The surgical installation accuracy of the components in unicompartmental knee arthroplasty (UKA) is an important factor affecting the joint function and the implant life. Taking the ratio of the medial-lateral position of the femoral component relative to the tibial insert (a/A) as a parameter, and considering nine installation conditions of the femoral component, this study established the musculoskeletal multibody dynamics models of UKA to simulate the patients' walking gait, and investigated the influences of the medial-lateral installation positions of the femoral component in UKA on the contact force, joint motion and ligament force of the knee joint. The results showed that, with the increase of a/A ratio, the medial contact force of the UKA implant was decreased and the lateral contact force of the cartilage was increased; the varus rotation, external rotation and posterior translation of the knee joint were increased; and the anterior cruciate ligament force, posterior cruciate ligament force and medial collateral ligament force were decreased. The medial-lateral installation positions of the femoral component in UKA had little effect on knee flexion-extension movement and lateral collateral ligament force. When the a/A ratio was less than or equalled to 0.375, the femoral component collided with the tibia. In order to prevent the overload on the medial implant and lateral cartilage, the excessive ligament force, and the collision between the femoral component and the tibia, it is suggested that the a/A ratio should be controlled within the range of 0.427-0.688 when the femoral component is installed in UKA. This study provides a reference for the accurate installation of the femoral component in UKA.
Humans ; Arthroplasty, Replacement, Knee ; Knee Joint/surgery* ; Knee Prosthesis ; Gait ; Rotation

Objective: To investigate the clinical effects of lateral supramalleolar perforator island flaps with low rotation points in repairing foot skin and soft tissue defect wounds. Methods: The retrospective observational study was conducted. From October 2017 to August 2020, 14 patients (6 males and 8 females, aged 14-77 years) with foot skin and soft tissue defect wounds were admitted to Lanzhou University Second Hospital, including 4 cases of plantar skin tumor, 4 cases of chronic plantar ulcer, 4 cases of foot traffic injury, and 2 cases of residual wounds after deep foot burns. The wound size was 2.0 cm×2.0 cm to 7.0 cm×5.0 cm after tumor resection or debridement, which was repaired with island flap pedicled with the descending branch of the lateral supramalleolar perforator and the rotation point located at the lower front edge of the lateral ankle. The size of the flap ranged from 3.0 cm×2.0 cm to 8.0 cm×6.0 cm, and the length of vascular pedicle ranged from 8.0 to 14.0 cm. The flap was transferred by subcutaneous tunnel to repair the wound. The donor site wound of the flap was repaired with medium thickness skin graft from the lateral thigh. The survival of flaps, wound healing of the donor and recipient sites, and the occurrence of complications after operation were observed. The appearances of flaps and donor sites, and foot function were observed during follow-up. Results: The flaps of 14 patients survived successfully after operation, and the wounds in the donor and recipient sites healed well, without vascular crisis, venous congestion, or other complications. Follow-up for 2 to 24 months showed that the flaps had good appearance without bloating and were wear-resistant, the functions of wearing shoes and walking were not affected, and there was no obvious scar hyperplasia or hyperpigmentation at the donor site. Conclusions: With the descending branch of the lateral supramalleolar perforator as the pedicle and the rotation point located at the lower front edge of the lateral ankle, the island flap has a good effect in repairing the skin and soft tissue defect wound of the foot because of its reliable blood supply, simple design and operation, no need for vascular anastomosis, low rotation point, long vascular pedicle, and large radius of rotation.
Male ; Female ; Humans ; Perforator Flap/blood supply* ; Rotation ; Plastic Surgery Procedures ; Soft Tissue Injuries/surgery* ; Skin Transplantation ; Foot Injuries/surgery* ; Treatment Outcome

