Objective:To investigate the mid-and long-term clinical efficacy of modified Colonna arthroplasty in the treatment of unilateral dislocation type developmental dysplasia of hip (DDH) in adolescents.Methods:A total of 28 adolescent DDH patients with unilateral dislocation who underwent modified Colonna capsular arthroplasty from January 2016 to January 2018 in the 920th Hospital of Joint Logistics Support Force of People's Liberation Army were retrospectively analyzed. There were 4 males and 24 females, aged 16.5±5.0 years (range, 10-25 years). The mean body mass index was 21.2±1.1 kg/m 2 (range, 18.7-24.1 kg/m 2). According to DDH classification, 10 cases were Tonnis type III and 18 cases were Tonnis type IV. The postoperative lateral center-edge angle, acetabular coverage, femoral anteversion angle and leg length discrepancy were measured. The operation time, intraoperative blood loss, visual analogue scale (VAS) of hip pain, Harris hip score (HHS) and congenital dislocation of the hip score were recorded. Results:All patients successfully completed the operation and were followed up for 72.1±5.2 months (range, 60-84 months). The operation time was 81.6±4.3 min (range, 70-90 min), the intraoperative blood loss was 177.5±12.6 ml (range, 160-200 ml), and the hospital stay was 6.8±0.7 days (range, 6-9 days). The VAS score of the hip joint was 1.8±0.6 before operation and 2.3±0.6 at the last follow-up, and the difference was not statistically significant ( t=2.845, P=0.224). The preoperative HHS score was 57.1±5.9, and it increased to 87.3±4.0 at the last follow-up, and the difference was statistically significant ( t=-22.141, P=0.001). At the last follow-up, the femoral anteversion angle was 17.0°±1.5°, which was lower than that before operation 41.6°±2.4°, with a statistically significant difference ( t=-44.868, P=0.008). The leg length discrepancy was 10.2±2.3 mm, which was lower than that before operation (26.4±6.1 mm), with a statistically significant difference ( t=-12.892, P<0.001). The lateral center-edge angle was 28° (26°, 30°), and the acetabular coverage rate was 78% (76%, 79%). The curative effect evaluation standard score of congenital dislocation of the hip was 24 (16.7, 25.7) points, including 7 excellent cases, 14 good cases, 4 fair cases, and 3 poor cases. The excellent and good rate was 75% (21/28). Conclusion:The modified Colonna arthroplasty for the treatment of unilateral dislocation DDH in adolescents has good mid-and long-term hip function recovery and radiographic improvement.

Objective:To investigate the stability and feasibility of using absorbable screws during Bernese periacetabular osteotomy.Methods:A retrospective analysis was conducted on a 36 year-old woman diagnosed with developmental dysplasia of the hip, who had undergone Bernese periacetabular osteotomy. Finite element analysis was used to simulate the stability of the acetabulum under loads of 10%, 20%, 50%, and 100% of the patient's weight. The structural stiffness of the pelvis and the maximum equivalent stress on the absorbable screws were observed under different conditions, including whether the acetabular bone block and the ilium were in contact, whether 3 or 4 screws were used, and whether a graft (including fibular cortical bone and PEEK grafts) was used.Results:The structural stiffness of the pelvis fixed with four screws increased by 67%-94% compared to that with three screws. After using a graft, the structural stiffness of the pelvis increased by 50%-83%. As the load increased, the maximum equivalent stress on the screws also increased. When the acetabular bone block and the ilium had no contact, no graft was used, and only three screws were used for fixation, the maximum equivalent stress could reach 518.9 MPa, while this value dropped to 61% when four screws were used (318.7 MPa). When the acetabular bone block and the ilium were in contact, the maximum equivalent stress was about 12% of that when there was no contact, regardless of the number of screws used. When a cortical bone graft or a PEEK graft was used, the maximum equivalent stress could drop to 21%-26% of that without a graft. When the screw strength was 130 MPa, a load of 20% of body weight was applied, and only three screws were used without a graft, the equivalent stress could exceed the strength of the screw; if four screws were used, the equivalent stress was slightly higher than the strength of the screw when a load of 50% of body weight was applied. However, when a graft was used (either cortical bone or PEEK), even when a load of 100% of body weight was applied, the equivalent stress was slightly lower than the strength of the screw.Conclusion:Absorbable screws can provide sufficient stability for Bernese periacetabular osteotomy. The contact between the acetabular bone block and the ilium, an increase in the number of screws, and the use of grafts (cortical bone and PEEK grafts) can further improve stability. Therefore, absorbable screws have broad application prospects in Bernese periacetabular osteotomy.

