OBJECTIVE: To explore application value and effectiveness of virtual reality technology combined with isokinetic muscle strength training in the rehabilitation of patients after anterior cruciate ligament (ACL) reconstruction surgery. METHODS: Forty patients who underwent ACL reconstruction surgery from December 2021 to January 2023 were selected and divided into control group and observation group according to treatment methods, 20 patients in each group. Control group was received routine rehabilitation training combined with isokinetic muscle strength training, including 15 males and 5 females, aged from 17 to 44 years old, with an average of (29.10±8.60) years old. Observation group was performed virtual reality technology combined with isokinetic muscle strength training, including 16 males and 4 females, aged from 17 to 45 years old with an average of (30.95±9.11) years old. Lysholm knee joint score, knee extension peak torque, and knee flexion peak torque between two groups at 12 (before training) and 16 weeks (after training) after surgery were compared. RESULTS: All patients were followed up for 1 to 6 months with an average of (3.30±1.42) months. There were no statistically significant difference in Lysholm knee joint score, peak knee extension peak torque, and peak knee flexion peak torque between two groups (P>0.05) before training. After training, Lysholm knee joint score, knee extension peak torque, and knee flexion peak torque of both groups were improved compared to before training (P<0.05);there were significant difference in Lysholm knee joint score, knee extension peak torque, and knee flexion peak torque between two groups(P<0.05). CONCLUSION The application of virtual reality technology combined with isokinetic muscle strength training could promote recovery of knee joint function and enhance muscle strength in patients after ACL reconstruction surgery in further.
Male ; Female ; Humans ; Adolescent ; Young Adult ; Adult ; Middle Aged ; Anterior Cruciate Ligament Injuries/surgery* ; Resistance Training ; Knee Joint/surgery* ; Anterior Cruciate Ligament Reconstruction/methods* ; Knee Injuries/surgery* ; Muscle Strength/physiology*

Posterior-stabilized total knee prostheses have been widely used in orthopedic clinical treatment of knee osteoarthritis, but the patients and surgeons are still troubled by the complications, for example severe wear and fracture of the post, as well as prosthetic loosening. Understanding the in vivo biomechanics of knee prostheses will aid in the decrease of postoperative prosthetic revision and patient dissatisfaction. Therefore, six different designs of posterior-stabilized total knee prostheses were used to establish the musculoskeletal multibody dynamics models of total knee arthroplasty respectively, and the biomechanical differences of six posterior-stabilized total knee prostheses were investigated under three simulated physiological activities: walking, right turn and squatting. The results showed that the post contact forces of PFC Sigma and Scorpio NGR prostheses were larger during walking, turning right, and squatting, which may increase the risk of the fracture and wear as well as the early loosening. The post design of Gemini SL prosthesis was more conductive to the knee internal-external rotation and avoided the edge contact and wear. The lower conformity design in sagittal plane and the later post-cam engagement resulted in the larger anterior-posterior translation. This study provides a theoretical support for guiding surgeon selection, improving posterior-stabilized prosthetic design and reducing the prosthetic failure.
Arthroplasty, Replacement, Knee/methods* ; Biomechanical Phenomena ; Humans ; Knee Joint/surgery* ; Knee Prosthesis ; Prosthesis Design ; Range of Motion, Articular/physiology* ; Tibia/surgery*

BACKGROUNDThe application of second-generation constrained condylar knee (CCK) prostheses has not been widely studied. This retrospective study was carried out to evaluate the clinical and radiographic outcomes of a second-generation CCK prosthesis for complex primary or revision total knee arthroplasty (TKA).

METHODSIn total, 51 consecutive TKAs (47 patients) were performed between June 2003 and June 2013 using second-generation modular CCK prostheses. The follow-up was conducted at 3rd day, 1st, 6th, and 12th months postoperatively and later annually. Anteroposterior (AP), lateral, skyline, and long-standing AP radiographs of the affected knees were taken. The Hospital for Special Surgery (HSS) Knee Score, the Knee Society Knee Score (KSKS), the Knee Society Function Score (KSFS), and range of motion (ROM) were also recorded. Heteroscedastic two-tailed Student's t-tests were used to compare the HSS score and the Knee Society score between primary and revision TKAs. A value of P < 0.05 was considered statistically significant.

