Study of three-dimensional morphology of the proximal femur in developmental adult dysplasia of the hip suggests that the on-shelf modular prosthesis may not be an ideal choice for patients with Crowe type IV hips

The Effect of the Morphology of the Femur and Acetabulum in Dysplastic Hips on the Selection of Arthroplasty Femoral Implants: A Computer Tomography-Based Study

OBJECTIVES

Due to the technical challenges associated with femoral reconstruction in total hip arthroplasty for patients with developmental dysplasia of the hip (DDH), the exact indications for using femoral modular stems, despite their satisfactory clinical outcomes, remain poorly investigated. This study sought to assess the morphology of the femur and acetabulum, and to investigate the discriminative ability of femoral anteversion (FA), acetabular anteversion (AA), and combined anteversion (CA) on the selection of femoral modular stem in dysplastic hips.

METHODS

Retrospective data were collected from multiple centers on a total of 230 cases who underwent THA due to DDH from January 1, 2020, to March 1, 2023. There were 46 males and 184 females, with an average age of 51.57 ± 14.87. Patients were stratified according to Crowe and Eftekhar classifications. FA, AA, and CA were measured using computed tomography (CT). The distribution of these indices in different grades of dysplastic hips was compared, and the correlation between these indices and the selection of femoral modular stem was analyzed. Receiver operating characteristic (ROC) and likelihood statistics were performed to investigate the discriminating and predictive value of each index in selecting modular stem.

RESULTS

Two hundred and thirty hips were included in the study. FA increased as the subluxation percentage increased: type I, 21.5°; type II, 28.6°; type III, 34.9°; and type IV, 39.7°. AA was smaller in type I (16.9°) and higher in types II, III, and IV (18.9-22.6°). The area under the curve for the modular stem was 0.87 for FA, 0.86 for CA, and 0.65 for AA. The optimal cutoff values were FA > 32.6°, CA > 50.7°, and AA > 23.3°.

CONCLUSION

Excessive AA and femoral anteversion FA were observed in Crowe types II, III, and IV cases. FA and CA demonstrated strong discriminative ability and predictive value in the selection of a modular stem. The best cutoff values were ≥32.6° for FA and ≥50.7° for CA in discriminating the use of modular stem. Surgeons may contemplate the use of a modular stem when the preoperative evaluation approaches the cutoff value.

Total Hip Arthroplasty Combined with Proximal Femoral Reconstruction Effectively Treats Severe Hip Deformities: A Novel Osteotomy Technique

OBJECTIVE

Total hip arthroplasty (THA) combined with proximal femoral reconstruction is a novel osteotomy technique developed to address severe hip deformities. There is a paucity of robust clinical and radiological evidence regarding the outcomes of this novel osteotomy technique. This study aimed to evaluate the clinical and radiological outcomes of THA combined with proximal femoral reconstruction during the early follow-up.

METHODS

This is a retrospective case series of 63 hips who underwent THA combined with proximal femoral reconstruction at a single institution between January 2020 and July 2023. The mean age of patients was 39.6 ± 12.6 years. The mean follow-up was 25.6 ± 3.8 months. Surgical characteristics and perioperative variables were evaluated to assess the efficacy of this technique. Harris hip score (HHS) was utilized to evaluate hip function. Leg length discrepancy (LLD) was evaluated in X-ray. The incidence of major adverse events including deep vein thrombosis (DVT), osteolysis, nonunion of the osteotomy, intraoperative femoral fracture, and infection was also evaluated. Paired-samples t-test was used to compare preoperative and postoperative HHS and LLD.

RESULTS

The mean operative time was 125.1 min. The mean size of the acetabular components used was 45.2 mm, and the stem size was 7.5. The primary friction interface was ceramic-on-ceramic, accounting for 92.1% of cases. The average length of hospital stay was 8.5 days. The mean cost of treatment was 46,296.0 Yuan. There was a significant improvement in postoperative HHS (p < 0.001) and LLD (p < 0.001) compared to preoperative values. The incidence of deep venous thrombosis was 4.8%; osteolysis rates for the cup and stem were 4.8% and 6.4%, respectively. The non-union and dislocation rates were 1.6% and 3.2%, respectively. There was no incidence of postoperative infection.