Objective:To investigate the outcomes of periacetabular osteotomy (PAO) through modified Smith-Petersen or Bikini approach with an auxiliary posterolateral incision for developmental dysplasia of hip (DDH).Methods:85 patients (97 hips) who underwent PAO through modified Smith-Petersen or Bikini approach with auxiliary posterolateral incision for DDH in the 920th Hospital of Joint Logistics Support Force of Chinese People's Liberation Army or the Second Xiangya Hospital of Central South University from January 2016 to January 2021 were retrospectively analyzed. There were 70 females and 15 males, with an average age of 28.6±8.4 years (12-49). According to the Hartofilakidis classification, all patients were classified as type Ⅰ. There were 77 hips classified as Grade 0 and 20 hips classified as Grade 1 according to the T?nnis classification. The X-ray evaluation including the lateral central edge angle (LCEA), t?nnis angle (TNS) and anterior central edge angle (ACEA), visual analogue score (VAS) and modified Harries hip score (mHHS) were recorded preoperatively and during each postoperative follow-up. The cumulative sum (CUSUM) method was used to fit the learning curves of operation time.Results:All patients were followed-up with an average of 52.7±18.9 months (21 to 84). The average operative time and intraoperative blood loss were 95.9±28.2 min (65 to 215) and 414.7±97.0 ml (250 to 900), respectively. The learning curve of operation time was 10 cases. The average LCEA 32.39° (30.29°, 34.92°), TNS 3.14° (1.56°, 5.67°) and ACEA 31.55° (29.07°, 33.88°) were all significantly improved compared to preoperative values ( Z=-30.764, P<0.001; Z=30.595, P<0.001; Z=-38.134, P<0.001). The average VAS was reduced from 5.18±0.88 points preoperatively to 1.27±0.93 points postoperatively with significant difference ( t=51.231, P<0.001). The average mHHS was increased from 73.12±9.17 to 92.02±4.05 postoperatively with significant difference ( t=-26.902, P<0.001). No patients received total hip arthroplasty during the follow-up period. Conclusion:Bernese PAO through modified Smith-Petersen or Bikini approach with a small auxiliary posterolateral incision was not only a safe and effective method for the treatment of DDH but also shortened the learning curve and reduced difficulty of the surgery.