OBJECTIVE: To explore clinical effect of the first metatarsophalangeal joint fusion combined with lateral toe rotation Weil osteotomy in treating hallux valgus with severe metatarsal adduction. METHODS: From March 2017 to August 2021, 37 patients ( 69 feet ) with severe plantar adductor hallux valgus were treated with the first metatarsophalangeal joint fusion combined with rotational Weil osteotomy were retrospectively analyzed, including 8 males(11 feet) and 29 females (58 feet), aged from 67 to 83 years old with an average of (70.03±2.87) years old;3 cases on the left side, 2 cases on the right side and 32 cases on both sides. Visual analogue scale(VAS) was used to evaluate degree of pain relief before operation, 6 weeks after operation and at the final follow-up. American Orthopaedic Foot and Ankle Surgery (AOFAS) forefoot score was used to evaluate function of the affected foot before operation and final follow-up. Hallux valgus angle(HVA) and intermetatarsal angle(IMA) were measured before operation and at the final follow-up. RESULTS: Thirty-seven patients(69 feet) were followed up from 12 to 48 months with an average of(22.8±0.6) months. Bone healing was achieved at the first metatarsophalangeal joint from 7 to 10 weeks with an average of (8.00±1.21) weeks after operation, without delay and nonunion. HVA was increased from (44.30±2.84)° before operation to (15.20±2.13) °at the final follow-up, and had statistical difference(t=65.781, P<0.05);while no difference in IMA before and after operation(P>0.05). VAS was decreased from (6.73±1.48) points to (2.78±0.71) points at 6 months after operation(t=3.279, P<0.05), and had difference compared with the latest follow-up(1.16±1.12)(t=4.859, P<0.05). AOFAS forefoot score increased from (52.14±5.78) preoperatively to (86.70±4.86) at the fonal follow-up, and 25 feet got excellent results, 40 feet good and 4 feet fair. CONCLUSION The first metatarsophalangeal joint fusion combined with lateral toe rotation Weil osteotomy in treating severe plantar adduction hallux valgus could significantly relieve pain and appearance of forefoot, stabilize the first sequence, and significantly improve walking function.
Male ; Female ; Humans ; Aged ; Aged, 80 and over ; Metatarsal Bones/surgery* ; Hallux Valgus/surgery* ; Retrospective Studies ; Rotation ; Treatment Outcome ; Osteotomy/methods* ; Metatarsophalangeal Joint/surgery* ; Bunion ; Toes

OBJECTIVE: To explore clinical effect of rotational Scarf osteotomy in treating hallux valgus (HV) with rotation of the first metatarsal bone. METHODS: From January 2018 to October 2019, 35 patients (40 feet) with HV and rotation deformity of the first metatarsal were treated with rotational Scarf osteotomy, including 5 males and 30 females;aged from 25 to 76 years old with an average of (40.32±5.43) years old. Hallux valgus angle(HVA), intermetatarsal angle (IMA), distal metatarsal articular angle (DMAA), the first metatarsal length (FML) were observed and compared, American Orthopedic Foot and Ankle Society(AOFAS) of hallux metatarsophalangeal interphalangeal joint score and visual analogue scale (VAS) were used to evaluate functional evaluation. RESULTS: Thirty-five patients(40 feet) were followed up from 12 to 36 months with an average of (14.35±3.62) months. HVA, IMA and DMAA were corrected from (36.32±4.51) °, (14.21±3.22) ° and (28.35±4.32) ° before operation to (14.32±5.71) °, (5.83±3.97) ° and (7.32±2.14) ° after operation respectively (P<0.05). There was no satistical difference in FML before and after operation (P>0.05). AOFAS score and VAS improved from (57.00±4.31) and (6.00±1.21) before operation to (90.31±3.28) and (1.42±0.83) after operation, respectively, and had significant difference(P<0.05);according to AOFAS score, 23 feet got excellent results, 15 feet good and 2 feet fair. CONCLUSION Rotational Scarf osteotomy with strong correction and high dimension could effectively correct HV combined with rotation deformity of the first metatarsal bone, improve function of the forefoot, and obtain good clinical results.
Male ; Female ; Humans ; Adult ; Middle Aged ; Aged ; Hallux Valgus/diagnostic imaging* ; Metatarsal Bones/surgery* ; Fluorometholone ; Rotation ; Treatment Outcome ; Radiography ; Bunion ; Osteotomy/methods*

Arthroplasty, Replacement, Knee ; Humans ; Knee Joint/surgery* ; Leg ; Lower Extremity/diagnostic imaging* ; Osteoarthritis, Knee/surgery* ; Rotation ; Tibia/surgery*

