Prosthesis loosening is the leading cause of postoperative revision in unicompartmental knee arthroplasty (UKA). The deviation of medial and lateral translational installation of the prosthesis during surgery is a common clinical phenomenon and an important factor in increasing the risk of prosthesis loosening. This study established a UKA finite element model and a bone-prosthesis fixation interface micromotion prediction model. The predicted medial contact force and joint motion of the knee joint from a patient-specific lower extremity musculoskeletal multibody dynamics model of UKA were used as boundary conditions. The effects of 9 femoral component medial and lateral translational installation deviations on the Von Mises stress of the proximal tibia, the contact stress, and the micro-motion of the bone prosthesis fixation interface were quantitatively studied. It was found that compared with the neutral position (a/A of 0.492), the lateral translational deviation of the femoral component significantly increased the tibial Von Mises stress and the bone-prosthesis fixation interface contact stress. The maximum Von Mises stress and the maximum contact stress of the fixation interface increased by 14.08% and 143.15%, respectively, when a/A was 0.361. The medial translational deviation of the femoral component significantly increased the bone-prosthesis fixation interface micro-motion. The maximum value of micromotion under the conditions of femoral neutral and medial translation deviation was in the range of 20-50 μm, which is suitable for osseointegration. Therefore, based on considerations such as the micromotion range suitable for osseointegration reported in the literature, the risk of reducing prosthesis loosening, and factors that may induce pain, it is recommended that clinicians control the mounting position of the femoral component during surgery within the safe range of 0-4 mm medial translation deviation.
Humans ; Arthroplasty, Replacement, Knee/methods* ; Finite Element Analysis ; Biomechanical Phenomena ; Knee Prosthesis ; Tibia/surgery* ; Femur/surgery* ; Stress, Mechanical ; Prosthesis Failure ; Knee Joint/surgery* ; Prosthesis Design

OBJECTIVE: To explore the advantages and effectiveness of the independently developed intelligent orthopedic robot-assisted distal locking of femoral intramedullary nails. METHODS: Thirty-two adult cadaveric femur specimens were randomly divided into two groups, with 16 specimens in each group. The experimental group used the intelligent orthopedic robot to assist in the distal locking of femoral intramedullary nail holes, while the control group used the traditional method of manual locking under X-ray fluoroscopy. The locking time, fluoroscopy times, and the success rate of first locking were recorded and compared between the two groups. RESULTS: The locking time of the experimental group was (273.94±38.67) seconds, which was shorter than that of the control group [(378.38±152.72) seconds], and number of fluoroscopies was (4.56±0.81) times, which was less than that of the control group [(8.00±3.98) times]. The differences were significant [ MD=73.054 (-37.187, 85.813), P=0.049; MD=1.969 (-1.437, 2.563), P=0.002]. The first locking success rate of the experimental group was 100% (16/16), which was significantly higher than that of the control group (68.75%, 11/16) ( P=0.043). CONCLUSION The efficiency of distal locking of femoral intramedullary nails assisted by the intelligent orthopedic robot is significantly higher than that of the traditional manual locking method under fluoroscopy, as it can markedly reduce the time required for distal locking of femoral intramedullary nails, decrease intraoperative radiation exposure, and increase the success rate of locking.