Objective:To investigate the short-term efficacy of rotational femoral neck osteotomy with preservation of the round ligament in the treatment of subchondral insufficiency fracture of the femoral head (SIFFH) in young and middle-aged people.Methods:A retrospective case series study was used to analyze the clinical data of 13 patients with SIFFH, who were admitted to 920th Hospital of Joint Logistics Support Force from January 2017 to January 2022. The patients included 10 males and 3 females, aged 22-49 years [(33.5±8.3)years]. There were 6 patients with fracture on the left hip and 7 on the right hip. All the patients were treated by rotational femoral neck osteotomy with preservation of the round ligament. Postoperatively, standardized joint functional training was given. The operative time and intraoperative bleeding were recorded. The modified Harris hip score and visual analogue score (VAS) were compared preoperatively, at 3, 6 months postoperatively and at the final follow-up. Radiological examinations were used to observe the occurrence of any collapse of the femoral head, non-union at osteotomy site or other complications.Results:The patients were followed up for 13-24 months [(17.9±3.1)months]. The operative time was (127.3±9.8)minutes, with the intraoperative bleeding of (393.9±21.9)ml. The values of modified Harris hip score were (61.6±3.3)points, (80.2±4.4)points, and (91.9±4.1)points at 3, 6 months postoperatively and at the final follow-up, respectively, being significantly higher than the preoperative (51.4±3.5)points (all P<0.05), and there were significant differences between different postoperative timepoints (all P<0.05). The values of VAS were (4.9±1.1)points, (3.0±0.9)points, and (1.4±0.5)points at 3, 6 months postoperatively and at the final follow-up, respectively, being significantly lower than preoperative (6.7±0.9)points (all P<0.05), and there were significant differences between different postoperative timepoints (all P<0.05). Imaging examination showed no femoral head collapse, with all the bones healed at the osteotomy site. There were no serious complications such as bone non-union, incision infection or peripheral nerve injury. Conclusion:Rotational femoral neck osteotomy with preservation of the round ligament in treating SIFFH in the young and middle-aged population has the advantages of shortened operative time, less intraoperative bleeding, promoted hip function recovery, attenuated pain and decreased complications, showing a satisfactory early effect.

Objective:To investigate the efficacy and safety of modified Bikini approach periacetabular osteotomy in the treatment of developmental hip dysplasia under 50 years of age.Methods:The clinical data of 39 patients with developmental hip dysplasia who underwent periacetabular osteotomy in the Department of Orthopedics, Guizhou Provincial People′s Hospital from June 2016 to June 2021 were retrospectively analyzed.Among them, 20 patients (21 hips) underwent the improved Bikini approach (study group) and 19 patients (20 hips) underwent the improved Smith-Petersen approach (control group).In the study group, there were 3 males and 17 females, aged( M(IQR))27.5 (14.3) years (range:11 to 44 years).In the control group, there were 2 males and 17 females, aged 27.5 (19.3) years (range:17 to 47 years).Both groups were sutured in the same manner by the same physician.Incision length, operation time, intraoperative blood loss and complications were recorded.X-ray images, anterior central marginal angle (ACE), lateral central marginal Angle (LCE) and acetabulum tilt angle (Tonnis AI) were measured before and after the operation.The coverage rate of acetabulum to femoral head (AHI) was measured and calculated, and the healing time was observed.Harris Hip score, International Hip score (IHOT)-12 and visual analogue scale (VAS) were recorded before and after surgery.Vancouver Scar Scale (VSS) score and patient and observer scar assessment scale (POSAS) score were recorded 12 months after surgery.The independent sample t test,Wilcoxon rank sum test, χ2 test or Fisher exact test was used to compare the clinical efficacy between the two groups, respectively. Results:All patients successfully completed the operation.There was no significant difference in operation time and intraoperative blood loss between the two groups (all P>0.05).The incision length of the study group was smaller than that of the control group, and the difference was statistically significant (10.5(5.0)cm vs.15.0(3.0), W=309.000, P=0.007).Patients were followed up for (19.1±11.1) months (range:12 to 60 months).Femoral nerve stretching injury occurred in 2 cases and sciatic branch fracture occurred in 1 case in the study group, all of which recovered to normal at 3 months follow-up, while no corresponding injury occurred in the control group.Lateral femoral cutaneous nerve injury occurred in 3 cases in the study group and 2 cases in the control group.Delayed wound healing occurred in 1 case in each of the two groups, and both healed after re-operation debridement and suture.Pubic branch nonunion occurred in 4 patients in the study group and 5 patients in the control group.There were no serious complications such as sciatic nerve and femoral blood vessel injury between the 2 groups, and there was no statistical significance in the incidence of complications between the 2 groups (52.4%(11/21) vs.40.0%(8/20), χ2=0.631, P=0.427).The clinical healing time of the patient was (4.5±1.3) months after surgery (range:3.0 to 8.0 months).There were no significant differences in ACE, LCE, Tonnis AI and AHI between the 2 groups (all P>0.05).At the last follow-up, there were no significant differences in VAS,Harris hip score and IHOT-12 score between the two groups (all P>0.05).The incision scars in the study group were smaller than those in the control group, and the differences in VSS and POSAS were statistically significant (all P<0.05). Conclusion:Compared with the improved Smith-Petersen approach, the improved Bikini approach has the same early clinical efficacy in the treatment of patients with developmental hip dysplasia under the age of 50, and has the advantages of smaller postoperative incision scars, more hidden and beautiful incision, and no serious complications, which is worthy of further study and promotion.