CONCLUSION

The novel osteotomy surgical procedure yields reliable and impressive clinical and radiological outcomes, with minimal complications. We advocate for its use in complex primary THA cases involving severe proximal femoral deformities.

[Three-dimensional morphological study of the effect of false acetabulum on the femoral structure in Crowe type developmental dysplasia of the hip]

Objective

To explore the effect of false acetabulum on the development and anatomical morphology of proximal femur in Crowe type Ⅳ developmental dysplasia of the hip (DDH), providing a theoretical basis for the development of femoral reconstruction strategy and prosthesis selection for total hip arthroplasty.

Methods

The medical records of 47 patients (54 hips) with Crowe type Ⅳ DDH between February 2008 and March 2020 were retrospectively analyzed, of which 21 patients (26 hips) were Crowe type Ⅳa (type Ⅳa group) and 26 patients (28 hips) were Crowe type Ⅳb (type Ⅳb group). There was no significant difference in general data such as gender, age, height, weight, body mass index, and side between the two groups ( P>0.05), which were comparable. The height of femoral head dislocation, the height of pelvis, and the proportion of dislocation were measured based on preoperative anteroposterior pelvic X-ray film. Based on the preoperative femoral CT scan data, the anatomical parameters of the femur and femoral medullary cavity were measured after three-dimensional reconstruction using Mimics19.0 software to calculate the canal fare index; and the femoral medullary cavity parameters were matched with the modular S-ROM prosthesis parameters.

Results

The results of X-ray film measurement showed that the height of femoral head dislocation and the proportion of dislocation in type Ⅳa group were significantly higher than those in type Ⅳb group ( P<0.05). There was no significant difference in the height of pelvis between the two groups ( P>0.05). The results of CT three-dimensional reconstruction measurements showed that compared with the type Ⅳb group, the type Ⅳa group had less isthmus height, smaller femoral head, shorter femoral neck, narrower neck-shaft angle, increased anteversion angle, and higher greater trochanter, and the differences were significant ( P<0.05). There was no significant difference in the height of femoral head, femoral offset, and height difference between greater trochanter and femoral head between the two groups ( P>0.05). There was no significant difference in the mediolateral width (ML), anteroposterior width (AP), and diameter of the isthmus (Ci level) and the AP of the medullary cavity in the plane 40 mm distal to the most prominent point on the medial side of the lesser trochanter (C -40 level) ( P>0.05), and the size of medullary cavity was significantly smaller in type Ⅳa group than in type Ⅳb group at the other levels ( P<0.05). Compared with the type Ⅳb group, the difference between the outer diameter of the prosthetic sleeve and the diameter of the medullary cavity fitting circle in the plane where the center of femoral head rotation was located from the medial most prominent point of the lesser trochanter (C 0 level) in type Ⅳa group was smaller, and the proportion of negative values was greater ( P<0.05). The difference between the longest diameter of the prosthetic sleeve triangle and the ML of the medullary cavity in the plane 10 mm proximal to the most prominent point on the medial side of the lesser trochanter (C +10 level) in type Ⅳa group was smaller, and the proportion of negative values was greater ( P<0.05).

Conclusion

False acetabulum has a significant impact on the morphology of the proximal femur and medullary cavity in patients with Crowe type Ⅳ DDH, and the application of three-dimensional reconstruction technique can accurately evaluate the femoral morphology and guide the selection of femoral prosthesis.

Three-dimensional morphological study of the proximal femur in Crowe type IV developmental dysplasia of the hip

Background

When performing femoral reconstruction in patients with Crowe type IV developmental dysplasia of the hip (DDH), anatomical deformity presents many technical challenges to orthopedic surgeons. The false acetabulum is suggested to influence load transmission and femoral development. The aim of this study was to describe the morphological features of dysplastic femurs in Crowe type IV DDH and further evaluate the potential effect of the false acetabulum on morphological features and medullary canal of Crowe type IV femurs.