Humans ; Fracture Fixation, Intramedullary/instrumentation* ; Bone Nails ; Fluoroscopy ; Femur/diagnostic imaging* ; Femoral Fractures/surgery* ; Robotic Surgical Procedures/instrumentation* ; Cadaver ; Adult ; Robotics ; Male

OBJECTIVE: To investigate the effectiveness of digital three-dimensional (3D) printing osteotomy guide plate assisted total knee arthroplasty (TKA) in treatment of knee osteoarthritis (KOA) patients with femoral internal implants. METHODS: The clinical data of 55 KOA patients who met the selection criteria between July 2021 and October 2023 were retrospectively analyzed. Among them, 26 cases combined with femoral implants were treated with digital 3D printing osteotomy guide plate assisted TKA (guide plate group), and 29 cases were treated with conventional TKA (control group). There was no significant difference in gender, age, body mass index, side, Kellgren-Lawrence classification, preoperative visual analogue scale (VAS) score, Hospital for Special Surgery (HSS) knee score, knee range of motion, and other baseline data between the two groups ( P>0.05). The operation time, intraoperative blood loss, incision length, postoperative first ambulation time, surgical complications; VAS score, knee HSS score, knee range of motion before operation, at 1 week and 3 months after operation, and at last follow-up; distal femoral lateral angle, proximal tibial medial angle, hip-knee-ankle angle and other imaging indicators at last follow-up were recorded and compared between the two groups. RESULTS: The operation time, incision length, intraoperative blood loss, and postoperative first ambulation time in the guide plate group were significantly lower than those in the control group ( P<0.05). In the control group, there were 1 case of incision rupture and bleeding and 1 case of lower limb intermuscular venous thrombosis, which was cured after symptomatic treatment. There was no complication such as neurovascular injury, incision infection, or knee prosthesis loosening in both groups. Patients in both groups were followed up 12-26 months, with an average of 16.25 months. The VAS score, HSS score, and knee range of motion improved at each time point after operation in both groups, and further improved with time after operation, the differences were significant ( P<0.05). The above indicators in the guide plate group were significantly better than those in the control group at 1 week and 3 months after operation ( P<0.05), and there was no significant difference between the two groups at last follow-up ( P>0.05). At last follow-up, the distal femoral lateral angle, the proximal tibial medial angle, and the hip-knee-ankle angle in the guide plate group were significantly better than those in the control group ( P<0.05). CONCLUSION The application of digital 3D printing osteotomy guide plate assisted TKA in the treatment of KOA patients with femoral implants can simplify the surgical procedures, overcome limitations of conventional osteotomy guides, reduce surgical trauma, achieve individualized and precise osteotomy, and effectively restore lower limb alignment and knee joint function.
Humans ; Arthroplasty, Replacement, Knee/instrumentation* ; Osteoarthritis, Knee/surgery* ; Osteotomy/instrumentation* ; Male ; Retrospective Studies ; Female ; Printing, Three-Dimensional ; Femur/surgery* ; Middle Aged ; Bone Plates ; Range of Motion, Articular ; Aged ; Treatment Outcome ; Surgery, Computer-Assisted/methods* ; Knee Prosthesis ; Knee Joint/surgery* ; Operative Time

OBJECTIVE: To evaluate precise assessment methods for predicting the optimal acetabular cup size in total hip arthroplasty (THA). METHODS: A clinical data of 73 patients (80 hips) who underwent primary THA between December 2022 and July 2024 and met the inclusion criteria was analyzed. There were 39 males and 34 females with an average age of 66.3 years (range, 56-78 years). Among them, 66 cases were unilateral THA and 7 were bilateral THAs. There were 29 patients (34 hips) of osteoarthritis, 35 patients (35 hips) of femoral neck fractures, and 9 patients (11 hips) of osteonecrosis of the femoral head. Based on anteroposterior pelvic X-ray films, three methods were employed to predict acetabular cup size, including preoperative template planning, radiographic femoral head diameter (FHD) measurement, and intraoperative FHD measurement. The predicted acetabular cup sizes from these methods were compared with the actual implanted sizes. RESULTS: The predicted acetabular cup sizes using the preoperative template planning, radiographic FHD measurement, and intraoperative FHD measurement were (51.25±2.81), (49.72±3.11), and (49.90±2.74) mm, respectively, compared to the actual implanted cup size of (50.57±2.74) mm, with no significant difference ( P>0.05). Regarding agreement with the actual implanted cup size, the preoperative template planning achieved exact matches in 35 hips (43.75%), one-size deviation in 41 hips (51.25%), and two-size deviations in 4 hips (5%); the radiographic FHD measurement achieved exact matches in 12 hips (15%), one-size deviation in 57 hips (71.25%), and two-size deviations in 11 hips (13.75%); and the intraoperative FHD measurement achieved exact matches in 26 hips (32.5%), one-size deviation in 52 hips (65%), and two-size deviations in 2 hips (2.5%). There were significant differences in agreement distributions between the three methods and the actual implanted cup sizes ( H=18.579, P<0.001). CONCLUSION The intraoperative FHD measurement, as a simple, cost-effective, and accurate method, effectively guides acetabular cup selection, reduces the risk of prosthesis wear, enhances postoperative joint stability.