Objective:To investigate the efficacy and safety of modified Bikini approach periacetabular osteotomy in the treatment of developmental hip dysplasia under 50 years of age.Methods:The clinical data of 39 patients with developmental hip dysplasia who underwent periacetabular osteotomy in the Department of Orthopedics, Guizhou Provincial People′s Hospital from June 2016 to June 2021 were retrospectively analyzed.Among them, 20 patients (21 hips) underwent the improved Bikini approach (study group) and 19 patients (20 hips) underwent the improved Smith-Petersen approach (control group).In the study group, there were 3 males and 17 females, aged( M(IQR))27.5 (14.3) years (range:11 to 44 years).In the control group, there were 2 males and 17 females, aged 27.5 (19.3) years (range:17 to 47 years).Both groups were sutured in the same manner by the same physician.Incision length, operation time, intraoperative blood loss and complications were recorded.X-ray images, anterior central marginal angle (ACE), lateral central marginal Angle (LCE) and acetabulum tilt angle (Tonnis AI) were measured before and after the operation.The coverage rate of acetabulum to femoral head (AHI) was measured and calculated, and the healing time was observed.Harris Hip score, International Hip score (IHOT)-12 and visual analogue scale (VAS) were recorded before and after surgery.Vancouver Scar Scale (VSS) score and patient and observer scar assessment scale (POSAS) score were recorded 12 months after surgery.The independent sample t test,Wilcoxon rank sum test, χ2 test or Fisher exact test was used to compare the clinical efficacy between the two groups, respectively. Results:All patients successfully completed the operation.There was no significant difference in operation time and intraoperative blood loss between the two groups (all P>0.05).The incision length of the study group was smaller than that of the control group, and the difference was statistically significant (10.5(5.0)cm vs.15.0(3.0), W=309.000, P=0.007).Patients were followed up for (19.1±11.1) months (range:12 to 60 months).Femoral nerve stretching injury occurred in 2 cases and sciatic branch fracture occurred in 1 case in the study group, all of which recovered to normal at 3 months follow-up, while no corresponding injury occurred in the control group.Lateral femoral cutaneous nerve injury occurred in 3 cases in the study group and 2 cases in the control group.Delayed wound healing occurred in 1 case in each of the two groups, and both healed after re-operation debridement and suture.Pubic branch nonunion occurred in 4 patients in the study group and 5 patients in the control group.There were no serious complications such as sciatic nerve and femoral blood vessel injury between the 2 groups, and there was no statistical significance in the incidence of complications between the 2 groups (52.4%(11/21) vs.40.0%(8/20), χ2=0.631, P=0.427).The clinical healing time of the patient was (4.5±1.3) months after surgery (range:3.0 to 8.0 months).There were no significant differences in ACE, LCE, Tonnis AI and AHI between the 2 groups (all P>0.05).At the last follow-up, there were no significant differences in VAS,Harris hip score and IHOT-12 score between the two groups (all P>0.05).The incision scars in the study group were smaller than those in the control group, and the differences in VSS and POSAS were statistically significant (all P<0.05). Conclusion:Compared with the improved Smith-Petersen approach, the improved Bikini approach has the same early clinical efficacy in the treatment of patients with developmental hip dysplasia under the age of 50, and has the advantages of smaller postoperative incision scars, more hidden and beautiful incision, and no serious complications, which is worthy of further study and promotion.