RESULTSFour knees (two patients) were lost to follow-up, and 47 knees (31 primary TKAs and 16 revision TKAs) had a mean follow-up time of 5.5 years. The mean HSS score improved from 51.1 ± 15.0 preoperatively to 85.3 ± 8.4 points at the final follow-up (P < 0.05). Similar results were observed in terms of the KSKS and KSFS, which improved from 26.0 ± 13.0 to 80.0 ± 12.2 and from 40.0 ± 15.0 to 85.0 ± 9.3 points, respectively (P < 0.05). No significant difference in the HSS, KSKS, KSFS, or ROM was found between primary and revision TKAs (P > 0.05). Two complications were observed in the revision TKA group (one intraoperative distal femur fracture and one recurrence of infection) while one complication (infection) was observed in the primary TKA group. No prosthesis loosening, joint dislocation, patella problems, tibial fracture, or nerve injury were observed. Radiolucent lines were observed in 4% of the knees without progressive osteolysis.

CONCLUSIONSSecond-generation modular CCK prostheses are a safe and practical treatment for both primary and revision knees that cannot be balanced. However, further studies focusing on different types of constrained prostheses are required to validate these results.

Adult ; Aged ; Aged, 80 and over ; Arthroplasty, Replacement, Knee ; Female ; Follow-Up Studies ; Humans ; Knee Joint ; physiology ; surgery ; Knee Prosthesis ; Male ; Middle Aged ; Prosthesis Failure ; Range of Motion, Articular ; physiology ; Retrospective Studies

Knee osteoarthritis (KOA) is the most common knee joint disease. Although KOA belongs to a disease of degeneration of knee joint cartilage, its pathology involves cartilage, subchondral bone, meniscus, synovial membrane, articular capsule and other joint tissue. The infrapatellar fat pad (IPFP), an intracapsular but extrasynovial structure, has some special characteristics of endocrine metabolism, then it has double roles in the development of KOA, but its protective effect is much more than harmful effect. Considering protective roles of IPFP in KOA and some serious complications after IPFP resection, the surgeon shall protect IPFP as far as possible if total knee arthroplasty surgical field is good. If it is necessary to improve the surgical field, its fibrotic tissue even all part can be removed.
Adipose Tissue ; physiology ; Arthroplasty, Replacement, Knee ; Humans ; Knee Joint ; physiopathology ; surgery ; Osteoarthritis, Knee ; surgery

PURPOSE: This study investigated the correlation between isometric muscle strength, gross motor function, and gait parameters in patients with spastic cerebral palsy and to find which muscle groups play an important role for gait pattern in a flexed knee gait. MATERIALS AND METHODS: Twenty-four ambulatory patients (mean age, 10.0 years) with spastic cerebral palsy who were scheduled for single event multilevel surgery, including distal hamstring lengthening, were included. Preoperatively, peak isometric muscle strength was measured for the hip flexor, hip extensor, knee flexor, and knee extensor muscle groups using a handheld dynamometer, and three-dimensional (3D) gait analysis and gross motor function measure (GMFM) scoring were also performed. Correlations between peak isometric strength and GMFM, gait kinematics, and gait kinetics were analyzed. RESULTS: Peak isometric muscle strength of all muscle groups was not related to the GMFM score and the gross motor function classification system level. Peak isometric strength of the hip extensor and knee extensor was significantly correlated with the mean pelvic tilt (r=-0.588, p=0.003 and r=-0.436, p=0.033) and maximum pelvic obliquity (r=-0.450, p=0.031 and r=-0.419, p=0.041). There were significant correlations between peak isometric strength of the knee extensor and peak knee extensor moment in early stance (r=0.467, p=0.021) and in terminal stance (r=0.416, p=0.043). CONCLUSION: There is no correlation between muscle strength and gross motor function. However, this study showed that muscle strength, especially of the extensor muscle group of the hip and knee joints, might play a critical role in gait by stabilizing pelvic motion and decreasing energy consumption in a flexed knee gait.
Biomechanical Phenomena ; Cerebral Palsy/*physiopathology/surgery ; Female ; Gait/*physiology ; Humans ; Isometric Contraction/physiology ; Knee/physiopathology ; Knee Joint/surgery ; Male ; Muscle Spasticity/etiology/physiopathology ; Muscle Strength/*physiology ; Muscle Strength Dynamometer ; Muscle, Skeletal/*physiopathology ; Pelvis ; Postural Balance/physiology ; Tenotomy

OBJECTIVETo study mechanical affect of knee joint of reasonable positioning of femoral tunnel during knee posterior cruciate ligament (PCL) double-bundle reconstruction and graft fixation after reconstruction by virtual reality interactive technology and evaluate the biomechanical response of knee after reconstruction by finite element analysis.