Methods

We analyzed preoperative computed tomography scans from 45 patients with 51 hips (25 hips without false acetabulum in the IVa group and 26 hips with false acetabulum in the IVb group) who were diagnosed with Crowe type IV DDH and 30 normal hips in our hospital between January 2009 and January 2019. Three-dimensional reconstruction was performed using Mimics software, and the coronal femoral plane was determined to evaluate the following parameters: dislocation height, dislocation ratio, height of the femoral head (FH), height of the greater trochanter (GT), GT–FH height discrepancy, height of the isthmus, neck-shaft angle, femoral offset and anteversion of the femoral neck. The mediolateral (ML) width, anterolateral (AP) width and diameter of medullary canal of the proximal femur were measured on the axial sections. Further, canal flare index (CFI), metaphyseal-CFI and diaphyseal-CFI were also calculated.

Results

Compared with the normal femurs, the Crowe type IV DDH femurs had a higher femoral head, larger GT–FH height discrepancy, larger femoral neck anteversion, higher isthmus position and smaller femoral offset. Dislocation height and dislocation rate were significantly larger in the IVa DDH group (65.34 ± 9.83 mm vs. 52.24 ± 11.42 mm). Further, the IVb femurs had a significantly lower isthmus position, larger neck-shaft angle and smaller femoral neck anteversion than IVa femurs. The ML, AP canal widths and the diameter of medullary canal in both DDH groups were significantly smaller than the normal group. Dimensional parameters of IVa femurs were also narrower than IVb femurs in most sections, but with no difference at the level of isthmus. According to the CFIs, the variation of proximal medullary canal in IVb femurs was mainly located in the diaphyseal region, while that in IVa femurs was located in the whole proximal femur.

Conclusions

High dislocated femurs are associated with more anteverted femoral neck, smaller femoral offset and narrower medullary canal. Without stimulation of the false acetabulum, IVa DDH femurs were associated with higher dislocation and notably narrower medullary canal, whose variation of medullary canal was located in the whole proximal femur.

The Influence of Femoral Proximal Medullary Morphology on Subtrochanteric Osteotomy in Total Hip Arthroplasty for Unilateral High Dislocated Hips

Objective

To evaluate the predictive values of femoral proximal medullary morphology for the use of subtrochanteric osteotomy (STO) in unilateral Crowe IV developmental dysplasia of the hip (DDH).

Methods

Ninety four patients with unilateral Crowe type IV DDH (59 hips in STO group and 35 hips in the non‐STO group) between April 2008 and June 2019 were enrolled. All patients underwent THA using the Pinnacle acetabular shell, ceramic liner and femoral head, the S‐ROM stem with proximal sleeve. Three parameters on the standard anteroposterior hip radiographs were measured: the widths of medullary canals at 20 mm above the center of lesser trochanter (CLT)，20 mm below the CLT and the isthmus. Canal flare index (CFI), metaphyseal canal flare index (MCFI), diaphyseal canal flare index (DCFI) were calculated. A S‐ROM femoral stem was used in all patients during total hip arthroplasty (THA).

Results

The CFI and DCFI in the STO group were lower than those in the non‐STO group. However, there was no statistical difference in MCFI between the two groups. The receiver operating characteristic (ROC) curves shown that DCFI had the highest area under the curve (AUC), at 0.885. This was followed by the CFI, which had an AUC of 0.847. The AUC of MCFI was 0.579. The optimal threshold for DCFI was 1.44, which lead to a sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 0.771, 0.898, 0.869, and 0.818, respectively. For CFI, the optimal threshold was 3.28, resulting in a sensitivity, specificity, PPV, and NPV of 0.829, 0.729, 0.878, and 0.644, respectively.

Conclusions

The DCFI and CFI may be potent indicators in predicting the use of STO in unilateral Crowe IV DDH. The optimal threshold for CFI and DCFI were 3.28 and 1.44 and had good sensitivity and specificity for predicting the use of STO during THA.

The Three-Dimensional Morphology of Femoral Medullary Cavity in the Developmental Dysplasia of the Hip

OBJECTIVE

This study aimed to assess the morphology of the femoral medullary canal in subjects with developmental dysplasia of the hip (DDH) with the intent of improving the design of femoral stems in total hip arthroplasty.