Humans ; Arthroplasty, Replacement, Hip/instrumentation* ; Male ; Female ; Middle Aged ; Acetabulum/diagnostic imaging* ; Aged ; Hip Prosthesis ; Prosthesis Design ; Femur Head/surgery* ; Osteoarthritis, Hip/surgery* ; Radiography ; Femoral Neck Fractures/surgery* ; Femur Head Necrosis/surgery*

OBJECTIVE: To investigate the effectiveness of Salter osteotomy combined with subtrochanteric shortening and derotational osteotomy in treating Tönnis type Ⅲ and Ⅳ developmental dysplasia of the hip (DDH) in children and explore the urgical timing. METHODS: A retrospective collection was performed for 74 children with Tönnis type Ⅲ and Ⅳ DDH who were admitted between January 2018 and January 2020 and met the selection criteria, all of whom were treated with Salter osteotomy combined with subtrochanteric shortening and derotational osteotomy. Among them, there were 38 cases in the toddler group (age, 18-36 months) and 36 cases in the preschool group (age, 36-72 months). There was a significant difference in age between the two groups ( P<0.05), and there was no significant difference in gender, side, Tönnis typing, and preoperative acetabular index (AI) ( P>0.05). During follow-up, hip function was assessed according to the Mckay grade criteria; X-ray films were taken to observe the healing of osteotomy, measure the AI, evaluate the hip imaging morphology according to Severin classification, and assess the occurrence of osteonecrosis of the femoral head (ONFH) according to Kalamchi-MacEwen (K&M) classification criteria. RESULTS: All operations of both groups were successfully completed, and the incisions healed by first intention. All children were followed up 14-53 months, with an average of 27.9 months. There was no significant difference in the follow-up time between the two groups ( P>0.05). At last follow-up, the excellent and good rates according to the Mckay grading were 94.73% (36/38) in the toddler group and 83.33% (30/36) in the preschool group, and the difference between the two groups was significant ( P<0.05). The imaging reexamination showed that all osteotomies healed with no significant difference in the healing time between the two groups ( P>0.05). There was no significant difference in AI between the two groups at each time point after operation ( P>0.05), and the AI in the two groups showed a significant decreasing trend with time extension ( P<0.05). The result of Severin classification in the toddler group was better than that in the preschool group at last follow-up ( P<0.05). There was no significant difference in the incidence of ONFH between the two groups ( P>0.05). In the toddler group, 2 cases were K&M type Ⅰ; in the preschool group, 3 were type Ⅰ, and 1 type Ⅱ. There was no dislocation after operation. CONCLUSION Salter osteotomy combined with subtrochanteric shortening and derotational osteotomy is an effective way to treat Tönnis type Ⅲ and Ⅳ DDH in children, and surgical interventions for children aged 18-36 months can achieve better results.