METHODSKnee specimens from five fresh frozen cadavers were used. Computer simulations and biomechanical experiments were used in this study. Experiments on flexion and extension movements of the knee joint were performed on specimens of fresh human knee joint. Laser three dimensional scanning was used to record and calculate the indexes of movements. Three-dimensional models of knee joint bone structure were then reconstructed on computer with the experimental data. Simulations of flexion and extension movements were carried out on the models to show the spatial positions of femur and tibia and label the attachment sites of PCL. Ten test points in the anterior,posterior, proximal, distal at the femoral attachment area of anterior and lateral bundle (ALB) and postoperior medial bundle (PMB) were selected and the central points of tibial en attachment areat anchored. The distance btween each two points of two article surface was calculated and contacted by software of Geomagic. Model was import software Ansys, adopting the tetrahedron unit a finite element model of complex tibial and femoral was set up to simulat human walking in one leg,on this condition the the joint surface force of model under weight impact load were analyzed.

RESULTSThe three-dimensional models could demonstrate the spatial positions of the bone structure of the knee in different flexions and extensions. The models could be used to measure the spatial distance between 2 points on the femoral and tibial planes by software Geomagic. There was significantly difference among the length changes of anterolateral bundle and posteromedial bundle at every fixed point with different flexion angles (P<0.05), so the fixed angle with different points. The length changes of anterior lateral bundle's A2, A1 and posterior medial bundle's B3, B1 points were (1.35±0.19) mm, (5.41±1.22) mm, (1.95±0.04) mm and (5.23±2.21) mm, respectively. The A2 and B3 points' length changes were the less, and that of the Al and B1 points were the more. It had no significant difference between the length changes of anterior lanteral bundle's A2 and A3 point (P=0.913>0.05). All of the maximal length changes of anterior lateral bundle's A2, A3 and postterior medial bundle's B3 points were less than 2 mm.

CONCLUSIONThe models of knee joint were builded through computer technology and it can be measure the lenth of cruciate ligament with software Geomagic exactly. The femoral tunnel for the PCL double-bundle reconstruction should be located as follows: ALB at the middle point of upper edge of femoral attachment site (proximal point),while PMB at the middle point of femoral attachment site (proximal point). This model provides a satisfactory method for the evaluation of the biomechanical response of knee after cruciate ligament reconstruction.

Adult ; Aged ; Biomechanical Phenomena ; Computer-Aided Design ; Female ; Femur ; surgery ; Humans ; Knee Joint ; physiology ; Male ; Middle Aged ; Posterior Cruciate Ligament ; surgery ; Reconstructive Surgical Procedures ; methods

BACKGROUND: Anatomic footprint restoration of anterior cruciate ligament (ACL) is recommended during reconstruction surgery. The purpose of this study was to compare and analyze the femoral and tibial tunnel positions of transtibial single bundle (SB) and transportal double bundle (DB) ACL reconstruction using three-dimensional computed tomography (3D-CT). METHODS: In this study, 26 patients who underwent transtibial SB ACL reconstruction and 27 patients with transportal DB ACL reconstruction using hamstring autograft. 3D-CTs were taken within 1 week after the operation. The obtained digital images were then imported into the commercial package Geomagic Studio v10.0. The femoral tunnel positions were evaluated using the quadrant method. The mean, standard deviation, standard error, minimum, maximum, and 95% confidence interval values were determined for each measurement. RESULTS: The femoral tunnel for the SB technique was located 35.07% +/- 5.33% in depth and 16.62% +/- 4.99% in height. The anteromedial (AM) and posterolateral (PL) tunnel of DB technique was located 30.48% +/- 5.02% in depth, 17.12% +/- 5.84% in height and 34.76% +/- 5.87% in depth, 45.55% +/- 6.88% in height, respectively. The tibial tunnel with the SB technique was located 45.43% +/- 4.81% from the anterior margin and 47.62% +/- 2.51% from the medial tibial articular margin. The AM and PL tunnel of the DB technique was located 33.76% +/- 7.83% from the anterior margin, 45.56% +/- 2.71% from the medial tibial articular margin and 53.19% +/- 3.74% from the anterior margin, 46.00% +/- 2.48% from the medial tibial articular margin, respectively. The tibial tunnel position with the transtibial SB technique was located between the AM and PL tunnel positions formed with the transportal DB technique. CONCLUSIONS: Using the 3D-CT measuring method, the location of the tibia tunnel was between the AM and PL footprints, but the center of the femoral tunnel was at more shallow position from the AM bundle footprint when ACL reconstruction was performed by the transtibial SB technique.
Adult ; Anterior Cruciate Ligament Reconstruction/*methods ; *Femur/radiography/surgery ; Humans ; Imaging, Three-Dimensional/*methods ; Knee Joint/physiology ; Male ; Prospective Studies ; Surgery, Computer-Assisted/*methods ; *Tibia/radiography/surgery ; Tomography, X-Ray Computed

