| Objective:To investigate the characteristics of lower limb deformity in patients with unilateral developmental dislocation of the hip(UDDH)and the clinical results of capsular arthroplasty in the treatment of UDDH patients.We also aim to study the theoretical basis of this hip-preserving surgery by evaluating the ’interposed hip capsule metaplasia on the weight-bearing area postoperatively.Materials and Methods:1、Clinical results of capsular arthroplasty in the treatment of UDDH patients:We retrospectively evaluated all patients who had the capsular arthroplasty from June 2012 to September 2016 in our department.The general characteristics,comorbidities,surgical history,preoperative radiological characteristics,surgical situation and follow-up data were reviewed to analysis the clinical results,the factors associated with postoperative hip function as well as the complications of capsular arthroplasty.2.The metaplasia of the interposed hip capsule on the weight-bearing area:We conduct the animal experiment and made the radiographic and microscopic observations after operation.Besides,we performed the histological examination of the intraoperative specimens from a patient who had total hip replacement 41.5 months after a capsular arthroplasty and from a patient who had the hip subluxation with the capsule interposed between the femoral head and the false acetabulum.3、Lower-limb-length of UDDH patients:We reviewed the radiographic data of all patients with unilateral DDH who met the inclusion criteria from March 2011 to May 2016.These data included femoral length(FL),tibial length(TL),skeletal limb length(SLL),and distance from the lesser trochanter to the tibial plafond(LT-TP).4、Lower limb alignment in UDDH patients:We reviewed the radiographic data of 76 patients who met the inclusion criteria,including the hip-knee-ankle angle(HKA),mechanical lateral distal femoral angle(mLDFA),anatomical lateral distal femoral angle(aLDFA),mechanical proximal tibial angle(MPTA),and lateral distal tibial angle(LDTA).Results:1、Clinical results:A total of 59 patients(10 males and 49 females)with an average age of 16.8y were followed by a mean of 32.1 months.These patients had a mean hip Harris score of 83.4,WOMAC score of 12.3 at latest followup.The capsular quality was associated with hip function and patient satisfaction.2、Metaplasia of the interposed capsule:Histological examination showed that the interposed tissue became fibrocartilage on the weight-bearing area,but not on the non-weight bearing area.3、Lower-limb-length:Sixty-seven patients(12 male and 55 female)were included.The TL,SLL,and LT-TP were significantly greater on the ipsilateral side,compared with the contralateral side,in 51 patients(76%),43 patients(64%),and 52 patients(78%),respectively,with the values on the ipsilateral side exceeding those on the contralateral side by an average of 4.6 mm(range,0.4 to 17.5 mm),7.0 mm(range,0.3 to 21.1 mm),and 10.0 mm(range,1.1 to 28.8 mm),respectively.The FL did not differ significantly between the 2 sides(p = 0.562).4、Lower limb alignment:The valgus alignment on ipsilateral side was most frequently seen in both Hartofilakidis type Ⅱ(51.3%)and type Ⅲ groups(67.6%),whereas for the contralateral side,the neutral alignment in type Ⅱ group(69.2%)and varus alignment in type III group(51.4%)were most commonly observed.Both the mLDFA and aLDFA of the ipsilateral side were significantly smaller than the contralateral side.Conclusion:We confirmed the efficacy of the capsular arthroplasty in the treatment of UDDH patients with low incidence of complications.Both the complex surgical technique and the lower limb deformities should be taken into consideration during surgery.The capsular quality is one of the most important factor that associated with the clinical result.We also found the interposed tissue became fibrocartilage on the weight-bearing area,so the indications should be choose strictly according to the capsular quality. |
PDF Full Text Request