METHODS

Computed tomography images of 56 DDH hips, which were classified into Crowe I to Crowe IV, and 30 normal hips were collected and used to reconstruct three-dimensional morphology of the femoral medullary cavity. Images of twenty-one cross sections were taken from 20 mm above the apex of the lesser trochanter to the isthmus. The morphology of femoral cavity was evaluated on each cross section for the longest canal diameter, the femoral medullary torsion angle (FMTA), and the femoral medullary roundness index (FMRI).

RESULTS

The Crowe IV group displayed the narrowest medullary canal in the region superior to the end of the lesser trochanter, but then gradually aligned with the medullary diameter of the other groups down to the isthmus. The FMTA along the femoral cavity increased with the severity of DDH, but the rate of variation of FMTA along the femoral canal was consistent in the DDH groups. The DDH hips generally showed a larger FMRI than the normal hips, indicating more elliptical shapes.

CONCLUSION

A femoral stem with a cone shape in the proximal femur and a cylindrical shape for the remainder down to the isthmus may benefit the subjects with severe DDH. This design could protect bone, recover excessive femoral anteversion and facilitate the implantation in the narrow medullary canal.

Comparison of the modified Smith-Petersen (S-P) and ilioinguinal (I-I) approaches for periacetabular osteotomy in adult developmental dysplasia of the hip: a retrospective study

Background

Adult developmental dysplasia of the hip is an untreated congenital hip dysplasia that results in adult hip pain. One of the usual and effective methods for the treatment of this condition is periacetabular osteotomy. However, which approach is better between the modified S-P and the I-I approaches is still unclear and controversial.

Method and materials

We retrospectively assessed our experience with the modified S-P and the I-I approaches by inquiring and evaluating intraoperative blood loss, postoperative radiographic material, postoperative function of the hip, and related complications from July 2014 to January 2019.

Results

A total of 61 patients with adult developmental dysplasia of the hip were enrolled, and 33 patients were divided into a modified S-P group and 28 patients were divided into I-I group. The operation time and blood loss of group I-I were higher than that of group modified S-P. Other clinical and radiographic indexes showed no statistical significance between group the modified S-P and I-I groups.

Conclusion

There is no significant difference in the improvement of the function of the hip at the post-operation stage, but group I-I may require more operation time and blood loss at the intra-operation stage.

Total hip arthroplasty combined with subtrochanteric shortening osteotomy for Crowe type IV hip dysplasia in dwarfism: a case report

Dwarfism is a condition of extreme short stature. Total hip arthroplasty (THA) in patients with dwarfism is a very demanding procedure due to their specific joint deformity and small bone size, which increases the technical difficulty of the THA procedure in such patients with hip dysplasia. This current case report describes a 29-year-old female patient that was admitted due to shortening of the right lower limb, as compared with the contralateral side, which had been present for 18 years. She also complained of pain in the right hip that had been present for 2 months. The hip pain was aggravated by physical exertion, but relieved by rest. She had pituitary dwarfism without mental retardation or delayed sexual development and Crowe type IV dysplasia of the right hip. A THA combined with femoral shortening osteotomy was undertaken, which resolved the pain symptoms and improved her ability to undertake activities of daily living such as walking without pain. Dwarfism with hip dysplasia is a rare but extremely challenging problem that can be successfully treated with THA combined with femoral shortening osteotomy using an S-ROM stem.

Level of osteotomy is relevant to obtain better union and clinical results in patients with severe hip dysplasia operated on with total hip arthroplasty and shortening osteotomy using a cementless, rectangular femoral component

INTRODUCTION AND OBJECTIVE

Total hip arthroplasty with rectangular femoral component and transverse osteotomy for patients with Crowe type 3 or 4 dysplasia yields successful results with varying radiological findings. This study aims to investigate the surgery and patient related factors associated with successful clinical and radiological results.