Objective:To investigate the effects of periacetabular osteotomy (PAO) in treating borderline developmental dysplasia of the hip (DDH).Methods:The patients with borderline DDH [lateral center-edge angle (LCEA): 18°-25°) who received PAO with follow-up duration for more than 2 years from January 2011 to January 2018 in our hospital were retrospectively analyzed. The patients in the control group were matched on a 1∶2 ratio based on gender, age, body mass index (BMI) and follow-up duration. There were 66 patients in the 0°≤LCEA<10° group and 66 patients in the 10°≤LCEA<18° group. The LCEA, anterior center-edge angle (ACEA), T?nnis angle, femoral head extrusion index, femoro-epiphyseal acetabular roof (FEAR) index, femoral anteversion angle, West Ontario and McMaster University (WOMAC) index and International Hip Outcome Tool (iHOT-12) were compared among the three groups before operation and the last follow-up.Results:In the preoperative 18°≤LCEA<25° group, three of 33 patients (9.1%) had LCEA, because the only imaging feature suggested acetabular dysplasia, while other parameters were evaluated within the normal range. There were 17 patients with ACEA <20° (51.5%), 24 patients (72.7%) with T?nnis angle >10°, 12 patients (36.4%) with ACEA <20° and T?nnis angle >10°. The positive rate of posterior wall signs in the 18°≤LCEA<25° group (72.7%) was lower than that in the 10°≤LCEA<18° group (77.3%) and the 0°≤LCEA<10° group (90.9%) with statistically significant difference (χ 2=6.417, P=0.040) at preoperation. The positive rate of cross sign (27.3%) and ischial spine sign (48.5%) in the 18°≤LCEA<25° group were higher than those in the 10°≤LCEA<18° group (10.6% and 18.2%, respectively, χ 2=7.002, P=0.030) and the 0°≤LCEA<10° groups (9.1% and 13.6%, respectively, χ 2=16.497, P<0.001). The FEAR index in the 18°≤LCEA<25° group (3.7±8.0) lower than that in the 10°≤LCEA<18° group (4.3±7.9) and the 0°≤LCEA<10° group (11.0±8.8) with significant difference ( F=12.703, P<0.001). In the 18°≤LCEA<25° group, postoperative LCEA increased from 20.4°±1.8° to 37.8°±7.1°, ACEA increased from 18.3°±7.8° to 36.3°±6.3°. T?nnis angle decreased from 12.7°±6.2° to -5.6°±9.2°, the femoral head extrusion index decreased from 22.9%±6.7% to 10.7%±12.2%, the WOMAC index decreased from 20.1±13.4 to 6.0±6.3, and the iHOT-12 score increased from 50.2±19.9 to 90.0±13.7. The above difference before and after surgery was statistically significant ( P<0.05). At the last follow-up, the WOMAC score in the 18°≤LCEA<25° group was 6.0±6.3, wich was less than 10°≤LCEA<18° group (9.3±9.6) and 0°≤LCEA<10° group (12.0±16.0) ( F=6.515, P=0.002). The iHOT-12 score in the 18°≤LCEA<25° group was 90.0±13.7, which was greater than 10°≤LCEA<18° group (77.7±17.3) and 0°≤LCEA<10° group (78.1±20.5) ( F=15.833, P<0.001). Conclusion:After 2 years follow-up, PAO significantly improved bone coverage of femoral head and hip function in patients with borderline DDH. Before surgery, we should pay attention to the comprehensive evaluation of different radiological parameters of the acetabulum, to make better preoperative planning.