OBJECTIVE: Develop an intelligent equipment that can perform multiple modes of functional exercise on the knee joint, and can accurately measure and control strength, angle, angular velocity, time, frequency and so on. METHODS: Using geared motors, magnetic powder brakes and synchronous belt wheel sets and other mechanical structure and transmission technology combined with sophisticated mechanical design methods, the knee joint multiple functional exercise methods are cleverly integrated; a highly reliable PLC is used as the control core; the resistance torque out-put by the equipment is accurately controlled by adjusting the size of the exciting current; the angle sensor is used to accurately measure the rotation angle around the axis; and the error of each parameter index and the actual measured value is controlled within 5%. RESULTS: The developed prototype has a compact structure and a simple and convenient method of use. Based on the control of joint parameters such as resistance, the expected goal is achieved. CONCLUSIONS The equipment can carry out diversified, accurate and automatic rehabilitation treatment for knee joint diseases, and has certain social and economic benefits.
Biomechanical Phenomena ; Knee Joint ; Powders ; Rotation ; Torque

OBJECTIVE: This study aimed to research whether anterior tibial crest is a reliable anatomical reference for rotational alignment of tibial component in TKA. METHODS: The study included 122 patients who underwent computed tomography angiography (CTA) examination for unilateral lower extremity trauma with normal contralateral lower extremities, including 89 males and 33 females, with an average age of(51.4±16.4) years old(ranged 18 to 81 years old). Picture archiving and communication system (PACS) was used to mark 11 lines including the surgical epicondylar axis (SEA) connecting the most prominent points of the lateral epicondyle and the deepest point of the sulcus on the medial epicondyle of the femur, axis of medial border of patellar tendon (MEPT)connecting the middle of the posterior cruciate ligament (PCL) and medial border of the patellar tendon at the level of a standard tibial cut from 8 mm distal of the lateral tibial joint surface, transverse axis of tibia (TAT) at the level of a standard tibial cut from 8 mm distal of the lateral tibial joint surface, Akagi line connecting the projected middle of the PCL and medial border of the patellar tendon at the tibial attachment, the axis of the medial 1/3 of patellar tendon(M1/3) connecting the projected middle of PCL and the medial 1/3 of the patellar tendon at the patellar tendon attachment level, Insall line connecting the projected middle of the PCL and the medial 1/3 of tibial tubercle, the axis of medial border of tibial tubercle (MBTT) connecting the projected middle of the PCL and medial border of tibial tubercle, as well as the axis of the proximal anterior tibial crest (PATC), axis 1 of the middle anterior tibial crest (MATC1), axis 2 of the middle anterior tibial crest (MATC2) and the axis of the distal anterior tibial crest (DATC) which were marked by connecting the 4 equidistant points on the sharp anterior tibial crest and the projected middle of the PCL. The angles between TAT and SEA as well as the angles between other axes and the perpendicular to SEA were measured. Pairwise differences among the 10 tibial axes were examined using One-Way ANOVA and paired RESULTS: The angles between the axes of MEPT, Akagi line, M1/3, Insall line, MBTT, PATC, MATC1, MATC2, DATC and the perpendicular to SEA were (-1.6 ±4.5)° , (1.4 ±5.0)° , (10.2±5.1)°, (11.9±5.4)°, (3.6±4.8)°, (12.0±6.9)°, (7.2±8.6)°, (7.1±10.4)°, (6.6±13.5)°, respectively. The angle between TAT and SEA was (4.1±5.3)°. MEPT was external rotation compared to SEA. M1/3, Insall line and PATC were significantly greater than Akagi line, MBTT, TAT ( CONCLUSION The middle tibial anterior crest can be used as a reference for rotational alignment of tibial component in TKA, and its reliability is better than Insall line, but worse than Akagi line, TAT and MBTT.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Arthroplasty, Replacement, Knee ; Female ; Humans ; Knee Joint/surgery* ; Male ; Middle Aged ; Posterior Cruciate Ligament/surgery* ; Reproducibility of Results ; Rotation ; Tibia/surgery* ; Young Adult

The anterior cruciate ligament (ACL) reconstruction mostly relies on the experience of surgeons. To improve the effectiveness and adaptability of the tension after ACL reconstruction in knee joint rehabilitation, this paper establishes a lateral force measurement model with relaxation characteristics and designs an on-line stiffness measurement system of ACL. In this paper, we selected 20 sheep knee joints as experimental material for the knee joint stability test before the ACL reconstruction operation, which were divided into two groups for a comparative test of single-bundle ACL reconstruction through the anterolateral approach. The first group of surgeons carried out intraoperative detection with routine procedures. The second group used ACL on-line stiffness measurement system for intraoperative detection. After that, the above two groups were tested for postoperative stability. The study results show that the tension accuracy is (- 2.3 ± 0.04)%, and the displacement error is (1.5 ± 1.8)%. The forward stability, internal rotation stability, and external rotation stability of the two groups were better than those before operation (
Animals ; Anterior Cruciate Ligament/surgery* ; Anterior Cruciate Ligament Injuries/surgery* ; Anterior Cruciate Ligament Reconstruction ; Biomechanical Phenomena ; Cadaver ; Joint Instability/surgery* ; Knee Joint/surgery* ; Range of Motion, Articular ; Rotation ; Sheep