PATIENTS AND METHODS

Fifty hips of 41 patients were retrospectively examined. Length and percentage of the stem passing the osteotomy level and canal fill ratio were measured. Radiological findings such as radiolucent lines (RL) around the stem, hypertrophic callus or an identifiable osteotomy line on X-ray images were assessed. All clinical and radiological results were analyzed for any significant association.

RESULTS

Mean stem length and percentage passing the osteotomy level were 6.4 cm (± 0.7) and 51% (± 6). Presence of an identifiable osteotomy line was positively associated with the increasing length of the stem passing the osteotomy level and with a lower HHS (p < 0.05). RL around the stem were associated with a lesser reduction in VAS score (p < 0.05).

CONCLUSION

Rectangular femoral stem conveniently accommodate the proximal femur in severely dysplastic hips. An upper limit for the femoral stem exists to obtain better bony union and higher HHS. RL around the stem are clinically relevant and is associated with a worse VAS score at the latest follow-up.

Comparison of two different on-shelf femoral stems for Crowe type IV developmental dysplasia of the hip

Objective

This study was performed to evaluate the proximal anatomical compatibility of stems for treatment of Crowe IV developmental dysplasia of the hip (DDH) using a previously developed three-dimensional comparison technique.

Methods

Patients with Crowe IV DDH who underwent computed tomography were retrospectively analyzed. The femoral medullary canals were three-dimensionally reconstructed, and models of cementless modular (S-ROM; DePuy Synthes) and conical (Wagner Cone; Zimmer Biomet) implants were used for virtual implantation. The negative point percentages (NPPs) were applied to verify fitting. The average distance (deviation) and the root mean square of the distance (RMSd) were used to quantify geometric compatibilities.

Results

Four (16.7%) and 12 (50.0%) femoral medullary canals could not be fitted properly with either the modular or conical implant. The NPPs in the distal comparison region were significantly greater in the conical than modular group. The deviation was significantly smaller in the modular than conical group. The RMSd was also significantly smaller in the modular than conical group.

Conclusions

Compared with conical implants, modular implants might be more effectively used in patients with Crowe type IV DDH. However, some Crowe IV DDH femurs with severe deformity cannot be fitted with either of these two on-shelf implants.

The Effect of the False Acetabulum on Femoral Proximal Medullary Canal in Unilateral Crowe Type IV Developmental Dislocation of the Hip

Purpose

To investigate the effect of the false acetabulum on femoral proximal medullary canal in unilateral Crowe type IV developmental dislocation of the hip (DDH) patients on anteroposterior radiographs.

Patients and Methods

We measured the following parameters of DDH and contralateral normal hip (CNH) of proximal morphology of femurs on 65 patients with unilateral Crowe type IV DDH (30 hips with no false acetabulum (type IVA) and 35 hips with a false acetabulum (type IVB)) in our hospital between September 2009 and July 2019 on anteroposterior radiographs: the widths of medullary canals at 20 mm above the center of lesser trochanter (CLT), 20 mm below the CLT and the isthmus. Canal flare index (CFI), metaphyseal canal flare index (MCFI), diaphyseal canal flare index (DCFI) were calculated.

Results

The values of CFI of DDH and CNH in unilateral type IVA patients were 2.8 and 4.4, respectively (p < 0.001), and those in type IVB patients were 3.9 and 4.6, respectively (p < 0.001). The MCFIs of DDH and CNH in type IVA group were 2.2 and 2.3, respectively (p = 0.032), and those in type IVB group were 2.4 and 2.4, respectively (p = 0.242). The DCFIs of DDH and CNH in type IVA group were 1.3 and 1.9, respectively (p < 0.001), and those in type IVB group were 1.7 and 1.9, respectively (p = 0.002).

Conclusion

The false acetabulum stimulated the development of the proximal femur in Crowe type IV DDH. The variation of the femoral proximal medullary canal in type IVA DDH mainly occurred at the metaphyseal and proximal diaphyseal levels, and that in type IVB DDH mainly occurred at the proximal diaphyseal level.

