knee pain and decreased range of motion. She is unable to identify specific time or mechanism of injury. Her pain is in the posterior knee and worsens with knee flexion and extension against resistance. She particularly notices this while on the ergometer and has had to completely halt her training regimen. She has no history of prior knee injury. PHYSICAL EXAMINATION: The right knee is without obvious deformity, erythema or effusion. There is tenderness to palpation of the popliteal space, there is no palpable lesion. Range of motion is limited at full flexion. She has pain with full flexion and extension against resistance. Lachman is intact though produces pain. Posterior drawer and valgus/varus testing are intact. The remainder of the knee exam is unremarkable. DIFFERENTIAL DIAGNOSIS: 1. ACL sprain. 2. Popliteal cyst 3. Meniscus injury TEST AND RESULTS: Point of care US: No effusion. No Baker's cyst. Xray right knee: No osseous abnormalities. MRI right knee: Cystic lesion centered at the junction of the posteromedial ACL and lateral meniscal root bundles FINAL/WORKING DIAGNOSIS: Ganglion cyst associated with the ACL/meniscus. TREATMENT AND OUTCOMES: The athlete worked closely with her ATs on a rehab protocol with no improvement in symptoms. Injection therapy with corticosteroid versus arthroscopic intervention were discussed. Ultimately, she was taken to the operating room for successful arthroscopic debridement of the cyst. She was able to return to rowing within weeks of surgery and did not miss any competition.

Knee Injury-Baseball

HISTORY: A 19yo male college baseball pitcher presented for acute onset left medial knee pain after attempting to carry a couch, at which time he twisted the knee into a valgus position and felt a painful pop. He had mild difficulty with weight bearing and swelling. He questioned whether he may have dislocated the kneecap with spontaneous reduction. He denied associated bruising, instability, hip or back pain. He denied prior knee injury. He did report mild chronic groin pain during pitching which was unchanged. PHYSICAL EXAMINATION: There was mild effusion about the left knee, with tenderness at the medial joint line and near the proximal origin of the MCL. There was pain with valgus stress, without clear laxity. Varus stress was non-provocative. Anterior and posterior drawer test were limited secondary to guarding. Lachman's test was equivocal. McMurray's test was positive for pain. Patellar apprehension was positive. Patellar grind was negative. Straight leg test was negative. Distal neurovascular exam was grossly intact. DIFFERENTIAL DIAGNOSIS: Lateral patellar dislocation/subluxation. ACL or MCL sprain/tear. Traumatic medial meniscus tear. Osteochondral lesion of the medial femoral condyle. Muscle or tendon sprain/tear. TEST AND RESULTS: Left knee X-ray was negative for fracture and showed normal alignment. Left knee MRI revealed nonspecific edema throughout the deep soft tissues of the posterior distal thigh and knee, most pronounced along the posteromedial aspect of the distal femoral metaphysis near the insertion of the adductor magnus tendon. Findings were suggestive of acute on chronic partial tearing/avulsion injury of the distal adductor magnus with an adjacent focus of mineralization consistent with underlying calcific tendinosis. The cruciate and collateral ligaments were intact. There were no findings suggestive of transient lateral patellar dislocation. FINAL WORKING DIAGNOSIS: Calcific tendinosis of the adductor magnus tendon, with superimposed traumatic avulsion injury/partial tearing TREATMENT AND OUTCOMES: The patient was allowed to weight bear as tolerated but was instructed to abstain from lower body exercise for 4 weeks. NSAIDs were used for pain relief as needed. He was referred to PT at 4 weeks with a focus on pitching mechanics.

Is Highly Cross-Linked Polyethylene Safe for Use in High-Flexion Posterior Stabilized Total Knee Arthroplasty?

BackgroundApplication of highly cross-linked polyethylene (HXLPE) to a posterior cruciate-substituting total knee arthroplasty (TKA) might add the risk of fracture and failure of the tibial polyethylene insert. The purpose of this study is to evaluate the long-term (up to 19 years) clinical and radiographic results of posterior cruciate-substituting TKAs with HXLPE or conventional polyethylene. MethodsThis study analyzed the results of 1,217 patients (444 men and 773 women; mean age of 65 ± 7 years, range, 31-85) (2,434 knees) who had received a NexGen LPS-Flex prosthesis with a conventional tibial insert in one knee and the same prosthesis with an HXLPE tibial insert in the contralateral knee. The mean duration of follow-up was 17 years (range, 15-19). ResultsThe 2 groups did not differ significantly (P > .05) with regard to the clinical and radiographic results. No knee in either group had a fracture of the tibial polyethylene post or failure of the locking mechanism of the tibial polyethylene insert or osteolysis. Twenty-eight knees (2.3%) in the HXLPE group and 26 knees (2.1%) in the conventional polyethylene group were revised. The estimated survival rate at 17 years was 97.7% in the HXLPE group and 97.9% in the conventional polyethylene group. ConclusionThe data suggest that clinical and radiographic findings at a mean of 17 years after posterior cruciate-substituting TKA are the same for patients treated with HXLPE and those treated with conventional polyethylene.