A goal of total knee arthroplasty is to obtain symmetric and balanced flexion and extension gaps. Controversy exists regarding the best surgical technique to utilize to obtain gap balance. Some favor the use of a measured resection technique in which bone landmarks, such as the transepicondylar, the anterior-posterior, or the posterior condylar axes are used to determine proper femoral component rotation and subsequent gap balance. Others favor a gap balancing technique in which the femoral component is positioned parallel to the resected proximal tibia with each collateral ligament equally tensioned to obtain a rectangular flexion gap. Two scientific studies have been performed comparing the two surgical techniques. The first utilized computer navigation and demonstrated a balanced and rectangular flexion gap was obtained much more frequently with use of a gap balanced technique. The second utilized in vivo video fluoroscopy and demonstrated a much high incidence of femoral condylar lift-off (instability) when a measured resection technique was used. In summary, the authors believe gap balancing techniques provide superior gap balance and function following total knee arthroplasty.
Arthroplasty, Replacement, Knee/adverse effects/*methods ; Fluoroscopy/methods ; Humans ; Knee Joint/physiology/surgery ; Surgery, Computer-Assisted/methods ; Treatment Outcome

BACKGROUNDTotal knee arthroplasty (TKA) is a successful and frequently performed procedure in orthopedic surgery. The diagnosis of peri-prosthetic joint infection following TKA remains challenging. The present study estimated the usefulness of knee skin temperature (measured by infrared thermography) and serum soluble intercellular adhesion molecule-1 (sICAM-1) in the diagnosis of post-operative knee peri-prosthetic infection.

METHODSPatients were divided into three groups: 21 patients undergoing uncomplicated TKAs, seven with prosthesis infection, and three undergoing TKA revisions. The serum levels of interleukin-6 (IL-6), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and sICAM-1 as well as the local knee skin temperature were measured pre-operatively and on Days 1 and 7 and at 1, 3, and 6 months post-operatively in Groups 1 and 3. The same parameters were measured in Group 2 at the time of prosthesis infection diagnosis.

RESULTSIn Group 1, the levels of IL-6, CRP, ESR, and knee skin temperature were significantly elevated post-operatively, but returned to baseline levels within 6 months. The sICAM-1 levels were not significantly different. The mean differential temperature (MDT) and levels of siCAM-1, IL-6, CRP, and ESR differed significantly between Groups 1 and 2. The MDT had returned to normal in Group 3 by 6 months post-operatively.

CONCLUSIONSElevations in IL-6, CRP, ESR, and MDT in patients undergoing TKA could be a normal response to surgical trauma, but sustained elevations may be indicative of complications. The knee skin temperature and sICAM-1 may be used as indicators in the diagnosis of knee prosthesis infection following TKA.

Adult ; Aged ; Arthroplasty, Replacement, Knee ; adverse effects ; Blood Sedimentation ; C-Reactive Protein ; metabolism ; Female ; Humans ; Intercellular Adhesion Molecule-1 ; metabolism ; Interleukin-6 ; blood ; Knee Joint ; immunology ; surgery ; Male ; Middle Aged ; Prospective Studies ; Skin Temperature ; physiology ; Thermography ; methods

The capacity to perform certain activities is frequently compromised after total knee arthroplasty (TKA) due to a functional decline resulting from decreased range of motion and a diminished ability to kneel. In this manuscript, the current biomechanical understanding of hyperflexion and kneeling before and after TKA will be discussed. Patellofemoral and tibiofemoral joint contact area, contact pressure, and kinematics were evaluated in cadaveric studies using a Tekscan pressure measuring system and Microscribe. Testing was performed on intact knees and following cruciate retaining and posterior stabilized TKA at knee flexion angles of 90degrees, 105degrees, 120degrees, and 135degrees. Three loading conditions were used to simulate squatting, double stance kneeling, and single stance kneeling. Following TKA with double stance kneeling, patellofemoral contact areas did not increase significantly at high knee flexion angle (135degrees). Kneeling resulted in tibial posterior translation and external rotation at all flexion angles. Moving from double to single stance kneeling tended to increase pressures in the cruciate retaining group, but decreased pressures in the posterior stabilized group. The cruciate retaining group had significantly larger contact areas than the posterior stabilized group, although no significant differences in pressures were observed comparing the two TKA designs (p < 0.05). If greater than 120degrees of postoperative knee range of motion can be achieved following TKA, then kneeling may be performed with less risk in the patellofemoral joint than was previously believed to be the case. However, kneeling may increase the likelihood of damage to cartilage and menisci in intact knees and after TKA increases in tibiofemoral contact area and pressures may lead to polyethyelene wear if performed on a chronic, repetitive basis.
*Arthroplasty, Replacement, Knee ; Biomechanical Phenomena ; Cadaver ; Humans ; Knee Joint/*physiopathology/surgery ; Osteoarthritis, Knee/*physiopathology/surgery ; Patellofemoral Joint/physiopathology/surgery ; Posture/physiology ; Range of Motion, Articular