[Total hip arthroplasty with Wagner Cone stem and subtrochanteric shortening osteotomy in treatment of Crowe developmental dysplasia of hip in adults]

Objective

To investigate the short-term effectiveness of total hip arthroplasty with Wagner Cone stem combined with subtrochanteric shortening osteotomy for adult patients with Crowe Ⅳ developmental dysplasia of the hip (DDH).

Methods

A clinical data of 18 patients (20 hips) with Crowe Ⅳ DDH between January 2015 and June 2017 was retrospectively analyzed. There were 5 males (6 hips) and 13 females (14 hips), with an average age of 42 years (range, 20-67 years). There were 18 cases with unilateral DDH and 2 cases with bilateral DDHs. The "4" sign and Trendelenburg sign of affected hip were positive. Preoperative Harris score and visual analogue scale (VAS) score were 41.95±6.90 and 5.05±1.15, respectively. The length discrepancy was (4.76±2.59) cm in patients with unilateral DDH. And the lengths of bilateral lower limbs in patients with bilateral DDH were equal. The acetabular anteversion angle, femoral anteversion angle, and combined anteversion angle were (32.82±2.79), (46.18±6.80), and (79.01±7.54) °, respectively. All patients were treated by total hip arthroplasty with Wagner Cone stem and subtrochanteric shortening osteotomy. The length of osteotomy ranged from 2.0 to 3.5 cm (mean, 2.38 cm).

Results

The operation time was 116-161 minutes (mean, 138.4 minutes); the volume of intraoperative blood loss was 600-1 200 mL (mean, 795 mL); the volume of drainage after operation was 100-630 mL (mean, 252 mL). All incisions healed by first intention. The symptom of sciatic nerve injury occurred in 1 case and relieved after symptomatic treatment. All patients were followed up 12-29 months (mean, 18.4 months). The "4" sign and Trendelenburg sign of affected hip were negative. The Harris score and VAS score at last follow-up were 87.50±5.06 and 0.75±0.85, respectively. The acetabular anteversion angle, femoral anteversion angle, and combined anteversion angle were (16.21±4.84), (18.99±2.55), and (35.20±5.80)°, respectively. There were significant differences in above indexes between pre- and post-operation ( P<0.05). The length discrepancy was (0.72±0.70) cm in patients with unilateral DDH, which was significant shorter than the preoperative value ( t=7.751, P=0.000). And the lengths of bilateral lower limbs in patients with bilateral DDH were equal. X-ray films showed that the osteotomy of femur healed at 3-6 months (mean, 4.1 months) without the signs of loosening, sinking, osteolysis, and dislocation.

Conclusion

Total hip arthroplasty with Wagner Cone stem and subtrochanteric shortening osteotomy can obviously improve the hip joint function and restore the length of lower limb. The short-term effectiveness is satisfactory, but the long-term effectiveness and survival rate of prosthesis need to be further observed.

Preoperative Planning for Total Hip Arthroplasty for Neglected Developmental Dysplasia of the Hip

Developmental dysplasia of the hip (DDH) is accompanied by morphological alterations on both the acetabular and the femoral side. Total hip arthroplasty (THA) provides effective treatment in cases of neglected DDH but requires elaborate preoperative planning. To determine the morphological changes resulting from the dysplasia, the anatomic acetabular position, the height of the femur head dislocation, the height of the femur head dislocation, and the combined anteversion must all be established. In addition, a vital and complicated process of strategizing leg length balance must be conducted in cases of severe DDH. Each type of leg length discrepancy (LLD), including bony and functional and anatomical LLD, should be evaluated in the context of the presence or absence of a fixed pelvic tilt. Moreover, with severe unilateral dislocated hips, a more inferior change in the original rotational center of the hip must be accounted for. Due to these multiple morphological changes, the accurate size of the prosthesis and the cup position are difficult to predict. In comparison with other methods, CT scan‐based 3‐dimensional templating provides the best accuracy. Despite the presence of anatomic alterations, various types of acetabular and femoral prostheses have been developed to treat hip dysplasia. Both cemented and cementless cups are used in DDH cases. In DDH accompanied by insufficient acetabular bone stock, a cemented cup combined with bone graft provides a reliable treatment. Monoblock stems can be used when the combined anteversion is less than 55°, and a modular stem system when this parameter is greater than 55°. Customized stems can be designed for DDH coupled with severe proximal femoral distortion. A ceramic‐on‐ceramic bearing is considered optimal for young DDH patients.