Objective: To explore the impacts of the imaging positions on the sagittal tilt of the pelvis and the imaging parameters of the hip joint. Methods: From December 2015 to October 2016, a total of 78 female DDH patients (DDH group) who received Bernese periarticular osteotomy were enrolled, aged 28.41±9.91 years (range 18-49 years) with 135 hips. There were 21 cases on one side and 57 cases on both sides. Another 26 female volunteers without spinal and hip disease were enrolled as the control group, aged 23.54±5.58 years (range 18-49 years) with 52 hips. X-ray films of the anterior and posterior pelvis were performed in both groups. The pelvic sagittal tilt was evaluated by measurement (pubic symphysis to sacrococcygeal distance, PSSC), with lateral center-edge angle of Wiberg (LCEA), Tönnis angle (TA), and Sharp angle (angle of Sharp, SA) assessed the degree of hip dysplasia and assessed the horizontal positional relationship between the femoral head and the acetabulum using tear drop distance (TD). All data were measured twice by two measurers independently. The correlation between hip parameters and X-ray position was analyzed. Results: The average PSSC in the supine and standing positions of the control group were 53.73±16.22 mm and 36.45±14.21 mm, respectively with significant difference-17.28±8.07 mm (t=-10.913, P=0.000). The PSSC of the supine and standing positions of the DDH group were 56.76±13.54 mm and 48.62±15.44 mm, respectively with significant difference-8.13±13.02 mm (t=-5.516, P=0.000). The PSSC of the standing DDH group was larger than that in the control group. There was no significant difference in the PSSC between the two groups in the supine position. Furthermore, there were no significant difference in the supine and standing PSSC between the unilateral and bilateral DDH patients (P>0.05). In the control group, the hip in supine and standing position, LCEA averaged 30.33°±4.69° and 29.70°±3.83° (P>0.05), and TA averaged 4.05°±3.51° and 4.36°±3.07° (P>0.05), respectively. SA averaged 40.53°±4.34° and 41.79°±3.16° (P>0.05), and TD averaged 6.80±0.98 mm and 6.65±1.30 mm (P>0.05), respectively. In the DDH group, the hip in supine and standing positions, LCEA averaged 3.07°±12.07° and 1.69°±12.11° (P<0.05), and TA averaged 22.62°±9.31° and 23.82°±9.45° (P>0.05), respectively. SA averaged 48.01°±4.68° and 48.49°±4.74° (P>0.05), respectively, and TD averaged 10.51±3.51 mm and 10.93±4.23 mm (P>0.05), respectively. Conclusion From supine to standing, the pelvis backward is the main trend in sagittal plane. In standing, the pelvis of female DDH patients is forward contrast with normal women. There was no difference in pelvic tilt between unilateral and bilateral DDH patients. Female DDH patients from the supine to standing, hip coverage decreased, while the femoral head appeared horizontally outward. The hip joint of DDH patients is unstable.

Objective To report the short-term outcomes of the rotational osteotomy on the base of femoral neck in treating osteonecrosis of femoral head.Methods Ten patients (10 hips) with osteonecrosis of femoral head underwent the rotational osteotomy on the base of femoral neck between March 2014 and October 2016.There were 9 males and 1 female.The average age was 29.6 years,ranging from 18 to 42 years.There were 4 patients in right side and 6 in left side.The Association Research Circulation Osseous (ARCO) Stage was from ⅡB to ⅢC (2 cases of ⅡB,2 cases of ⅡC,1 case of ⅢA,1 case of ⅢB,4 cases of ⅢC).The following main procedures were involved in the treatment:surgical hip dislocation,the extension of retinacular soft-tissue flap to protect the main blood supply of the femoral head,anterior or posterior rotational (60°-90°) of femoral head after femoral neck osteotomy.We used three compress cannulated screws to fix the femoral neck osteotomy.The postoperative Harris hip scores (HHS),Western Ontario and McMaster College (WOMAC) score,pelvic A-P view and lateral hip view radiographic characteristics were analyzed to assess the short-term outcomes.Results The average follow-up duration was 16.3 months (7-36 months).No progressive femoral head collapse was observed in 6 patients at the last follow-up.The average post-operative intact ratio was 42.90％± 10.07％.The HHS improved from 80.00±14.93 to 86.83±6.11 (4 cases improved,1 case with no change and 1 case decreased slighdy).The WOMAC score decreased from 16.00±14.53 to 9.00±3.85 (1 cases increased,1 case with no change and 4 case decreased).The remaining 4 cases,however,had the progression of the femoral head collapse.The average post-operative intact ratio was 16.57％±6.57％.The HHS decreased from 77.75±14.66 to 60.75±17.54 (1 case improved slightly and 3 cases decreased).The WOMAC score increased from 12.75±5.06 to 22.50±8.81 (4 cases increased).Conclusion The rotational osteotomy on the base of femoral neck not only shifts the necrosis area away from weight-bearing region but also improves the post-operative intact ratio.Patients with ARCO stage ⅡB-ⅢB may achieve remission of symptoms and improvement of hip function by this surgical technique.However,for patients with ⅢC stage,we should conduct preoperative design to make sure whether the surgery is worth doing or not.Some patients may suffer from post-operative progression collapse of the femoral head.