The distal radioulnar joint is not only the main load-bearing joint in the wrist, but also the pivot of the rotation of the forearm. It is one of the most important and unique joints in the body. Maintaining the stability of the distal radioulnar joint is very important for our daily life. The tissue to stabilize the distal radioulnar joint includes bone structures and soft tissue structures. Although the contribution of soft tissue structures to its stability is far exceeding that of bone structures, the influence of abnormal bone structure on the distal radioulnar joint cannot be ignored. By reviewing the relevant literatures, this article divides the bone structural abnormalities into congenital and acquired bone structural abnormalities. The effects of congenital and acquiredbone structural abnormalities on the distal radioulnar joint stability are analysized and collated in this article, and its clinical symptoms, clinical grading, clinical treatments are also summerized. The problems of distal radioulnar joint instability in clinical practicing and its future researching directions are briefly described in order to provide some suggestions for future clinical applications.
Forearm ; Humans ; Joint Instability ; Rotation ; Ulna ; Wrist ; Wrist Joint

OBJECTIVE: To establish animal models and investigate the impact of unilateral hemilaminectomy (ULHL) and different degrees of facetectomy (FT) on the cervical spinal biomechanics. METHODS: Twenty sheep were randomly and evenly divided into 4 groups. No operation was performed for group A, right C4-C6 ULHL was performed for group B, right C4-C6 ULHL and 50% ipsilateral C4-C5 FT was performed for group C, right C4-C6 ULHL and 100% ipsilateral C4-C5 FT was performed for group D. Animals of group A, B, C and D were sacrificed 24 weeks after operating and fresh cervical spine specimens were acquired, biomechanically tested and these data were compared to determine whether ULHL and different degrees of FT led to long-term differences in range of motion. RESULTS: (1) Changes of the total range of motion of cervical spine 24 weeks after surgery: the total range of motion of group D (60.2°±8.6°) was significantly greater than group A (40.7°±6.4°) and group B (41.2°±13.1°) under flexion-extension station, the total range of motion of group D (81.5°±15.7°) was significantly greater than that of group A (56.7°±12.2°) and group B (57.7°±12.8°) under lateral bending station, and the total range of motion of group D (38.5°±17.5°) had no obvious increase compared with group A (26.4°±9.9°) and group B (27.1°±10.9°) under axial rotation station. The total range of motion of group C had no obvious increase compared with group A and group B under flexion-extension station (44.1°±11.7°), lateral bending station (73.6°±11.4°) and axial rotation station (31.3°±11.5°). (2) Changes of the intersegmental motion 24 weeks after surgery: the intersegmental motion of group D (20.3°±4.6°) at C4-C5 was significantly greater than that of group A (11.7°±3.4°) and group B (11.9°±2.1°) under flexion-extension station, the intersegmental motion of group D (26.8°±3.5°) at C4-C5 was significantly greater than that of group A (15.2°±3.1°) and group B (16.2°±3.2°) under lateral bending station, the intersegmental motion of group D (15.2°±3.5°) at C4-C5 was significantly greater than that of group A (6.6°±2.3°) and group B (7.1°±1.9°) under axial rotation station. The intersegmental motion of group C (21.2°±4.1°) at C4-C5 was significantly greater than that of group A and group B under lateral bending station, the intersegmental motion of group C at C4-C5 had no obvious increase compared with group A and group B under flexion-extension station (15.7°±3.7°) and axial rotation station (10.3°±3.1°). CONCLUSION ULHL does not affect cervical stability, ULHL and 50% ipsilateral FT does not affect the long-term cervical stability, ULHL and 100% ipsilateral FT can lead to long-term instability under lateral bending and flexion-extension station.
Animals ; Biomechanical Phenomena ; Cervical Vertebrae ; Laminectomy ; Range of Motion, Articular ; Rotation ; Sheep