Gender and disease severity determine proximal femoral morphology in developmental dysplasia of the hip

In this computed tomography (CT) morphological study we describe the way the proximal femoral morphology differs with worsening degrees of developmental dysplasia of the hip (DDH) and describe gender differences in patients with DDH. Forty-nine male patients with DDH were matched with 49 females with DDH, using age and the Crowe classification of DDH severity. The femoral length, anteversion, neck-shaft angle, offset, neck length, canal-calcar ratio, canal flare index, lateral center-edge angle, alpha angle, pelvic tilt, and pelvic incidence were measured for each patient on their pre-operative CT scans, prior to total hip arthroplasty surgery. Femoral anteversion and neck length were 16° and 47 mm, 25°and 36 mm, 26° and 43 mm, and 44° and 36 mm, for Crowe I and III males and Crowe I and III females, respectively. The mean male anteversion was 22° (±14), compared to 30° (±15.5) in females (p = 0.02, Confidence Interval: 1.6-14.9). Gender differences in femoral length, neck length and offset lost significance when height-normalized and no other significant gender differences were found. In conclusion, femoral neck length reduces with increasing DDH severity, whilst anteversion tends to increase. Male patients with DDH have significantly less femoral anteversion, which has important implications for osteotomy and arthroplasty surgery in DDH. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Cementless hip arthroplasty and transverse shortening femoral osteotomy with the S-ROM stem for Crowe type IV developmental dysplasia

INTRODUCTION

The aim of this study has been to present outcomes after cementless arthroplasty for developmental dysplasia Crowe type IV of the hip, with transverse subtrochanteric shortening osteotomy and using the S-ROM stem.

METHODS

We evaluated radiographs, functional scores and complications in a consecutive series of 23 patients (28 hips) with high dislocation of the hip. The average age of patients at surgery was 49.9 (range 22-68) years. The operations were performed between 2007 and 2013. Patients were assessed retrospectively-clinically and radiographically during the year 2018.

RESULTS

The mean follow-up period was 94 (range 60-134) months. The average Harris hip score improved from 39.9 to 84.0. The mean leg length discrepancy decreased from 5 cm preoperatively to 1.4 cm at the final follow-up. All acetabular components were implanted into the true acetabulum, and all prostheses were stable at the latest examination. No neurovascular damage was recorded. We have identified specific complications in seven hips (25%) in total: Intraoperative femoral fracture required fixation in four hips; three hips (10.7%) needed revision: Recurrent dislocation, with the need for cup reorientation, occurred in two hips (in one of them, this was followed by the subsequent need for resection of heterotopic ossification); there was one aseptic stem loosening with the need of one-stage revision. All the osteotomies healed within 8 months.

CONCLUSION

Hip arthroplasty with transverse shortening femoral osteotomy, using S-ROM stem, is an acceptable, but not complication-free treatment method in patients with Crowe type IV developmental hip dysplasia, in the midterm.

Total hip arthroplasty with a monoblock conical stem and subtrochanteric transverse shortening osteotomy in Crowe type IV dysplastic hips

PURPOSE

This series assessed the clinical and radiographic outcomes of total hip arthroplasty (THA) with femoral shortening osteotomy for the management of patients with Crowe type IV hip dysplasia.

METHODS

Only patients with Crowe type IV hip dysplasia who underwent primary THA combined with a subtrochanteric transverse osteotomy with an uncemented monoblock conical stem were included. The clinical and radiographic evaluations were performed before and immediately after surgery, and at last follow-up. The hip function was assessed with the Harris Hip Score (HHS).

RESULTS

Seventy-four patients (102 hips) with a mean age of 53.9 (range, 20-83) were evaluated at an average follow-up of 11.3 years (range, 5-25). Stem revision occurred in two (1.9%) cases, with a survivorship of 95.9% (95%IC, 91.9-99.9%) at ten years. The average HHS increased from 44 (range, 15-78) pre-operatively to 90.3 (range, 62-100) at last follow-up (p < 0.001). Osteotomy site non-union and early dislocation were observed in 3.9 and 3.8%, respectively. No cases of nerve palsy were reported.