Objective To investigate the clinical efficiency and safety of femoral head reduction osteotomy for young patients with coxa magna or coxa plana.Methods Between June 2012 and September 2015,the clinical characteristics of 12 patients (13 hips) with coxa magna or coxa plana who underwent femoral head reduction osteotomy were analyzed retrospectively.There were 6 males (7 hips) and 6 females (6 hips) with average age 18.1 years (range,10-25 years).The etiology of the femoral head deformity was multiple epiphyseal dysplasia in 6 hips and Legg-Calvé-Perthes sequela in 7 hips.The head reduction osteotomy was conducted through the surgical hip dislocation approach combined with extended retinacular soft-tissue flap extending technique.All patients underwent simultaneous periacetabular osteotomy and relative lengthening of the femoral neck,of which four also underwent proximal femur derotational osteotomy.All patients received the standardized rehabilitation procedures.The postoperative complications,gaits,the range of motion (ROM) of the hip,Harris hip scores,iHOT scores and VAS were analyzed postoperatively.In addition,the lateral center-edge (LCE) angle,sphericity index and coverage rate of femoral head were assessed as well.Results The average follow-up duration was 28.8 months (range,12-45 months).All patients achieved osteotomy healing of the femoral head and greater trochanter with average healing time 3.7 months (range,3-7 months).Nine of 12 patients had significant gaits improvement.The Harris hip scores (81.08± 12.36 vs.88.38 ± 8.96,t=2.41,P=0.033),iHOT score (51.90± 15.07 vs.67.69±8.70,t=3.63,P=0.003),LCE angle (-1.82°±16.57° vs.36.02°±7.72°,t=10.52,P=0.000),sphericity index of anteroposterior pelvic radiographs (71.08％± 10.32％ vs.81.22％±8.61％,t=7.17,P=0.000) and the coverage index (48.79％±11.85％ vs.87.46％± 10.44％,t=8.56,P=0.000) were all significantly improved when compared to those preoperatively.The VAS score (4.46± 2.37 vs.1.23±0.93,t=4.25,P=0.001) was significantly decreased when compared with that preoperatively.However,for the sphericity index of 65° false profile (78.96％± 10.39％ vs.80.36％±8.42％,t=0.411,P=0.688) and the average hip ROM (264.62°± 32.05° vs.255.00°±40.31°,t=0.89,P=0.391),they did not achieve statistical significant difference.One case of femoral head necrosis site was localized at the lateral-superior part of femoral head,and there was no progression after 3 years follow-up.Moreover,no revision or total hip arthroplasty were observed due to other complications (osteoarthritis,hip pain or non-union).Conclusion The femoral head reduction osteotomy can correct deformity,improve femoral head sphericity,relieve pain and improve gaits and hip function.This procedure leads to satisfied clinical outcomes for patients with coxa magna or coxa plana in early follow-up.