Objective To compare the efficacy of tibial tuberosity osteotomy (TTO) combined with medial patellofemoral ligament reconstruction (MPFLR) with simple TTO in treatment of recurrent patella dislocation associated with patella alta.Methods From July 2010 to December 2015,50 patients with recurrent patella dislocation and patella alta were included in this study.There were 15 males and 35 females with an average age of 20.6 years.These patients received surgical treatment and their clinical data were collected and retrospectively analyzed by case-control study.According to surgical methods,patients were divided into TTO group (32 cases) and MPFLR + TTO group (18 cases).The differences between preoperative status and postoperative status were evaluated by knee function scores including Tegner,international knee documentation committee (IKDC),Kujala scores,knee injury and osteoarthritis outcome score (KOOS).Patellar stability was checked at the last follow-up visit.Results The TTO group and MPFLR + TTO group were followed up for (50.9 ± 17.8) months and (22.3± 10.1)months,respectively.Two patients occurred recurrent dislocation in TTO group,who showed positive in both extrapolation test and extrapolation apprehension test at 0°flexions of knee.All patients in MPFLR + TTO group did not occur recurrent dislocation,who showed negative in both extrapolation test and extrapolation apprehension test at 0° flexions of knee.There was no significant difference between preoperative and postoperative results in TTO group in Tegner score (P ＞ 0.05),KOOS scores in pain and daily life activities subdomains (P ＞ 0.05),while differences in the rest of scores were statistically significant (P ＜ 0.05).Compared with TFO group,the differences of all scores were statistically significant (P ＜ 0.05) and KOOS scores in the pain and daily life activities subdomains were significantly improved postoperatively in MPFLR + TTO group P ＜0.05).Conclusions For patients with recurrent patellar dislocation associated with patella alta,both surgical methods are found to be effective.Postoperative improvements in pain and daily life activities are less obvious in TTO.While postoperative improvements in pain and daily life activities in MPFLR + TTO are superior to those of TTO.

Objective:To explore the effects of mechanical factors on the morphology of the growth plate and proximal femur development, in order to provide a mechanical basis for the mechanism of Cam lesions in femoral acetabular impingement (FAI).Methods:Using CT scan data of hip joint from adolescents, we constructed three-dimensional finite element models of normal and extended proximal femoral epiphyseal growth plates. Dynamic mechanics and position data from daily activities (walk, stand on one and two feet, go upstairs and downstairs, sit and stand up, squat and stand up) and basketball layup drills were collected from five healthy volunteers using the Vicon system. The mean values of femoral head mechanical loads and positions at peak values, movement onset, and termination were selected for finite element analysis to observe the distribution of equivalent stress, normal stress, and shear stress on the two growth plate models under different activity modes.Results:Successful construction of three-dimensional finite element models for normal and extended proximal femoral epiphyseal growth plates was achieved. Mechanical load values and spatial positions of the femoral head during daily activities and layup movements were obtained. In daily activities, peak equivalent stress values for normal and extended growth plates ranged from 1.6 to 11.0 MPa; compressive stress ranged from 1.7 to 12.0 MPa; tensile stress ranged from 0.5 to 10.0 MPa; and shear force ranged from 0.4 to 7.1 MPa. The compressive stress during walking, standing on one or both feet, going up and down stairs, sitting and standing, and squatting was concentrated in the central and lateral areas; tensile stress was concentrated in the central and medial areas; shear force was concentrated in the medial area and the anterior and posterior edges of the growth plate. During a layup, the compressive stress in the center, outer upper side, and medial edge of the growth plate of the normal model was notably concentrated, with peaks fluctuating between 5.5-19.0 MPa, 5.7-11.0 MPa, and 5.4-7.3 MPa respectively; tensile stress and shear force were concentrated at the inner and outer edges as well as in the central area, with peaks fluctuating between 3.0-24.0 MPa and 3.0-26.0 MPa respectively, these values were significantly different from those observed during daily activities. For the elongated growth plate, compressive stress was concentrated at the central and lateral edges with peaks fluctuating between 17.0-41.0 MPa and 17.0-38.0 MPa respectively; simulated shear stress and tensile stress showed significant concentration at peaks fluctuating between 4.9-34.0 MPa, also significantly different from those observed during daily activities.Conclusion:The difference in mechanical distribution between daily activities, basketball layup training, as well as between normal and extended growth plates may be the mechanical initiating factor in the development of extended growth plates and the formation of Cam lesions, it may be the mechanical initiating factor for the development of extended growth plates and the collision of Cam lesions in FAI.

OBJECTIVETo observe autograft of femoral head for acetabular reconstruction in total hip arthroplasty(THA)without shortening femoral osteotomy for developmental dysplasia of the hip (DDH) with complicated deformity.

METHODSA case series of 18 Crowe type-III-IV DDH patients (19 hips) with osteoarthritis between December 2004 and October 2010 was reported. There were 2 male and 16 female patients. Mean age was 34.3 years (19-44 years) and limb shortening 4.5 cm (3.0-6.2 cm), and preoperative Harris score was 40 ± 17. All cases were accomplished through posterolateral approach by the same surgeon and underwent the procedure of acetabular reconstruction using a bulk femoral head autograft and periarticular soft tissue releases(dissection of the entire articular capsule, scar tissues and osteophytes), but had no procedure of shortening by subtrochanteric transverse osteotomy. Design data through paired t-test compared the preoperative and postoperative Harris scores, also the radiographic observation, in order to asses the clinical efficacy of acetabular reconstruction, while observing the length of limb lengthening, complications and function.

RESULTSGraft coverage of cases in the group were 16%-47% (mean, 26%), with 17 mm of the socket uncovered during operative evaluation. All patients were followed-up for 14-56 months (mean, 34.6 months). The lengthening of the affected limb was 2.9-4.6 cm (mean, (3.6 ± 0.7)cm). The limb-length discrepancy was 0-1.2 cm (mean, (0.6 ± 0.3)cm) after THA. The offset of the affected limbs was 26.4-34.3 cm(mean, (30.5 ± 1.6)cm). The postoperation radiography showed good position of the prosthetic components and coverage of the socket after bone graft was full. All patients had no static contraction abnormality of muscle in the affected limb. Three patients with numbness in lateral leg after the procedure recovered completely in one months. No other complication was observed except heterotopic ossification in 1 case. At the last follow-up examination, Harris hip score was 86 ± 11. There was statistical significance compared with the preoperative score (t = 5.86, P < 0.01) , and no revision was needed in all patients.

CONCLUSIONAutograft of femoral head for acetabular reconstruction in THA without shortening femoral osteotomy for developmental dysplasia of the hip (DDH) is an effective procedure to reconstruct acetabulum and improve the socket bone coverage.

Acetabulum ; surgery ; Adult ; Arthroplasty, Replacement, Hip ; Female ; Femur Head ; transplantation ; Hip Dislocation, Congenital ; surgery ; Humans ; Male ; Reconstructive Surgical Procedures ; Retrospective Studies ; Young Adult