CONCLUSIONS

THA with a monoblock conical stem associated with subtrochanteric transverse osteotomy provides good long-term survival, clinical and radiographic results. It may be considered an effective management of patients with Crowe IV hip dysplasia.

[A study of total hip arthroplasty with subtrochanteric osteotomy in Crowe type developmental dysplasia of hip]

Objective

To evaluate the effectiveness of total hip arthroplasty (THA) combined with subtrochanteric osteotomy in the treatment of Crowe type Ⅳdevelopmental dysplasia of the hip (DDH).

Methods

Between April 2008 and June 2016, 71 patients with unilateral Crowe type Ⅳ DDH were treated with THA. Of 71 cases, 44 were performed with subtrochanteric osteotomy (osteotomy group) and 27 were performed without subtrochanteric osteotomy (non-osteotomy group). There was no significant difference in gender, age, body mass, height, body mass index, affected side, and preoperative Harris score between 2 groups ( P>0.05). The complications were recorded and the effectiveness was assessed by Harris score. Besides, the femoral dislocation height and the settling depth of sleeve were measured in the pelvic anteroposterior X-ray film pre- and post-operatively.

Results

Osteotomy group was followed up 12-90 months (mean. 34.77 months), and non-osteotomy group was followed up 12-79 months (mean, 34.33 months). There was no significant difference in follow-up time between 2 groups ( t=-0.088, P=0.930). There was 11 cases of intraoperative or postoperative complications in osteotomy group, and 3 cases of postoperative complications in non-osteotomy group. Among the osteotomy group, 1 case had nonunion due to infection and received revision after 20 months. No loosening or dislocation of the implant occurred in both 2 groups. Significant differences were found in femoral dislocation height and settling depth of sleeve between 2 groups ( t=-8.452, P=0.000; t=6.783, P=0.000). Moreover，the osteotomy length was not correlated with the settling depth of sleeve ( r=-0.038, P=0.806). At last follow-up, there was no significant difference in Harris score between 2 groups ( t=-1.160, P=0.254).

Conclusion

THA combined with subtrochanteric osteotomy can provide a favorable outcome for treating Crowe type Ⅳ DDH. Furthermore, patients with higher femoral dislocation and severely narrow femoral proximal canals are prone to be peformed with subtrochanteric osteotomy.

The radiological research for pelvis asymmetry of unilateral developmental dysplasia of the hip in adult

Objectives

To investigate whether adult patients with unilateral developmental dysplasia of the hip (UDDH) have pelvic asymmetry and what correlation existing between them.

Methods

A total of 100 adult patients with UDDH were enrolled in the retrospective observational study in Shanghai Jiaotong University Affiliated Sixth People’s Hospital, Shanghai, China, between January 2012 and February 2014. The anteroposterior pelvic radiographs were reviewed and the pelvic heights and ischium heights were measured and compared between the affected and non-affected sides to find out the relationship between the pelvic morphology and hip dysplasia.

Results

The pelvic heights demonstrated significant differences between the non-affected side and the affected side in patients with Crowe type II-IV UDDH (p<0.05), but not in patients with Crowe type I UDDH (p=0.09). There were significant differences in the bilateral ischium heights in patients with Crowe type III and IV UDDH (p<0.05), but not in patients with Crowe type I and II UDDH (p=0.78, p=0.055). In addition, the degree of hip dysplasia was positively associated with the degrees of asymmetry of pelvis (r=0.78, p<0.001) and ischium (r=0.72, p<0.001) in UDDH patients.

Conclusion

The pelvic asymmetry exists in adult patients with UDDH. In addition, the degree of asymmetry has correlation with the degree of hip dysplasia. We recommend that it should be taken more cautions to use teardrops and ischial tuberosity as anatomy landmarks to balance leg-length discrepancy for unilateral DDH patients in preoperative planning and total hip arthroplasty.