Influence of posterior tibial slope on sagittal knee alignment with comparing contralateral knees of anterior cruciate ligament injured patients to healthy knees

Posterior tibial slope (PTS) has been known to contribute to anterior–posterior knee stability and play an essential biomechanical role in knee kinematics. This study aimed to investigate the effect of PTS on single-leg standing sagittal knee alignment of the intact knee. This study included 100 patients with unilateral ACL injury knee (ACL injury group, 53 patients) or with the normal knee (control group, 47 patients). The single-leg standing sagittal alignment of the unaffected knees of the ACL injury group and normal knees of the control group were assessed radiographically with the following parameters: knee extension angle (EXT), PTS, PTS to the horizontal line (PTS-H), femoral shaft anterior tilt to the vertical axis (FAT), and tibial shaft anterior tilt to the vertical axis (TAT). PTS was negatively correlated with EXT and positively correlated with TAT. EXT was significantly larger in the ACL injury group, whereas TAT was smaller in the ACL injury group. Patients with larger PTS tend to stand with a higher knee flexion angle by tilting the tibia anteriorly, possibly reducing tibial shear force. Patients with ACL injury tend to stand with larger EXT, i.e., there is less preventive alignment to minimize the tibial shear force.

Distance to the Neurovascular Bundle for Iliotibial Band Graft Passage During Anterior Cruciate Ligament Reconstruction: A Pediatric Cadaveric Study.

Background:The Micheli technique for anterior cruciate ligament (ACL) reconstruction (ACLR) has proven to be a reliable method with a minimal risk for growth disturbance among skeletally immature patients.Purposes:To evaluate the Micheli technique of iliotibial band (ITB) graft passage for ACLR using cadaveric knee models and to measure the distance between the surgical instrument tip and the neurovascular bundle in the posterior knee joint: specifically, the peroneal nerve, tibial nerve, and popliteal artery.Study Design:Descriptive laboratory study.Methods:Gross dissection was performed on 17 pediatric cadaveric knees (12 male and 5 female) aged between 4 and 12 years. To simulate ITB graft passage, we passed a curved-tip hemostat clamp through the posterior capsule, with the knee flexed from 90° to 100°. Next, clinical photographs were taken, and digital imaging software was used to measure the distance in centimeters from the clamp tip to each respective neurovascular structure.Results:The mean distances from the clamp tip to the tibial nerve, popliteal artery, and peroneal nerve were 0.875 cm (range, 0.468-1.737 cm), 0.968 cm (range, 0.312-1.819 cm), and 1.149 cm (range, 0.202-2.409 cm), respectively. Mean values were further calculated for age groups of ≤8, 9-10, and 11-12 years. The mean distance from the clamp tip to the peroneal nerve was 1.400 cm larger for 11- to 12-year-old specimens than for ≤8-year-old specimens (95% CI, 0.6-2.2 cm; P = .005).Conclusion:The neurovascular structures in the posterior knee were in close proximity to the path of graft passage, with distances <1 cm in many specimens in this study. When passing the graft through the knee for an over-the-top position, surgeons should consider these small distances between the path of graft passage and critical neurovascular structures.Clinical Relevance:As the incidence of ACL tears is continuously increasing within the pediatric population, there are a larger number of ACLR procedures being performed. Although neurovascular injuries during ACLR are rare, this study clarifies the close proximity of neurovascular structures during ITB graft passage using the Micheli technique of ACLR.

Perineural Methylprednisolone Depot Formulation Decreases Opioid Consumption After Total Knee Arthroplasty.