Humans ; Osteotomy/methods* ; Developmental Dysplasia of the Hip/diagnostic imaging* ; Retrospective Studies ; Male ; Child, Preschool ; Female ; Infant ; Femur/surgery* ; Child ; Treatment Outcome ; Hip Dislocation, Congenital/surgery*

OBJECTIVE: To compare the effects of double-channel core decompression (CD) combined with medullary cavity irrigation with those of simple CD on progression of collapse and clinical outcomes in non-traumatic osteonecrosis of the femoral head (ONFH). METHODS: A retrospective analysis was conducted on the clinical data of 19 patients (30 hips) with non-traumatic ONFH who underwent double-channel CD combined with medullary cavity irrigation and admitted between January 2024 and October 2024 (CD+irrigation group). According to a 1: 2 ratio, 54 patients (60 hips) who underwent simple CD and were matched in terms of age, gender, and body mass index (BMI) were included as the control (CD group). There was no significant difference in baseline data such as age, gender, BMI, affected side, ONFH type, preoperative Association Research Circulation Osseous (ARCO) stage, bone marrow edema stage, visual analogue scale (VAS) score for pain, and Harris score between the two groups ( P>0.05). The postoperative discharge time and occurrence of complications were recorded for both groups. The VAS scores before operation and at discharge after operation were compared, and the differences between pre- and post-operation (change values) were calculated for intergroup comparison. The Harris scores before operation and at discharge and 3 months after operation were also compared. During follow-up, X-ray film, CT, and MRI were performed for reexamination. The ARCO stage and bone marrow edema stage were evaluated at 3 months after operation and compared with those before operation to determine whether there was radiological progression or relief. RESULTS: All incisions in both groups healed by first intention after operation, with no infection, femoral neck fracture, or other operation-related complications. All patients were followed up, and the follow-up time of the CD+irrigation group was (146.8±27.7) days, and that of the CD group was (164.3±48.2) days; there was no significant difference between the two groups ( t=1.840, P=0.069). There was no significant difference in the length of hospital stay between the two groups ( P>0.05). At discharge after operation, the VAS score of the CD+irrigation group was significantly lower than that of the CD group ( P<0.05), and the change value was significantly higher than that of the CD group ( P<0.05). The Harris scores at discharge and 3 months after operation in the CD+irrigation group were significantly higher than those in the CD group ( P<0.05). The Harris score gradually increased with time, and the differences between different time points were significant ( P<0.05). Radiological reexamination showed that there was no significant difference in the ARCO stage and the incidence of radiological progression between the two groups at 3 months after operation ( P>0.05); however, the bone marrow edema stage and the degree of bone marrow edema relief in the CD+irrigation group were better than those in the CD group, with significant differences ( P<0.05). CONCLUSION Double-channel CD combined with medullary cavity irrigation can significantly alleviate hip joint pain and improve joint function in patients with non-traumatic ONFH, reduce the degree of bone marrow edema in the femoral head, and delay the progression of ONFH.
Humans ; Femur Head Necrosis/therapy* ; Retrospective Studies ; Male ; Female ; Decompression, Surgical/methods* ; Therapeutic Irrigation/methods* ; Adult ; Treatment Outcome ; Middle Aged ; Femur Head/surgery*

OBJECTIVE: To investigate the effect of femoral condyle sliding osteotomy (FCSO) on the flexion gap and external rotation of the prosthesis in balancing coronal instability during initial total knee arthroplasty (TKA). METHODS: Between November 2021 and October 2024, FCSO technique was applied to balance the coronal medial and lateral spaces during initial TKA in 3 patients, including medial condyle sliding osteotomy (MCSO) and lateral condyle sliding osteotomy (LCSO). There were 1 male and 2 females with the age of 81, 68, and 68 years old. The affected knee has varus or valgus deformity, with tibia-femoral angles of 169.7°, 203.3°, and 162.2°, respectively. The hip-knee-ankle angle (HKA), range of motion (ROM), knee society scoring system (KSS), and pain visual analogue scale (VAS) score were used to evaluate joint function and pain relief. Based on model bone, the thickness and bone bed area of the medial and lateral femoral condyle osteotomy blocks in FCSO were measured. During TKA in 12 patients, the range of osteotomy block movement was evaluated. By simplifying the upward and forward movement of the osteotomy block into a geometric model, the impact of movement on the flexion gap and external rotation of the prosthesis was calculated. RESULTS: After application of FCSO during TKA, the limb alignment and medial and lateral balance at extension and flexion positions were restored in 3 patients. Three patients were followed up 23, 11, and 3 months, respectively. Postoperative HKA, pain VAS score, KSS score, and ROM all showed significant improvement compared to preoperative levels. The maximum thickness of osteotomy blocks by MCSO and LCSO was 17 and 12 mm, respectively. The simple upward movement of the osteotomy block mainly affected the extension gap, and had little effect on the flexion gap and external rotation of the prosthesis. Moving the osteotomy block forward at the same time had a significant impact on the flexion gap and external rotation of the prosthesis, especially on LCSO. Mild forward movement leaded to a decrease in external rotation of more than 3°, which had a serious impact on the patellar trajectory. CONCLUSION FCSO can effectively solve the problem of imbalance between the medial and lateral spaces during initial TKA, avoiding knee joint instability caused by excessive loosening and limiting the use of constrained condylar prosthesis. The distance for the downward movement of the osteotomy block in MCSO and LCSO was 3-5 mm and 6-8 mm, respectively, with 10-15 mm of space for forward movement and almost no space for backward movement. For MCSO, the upward and forward movement of the osteotomy block will increase the external rotation of the prosthesis, which is beneficial for improving the patellar trajectory and suitable for valgus knee. LCSO is suitable for varus knee, and the osteotomy block only slides vertically up and down without moving forward and backward.
Humans ; Osteotomy/methods* ; Male ; Female ; Arthroplasty, Replacement, Knee/methods* ; Aged ; Range of Motion, Articular ; Femur/surgery* ; Knee Joint/physiopathology* ; Aged, 80 and over ; Knee Prosthesis ; Treatment Outcome ; Osteoarthritis, Knee/surgery*

OBJECTIVE: To investigate whether adding 1 transverse screw (TS) to the triangular parallel cannulated screw (TPCS) fixation has a mechanical stability advantage for Pauwels type Ⅲ femoral neck fractures by conducting finite element analysis on four internal fixation methods. METHODS: Based on CT data of a healthy adult male volunteer's femur, three Pauwels type Ⅲ femoral neck fracture models (Pauwels angle 70°, Pauwels angle 80°, and Pauwels angle 70° combined with bone defect) were constructed using Mimics 21.0 software and SolidWorks 2017 software. Four different internal fixation models were built at the same time, including TPCS, TPCS+TS, three cross screws (TCS), and TPCS+medial buttress plate (MBP). The mechanical stability of different models under the same load was compared by finite element analysis. RESULTS: The femoral model established in this study exhibited a maximum stress of 28.62 MPa, with relatively higher stress concentrated in the femoral neck. These findings were comparable to previous studies, indicating that the constructed femoral finite element model was correct. The maximum stress of internal fixation in finite element analysis showed that TCS was the lowest and TPCS+MBP was the highest in Pauwels angle 70° and 80° models, while TPCS+TS was the lowest and TCS was the highest in Pauwels angle 70° combined with bone defect model. The maximum displacement of internal fixation in each fracture model was located at the top of the femoral head, with TCS having the highest maximum displacement of the femur. The maximum stress of fracture surface in finite element analysis showed that TCS was the lowest and TPCS was the highest in the Pauwels angle 70° model, while TPCS+MBP was the lowest and TPCS/TCS were the highest in the Pauwels angle 80° model and the Pauwels angle 70° combined with bone defect model, respectively. The maximum displacement of fracture surfece analysis showed that TPCS+MBP was the lowest and TCS was the highest in Pauwels angle 70° and 80° models, while TPCS+TS was the lowest and TCS was the highest in Pauwels angle 70° combined with bone defect model. CONCLUSION For Pauwels type Ⅲ femoral neck fractures, the biomechanical stability of TPCS+TS was superior to that of TPCS alone and TCS, but it has not yet reached the level of TPCS+MBP.