PurposeOpioid consumption after total knee arthroplasty (TKA) remains a challenge with single injection nerve blocks even with common local anesthetic adjuvants dexamethasone (DEX). This study aimed to investigate the effects of adding methylprednisolone acetate (MPA) to adductor canal blocks (ACB) and interspace between the popliteal artery and capsule of the posterior knee (iPACK) blocks on postoperative opioid consumption.MethodsA retrospective analysis was conducted on 100 consecutive TKA patients equally assigned into two groups, with one group receiving DEX through ACB and iPACK block and the other group receiving DEX and methylprednisolone acetate (DEX/MPA) through the same nerve blocks. The primary outcome was cumulative opioid consumption (oral milligram morphine equivalent, OME) during hospitalization for up to three days. Secondary outcomes included daily opioid consumption, highest rest and active pain scores, prosthetic knee joint active range of motion (AROM), laboratory studies including fasting serum glucose (FSG) and white blood cell count (WBC) on each postoperative day (POD), and length of hospital stay.ResultsCumulative opioid consumption was significantly lower in the DEX/MPA group vs DEX group (median difference (95% CI) = −45.3 (−80.5 to −10), P = 0.011). The highest rest and active pain scores were both significantly lower in the DEX/MPA group than in DEX group on POD 2 (least square mean difference (95% CI) = −1.3 (−2.3 to −0.4), P = 0.005 and −0.9 (−1.8 to −0.1), P = 0.031, respectively). Except on POD 1, FSG values were significantly lower in the DEX/MPA group (median difference (95% CI) = −22.5 (−36 to −8.9), P = 0.001). AROM, WBC, and length of stay were comparable between both groups.ConclusionCompared to perineural DEX alone, the addition of MPA further decreases postoperative opioid consumption without clinically significant changes on FSG and WBC.Level of EvidenceIII.

MUCOID DEGENERATION OF THE ANTERIOR CRUCIATE LIGAMENT: REVIEW OF THE LITERATURE

Background:The cases of mucoid degeneration initially described in the 1950s mainly concerned the cardiovascular system. In 1976 Ewing et al (24) reported the first case of mucoid degeneration of striated muscle in the limbs. In 1999 Kumar et al (2) described the first case of mucoid degeneration of the anterior cruciate ligament of the knee Aims: to study the clinical and radiographic semiology of this pathology and the possible therapeutical alternatives. Patients/Methods: Retrospective studies with a case series. The number of cases in each study is greater than or equal to 10 cases.And alldiagnosis of mucoid degeneration of the anterior cruciate ligament is authenticated by magnetic resonance imaging of the knee with Location of the lesion in the anterior cruciate ligament. Results: Our search strategy yielded 42 articles. The abstracts were reviewed to identify articles appropriate for our study resulting in the identification of 18 articles. Ten studies were excluded because they had a limited number of cases (9 articles about one case and 1 article about 5 cases). Another article (17) was also excluded because it included a comparative study with control groups of patients with normal MRI and arthroscopy. Seven articles meeting the inclusion criteria were retained for the final analysis. Conclusions: Mucoid degeneration of the anterior cruciate ligament of the knee is often misunderstood and confused with a partial rupture of the ACL. Its diagnosis must be suspected in front of a stereotyped clinical picture of unusual posterior knee pain and a limitation of flexion. The symptomatology sometimes takes atypical forms because of the frequently associated meniscal and cartilage lesions.

Systematic study of single-cell isolation from musculoskeletal tissues for single-sell sequencing

BackgroundThe single-cell platform provided revolutionary way to study cellular biology. Technologically, a sophistic protocol of isolating qualified single cells would be key to deliver to single-cell platform, which requires high cell viability, high cell yield and low content of cell aggregates or doublets. For musculoskeletal tissues, like bone, cartilage, nucleus pulposus and tendons, as well as their pathological state, which are tense and dense, it’s full of challenge to efficiently and rapidly prepare qualified single-cell suspension. Conventionally, enzymatic dissociation methods were wildly used but lack of quality control. In the present study, we designed the rapid cycling enzymatic processing method using tissue-specific enzyme cocktail to treat different human pathological musculoskeletal tissues, including degenerated nucleus pulposus (NP), ossifying posterior longitudinal ligament (OPLL) and knee articular cartilage (AC) with osteoarthritis aiming to rapidly and efficiently harvest qualified single-cell suspensions for single-cell RNA-sequencing (scRNA-seq).ResultsWe harvested highly qualified single-cell suspensions from NP and OPLL with sufficient cell numbers and high cell viability using the rapid cycling enzymatic processing method, which significantly increased the cell viability compared with the conventional long-time continuous digestion group (P < 0.05). Bioanalyzer trace showed expected cDNA size distribution of the scRNA-seq library and a clear separation of cellular barcodes from background partitions were verified by the barcode-rank plot after sequencing. T-SNE visualization revealed highly heterogeneous cell subsets in NP and OPLL. Unfortunately, we failed to obtain eligible samples from articular cartilage due to low cell viability and excessive cell aggregates and doublets.ConclusionsIn conclusion, using the rapid cycling enzymatic processing method, we provided thorough protocols for preparing single-cell suspensions from human musculoskeletal tissues, which was timesaving, efficient and protective to cell viability. The strategy would greatly guarantee the cell heterogeneity, which is critical for scRNA-seq data analysis. The protocol to treat human OA articular cartilage should be further improved.