Finite Element Analysis ; Humans ; Femoral Neck Fractures/diagnostic imaging* ; Bone Screws ; Fracture Fixation, Internal/instrumentation* ; Male ; Bone Plates ; Stress, Mechanical ; Biomechanical Phenomena ; Tomography, X-Ray Computed ; Adult ; Femur Neck/surgery*

OBJECTIVE: To explore the corrective strategies and effectiveness of osteotomy surgery for severe lower limb deformities in hypophosphatemic rickets. METHODS: A retrospective analysis was conducted on 29 patients with severe lower limb deformities of hypophosphatemic rickets who underwent surgical treatment between February 2012 and August 2024. There were 9 males and 20 females. The age ranged from 13 to 53 years, with an average of 24.6 years. All patients were deformities of both lower limbs, presenting as 24 cases of O-shaped legs, 2 cases of wind-blown deformities, and 3 cases of X-shaped legs. Based on the full-length films of both lower limbs in the standing position before operation, the osteotomy planes of the femur, tibia, and fibula were designed. Among them, if both the same-sided thigh and leg were deformed, staged surgeries of both lower limbs were selected. If only the thigh or leg were deformed, simultaneous surgeries of both lower limbs were selected. The femur deformity was corrected immediately after osteotomy at the deformed plane; the osteotomy fragment was temporarily controlled with an external fixator, which was removed after perform internal fixation with a steel plate. After fibular osteotomy, the Ilizarov frame or Taylor frame was installed on the tibia and fibula. The threaded rods were removed and then tibial osteotomy was performed on the deformed plane. Patients using the Taylor frame did not undergo deformity correction during operation. The external fixators were adjusted starting 7 days after operation to correct the varus, valgus, and rotational deformities of the lower limb. Patients using the Ilizarov frame corrected the rotational deformity of the tibia during operation. The external fixator was adjusted starting 7 days after operation to correct the varus and valgus deformities of the lower limb. During the treatment period, the patient could walk with partial weight-bearing on the operated limb with crutches. The external fixator was removed after the bone healed. Before operation and at last follow-up, the medial proximal tibial angle (MPTA), lateral distal tibial angle (LDTA), posterior proximal tibial angle (PPTA), anterior distal tibial angle (ADTA), anatomic lateral distal femoral angle (aLDFA), posterior distal femoral angle (PDFA), and mechanical axis deviation (MAD), lower limb rotation, limb length discrepancy (LLD) were measured. The self-made scoring criteria were adopted to evaluate the degree of lower limb deformity of the patients. RESULTS: All operations were successfully completed, and no complications such as nerve or vascular injury occurred. The adjustment time of the external fixator of the lower limb after operation was 28-46 days, with an average of 37.4 days. The wearing time of the external fixator ranged from 134 to 398 days, with an average of 181.5 days. Mild pin tract infections occurred in 2 limbs. The osteofascial compartment syndrome occurred in 1 limb after operation. No complications related to orthopedic adjustment of the external fixator occurred in other patients. All patients were followed up 6-56 months, with an average of 28.2 months. At last follow-up, full-length films of both lower limbs in the standing position showed that the coronal mechanical axes of the lower limbs of all patients returned to the normal. At last follow-up, MPTA, LDTA, PPTA, aLDFA, PDFA, MAD, lower limb rotation, LLD, and the score of lower limb deformity significantly improved when compared with those before operation ( P<0.05). There was no significant difference in ADTA between pre- and post-operation ( P>0.05). The degree of lower limb deformity were rated as moderate in 2 cases and poor in 27 cases before operation and as excellent in 7 cases, good in 18 cases, and moderate in 4 cases at last follow-up, with an excellent and good rate of 86.2%. CONCLUSION For severe lower limb deformities in hypophosphatemic rickets, immediate correction of deformities with femoral osteotomy and internal plate fixation, as well as gradually correction of deformities with tibiofibular osteotomy and circular external fixation (Ilizarov frame or Taylor frame), have satisfactory therapeutic effects.