No Benefits of Adding Dexmedetomidine, Ketamine, Dexamethasone, and Nerve Blocks to an Established Multimodal Analgesic Regimen after Total Knee Arthroplasty.

An optimal opioid-sparing multimodal analgesic regimen to treat severe pain can enhance recovery after total knee arthroplasty. The hypothesis was that adding five recently described intravenous and regional interventions to multimodal analgesic regimen can further reduce opioid consumption. In a double-blinded fashion, 78 patients undergoing elective total knee arthroplasty were randomized to either (1) a control group (n = 39) that received spinal anesthesia with intrathecal morphine, periarticular local anesthesia infiltration, intravenous dexamethasone, and a single injection adductor canal block or (2) a study group (n = 39) that received the same set of analgesic treatments plus five additional interventions: local anesthetic infiltration between the popliteal artery and capsule of the posterior knee, intraoperative intravenous dexmedetomidine and ketamine, and postoperatively, one additional intravenous dexamethasone bolus and two additional adductor canal block injections. The primary outcome measure was 24-h cumulative opioid consumption after surgery and secondary outcomes were other analgesics, patient recovery, functional outcomes, and adverse events. Opioid consumption was not different between groups at 24 h (oral morphine equivalents, mean ± SD; study: 23.7 ± 18.0 mg vs. control: 29.3 ± 18.7 mg; mean difference [95% CI], -5.6 mg [-2.7 to 13.9]; P = 0.189) and all other time points after surgery. There were no major differences in pain scores, quality of recovery, or time to reach rehabilitation milestones. Hypotensive episodes occurred more frequently in the study group (25 of 39 [64.1%] vs. 13 of 39 [33.3%]; P = 0.010). In the presence of periarticular local anesthesia infiltration, intrathecal morphine, single-shot adductor canal block and dexamethasone, the addition of five analgesic interventions-local anesthetic infiltration between the popliteal artery and capsule of the posterior knee, intravenous dexmedetomidine, intravenous ketamine, an additional intravenous dexamethasone dose, and repeated adductor canal block injections-failed to further reduce opioid consumption or pain scores or to improve functional outcomes after total knee arthroplasty.

Chronic Irreducible Knee Dislocations: Outcomes following Open Reduction and Reconstructive Surgery.

The management of unreduced knee dislocations who present late is challenging. The aim of this study was to determine the clinical, radiological, and functional outcomes following open reduction and reconstructive surgery for chronic irreducible knee dislocations. This retrospective study analyzed prospectively collected data of patients with an unreduced fixed anterior or posterior knee dislocation of 1 to 6 months' duration, treated with open reduction, hinged external fixator application, and ligament reconstruction who had a minimum 2-year follow-up. Patients were classified based on presence of prior periarticular surgery and direction of dislocation. Data on pre- and posttreatment clinical, radiological, and functional scores were analyzed. A total of 21 patients (age range: 19-43 years) fulfilled all inclusion criteria. These included 13 missed dislocations and 8 neglected postoperative dislocations. There were 18 posterior and 3 anterior dislocations. The mean follow-up was 6.9 years (range: 2.7-16.2 years). On final follow-up, all 21 patients were independently ambulatory with mean knee range of motion 127 degrees. No patient had symptomatic knee instability at final follow-up, despite four having isolated grade-III posterior cruciate ligament (PCL) laxity. Anatomical reduction was achieved in 19 patients, whereas 2 patients had incomplete joint reduction with a persistent grade-II fixed posterior subluxation. Scanograms revealed coronal alignment within 5 degrees of the opposite unaffected limb in 17 patients. Mean functional scores improved from preoperative 9.4 ± 4.7 (range: 2-19) to postoperative 75.9 ± 8.0 (range: 64-95) for Lysholm's and preoperative 10.7 ± 1.8 (range: 8.3-13.7) to postoperative 73.5 ± 6.7 (range: 66.7-88.7) for knee injury and osteoarthritis outcome score (KOOS) scores. Prior periarticular surgery was associated with significantly inferior Lysholm's scores (p < 0.04). Although 23.8% knees developed posttraumatic knee arthritis, no patient had undergone conversion to knee arthroplasty or arthrodesis. The study concludes that open reduction and reconstructive surgery is an effective surgical treatment for chronic irreducible knee dislocations of up to 6 months duration. An individualized, often staged approach that prioritizes joint reduction, early knee mobilization, and knee stability, ensures satisfactory clinical, radiological, and functional outcomes in the medium term. This is a clinical case series and reflects level of evidence IV.