Humans ; Male ; Osteotomy/instrumentation* ; Female ; Adult ; Retrospective Studies ; Tibia/abnormalities* ; Adolescent ; Femur/abnormalities* ; Middle Aged ; Fibula/surgery* ; Rickets, Hypophosphatemic/complications* ; Young Adult ; Treatment Outcome ; External Fixators ; Bone Plates ; Lower Extremity Deformities, Congenital/etiology*

OBJECTIVE: To explore the effectiveness of artificial hemi-knee prosthesis reconstruction for bone defects after resection of pediatric osteosarcoma. METHODS: A retrospective analysis was conducted on the clinical data of 18 children with osteosarcoma who met the selection criteria and were treated between January 2016 and December 2019. There were 11 males and 7 females, aged 6-10 years (mean, 8.9 years). Osteosarcoma located in the distal femur in 11 cases and the proximal tibia in 7 cases. Among them, 12 cases were conventional osteosarcoma and 6 cases were small cell osteosarcoma, with a disease duration of 1-9 months (mean, 3.1 months). All patients received 2 cycles of preoperative chemotherapy with doxorubicin, cisplatin, and ifosfamide. After en bloc tumor segment resection, bone defects were reconstructed using custom-made artificial hemi-knee prostheses. Rehabilitation training was initiated at 8 weeks postoperatively under the protection of a knee immobilizer brace, combined with 4 cycles of adjuvant chemotherapy. During follow-up, lower limb growth length and limb shortening (compared with the healthy side) were measured, and limb function was evaluated using the Musculoskeletal Tumor Society-93 (MSTS-93) scoring system. RESULTS: All surgeries were successfully completed, with an operation time of 2.0-3.1 hours (mean, 2.4 hours) and intraoperative blood loss of 180-320 mL (mean, 230.0 mL). Incisional edge necrosis occurred in 1 case at 10 days postoperatively, while the incisions of the remaining 17 patients healed by first intention. One case developed periprosthetic infection caused by Staphylococcus aureus at 1 week postoperatively, which was cured after symptomatic treatment. All 18 patients were followed up 60-96 months (mean, 74.2 months). No local tumor recurrence was observed during follow-up. Imaging examinations showed prosthesis loosening in 2 cases, while the prosthesis of other patients were well-positioned. At last follow-up, the knee joint range of motion was 80°-120° (mean, 106.7°). The MSTS-93 score was 16-29 (mean, 24.7), with 12 cases rated as excellent, 5 good, and 1 fair. The patients' height increased by 12.8-20.0 cm (mean, 15.5 cm), the lower limb growth length was 6.0-13.0 cm (mean, 9.7 cm), and limb shortening was 1.8-4.6 cm (mean, 3.1 cm). There was no significant difference in MSTS-93 scores, lower limb growth length, or limb shortening between the distal femur group and the proximal tibia group ( P>0.05). CONCLUSION Artificial hemi-knee prosthesis reconstruction can preserve the adjacent normal epiphysis of the knee joint, maximize limb growth potential, and reduce adult limb length discrepancy, making it a suitable reconstruction option for children with knee osteosarcoma.
Humans ; Osteosarcoma/surgery* ; Male ; Child ; Female ; Knee Prosthesis ; Retrospective Studies ; Bone Neoplasms/surgery* ; Plastic Surgery Procedures/methods* ; Tibia/surgery* ; Femur/surgery* ; Arthroplasty, Replacement, Knee/methods* ; Treatment Outcome ; Chemotherapy, Adjuvant ; Femoral Neoplasms/surgery*