Poster 263: Distance to Neurovascular Bundle During Iliotibial Band ACL Graft Passage: A Cadaveric Study

Objectives:For patients with significant growth remaining, the Micheli (iliotibial band) ACL reconstruction technique has proven to be a reliable procedure with minimal risk for growth disturbance. Recent cadaveric studies have demonstrated that graft passage over the top of the femur may bring the graft and surgical instrument close to the critical neurovascular structures. The purpose of this study was to evaluate the Micheli over-the-top, graft passage technique for ACL reconstruction using pediatric cadaveric knees, and measure the distance between surgical instrument tip and the peroneal nerve, tibial nerve, and popliteal artery.Methods:Gross dissection was performed on seventeen skeletally immature cadaveric knees (12 male and 5 female) between the ages of 4 and 12 years old. A 5.5” curved-tip hemostat clamp was used to create a path through the posterior capsule, after the posterior neurovascular structures were identified. The tip of the clamp was passed from an anterior medial portal through the notch postero-superiorly, towards the proximal lateral capsule, with the knee flexed to 90-100 degrees or more. Once passed, the clamp was positioned in the popliteal fossa and clinical photographs were taken from the posterior aspect of the dissected knee, visualizing the tip of the clamp and the neurovascular structures. A metric ruler was included in all photographs. Digital imaging software was used to measure the distance in centimeters from clamp tip to peroneal nerve laterally, and the popliteal artery and tibial nerve medially for all specimens, FIGURE 1. Distances were averaged and stratified to assess differences in age and sex FIGURE 2.Results:The average distances from clamp to neurovascular bundle were 0.875cm (range: 0.468-1.737cm), 0.968cm (range: 0.312-1.819cm), and 1.149cm (range: 0.202-2.409cm) for tibial nerve, popliteal artery and peroneal nerve, respectfully. Means were further calculated for age groups ≤8, 9-10, and 11-12 years old. The average distance from clamp tip to peroneal nerve was 1.400cm larger for 11–12-year-old patients vs. patients ≤8 after adjusting for sex (95% CI=[0.6, 2.2], p=0.005).Conclusions:Iliotibial band graft ACL reconstruction is one of the best options in the skeletally immature, as it has the lowest risk of growth plate complications and growth arrest. The neurovascular structures are very close to the path for over-the-top graft clamp placement with distances <1 cm in many subjects. When passing the graft through the posterior knee there may be greater accessibility on the lateral cortex of the knee among older patients who are closer in age to physeal closure. The current study provides detailed measurements of instrument proximity to the neurovascular bundle in the posterior compartment of the knee. This knowledge is important to help surgeons who perform the Micheli pediatric ACL reconstruction avoid damage to the nerves and vessels in this region. Careful instrument and graft passage, with awareness of proximity to critical structures, are important to reduce the risk of neurovascular injury.Figure 1.Measurements (cm) from clamp tip to neurovascular bundle structures in right Knee model.Figure 2.Average distance from clamp from tip to neurovascular bundle by age Error bars represent 95%CI,**p<0.01

Functional outcome of posterior cruciate ligament substituted total knee arthroplasty

Background and Aim: Total Knee Arthroplasty (TKA) is now most reliable treatment for severe arthritis. However, there is a need of a study to accurately assess and analyze the approach of a surgeon towards PCL and measure its outcome. We aimed to study clinical and functional outcome following posterior cruciate ligament substituted total knee arthroplasty.Material and Methods: Present research was carried out at Department of Orthopedics, Tertiary Care Institute of India where 50 patients were operated, 78 Total knee replacements done on 50 patients for the duration of two years. All patients were assessed clinically and functionally using the Oxford knee score. The preoperative medical evaluations of all patients were done to evaluate any potential complications that can be life-threatening or limb-threatening.Results: Most of the patients in study have excellent outcome 72% followed by good results of 14% after treatment. Out of 50 patients and 6 patient had post op suprapatellar fullness, which was relieved with medications for 3 weeks and 3 patients without no signs of immediate post-operative period, developed infection after 6 months followed which underwent staged revision total knee replacement.Conclusion: Post operatively, patients had pain free joint movements with correction of deformity. In patients with advanced osteoarthritis, gross varus deformity, fixed flexion deformity posterior cruciate ligament sacrificing total knee replacement will give greater mobility and function.