Total hip arthroplasty requiring subtrochanteric osteotomy for developmental hip dysplasia: 5- to 14-year results

Use of a Conical Fluted Femoral Stem Eliminates the Need for Fixation in Patients Who Have Crowe Type 3 or 4 Coxarthrosis Undergoing Subtrochanteric Osteotomy

BACKGROUND

This study aimed to analyze the clinical, functional, and radiographic outcomes of patients who had Crowe type 3 or 4 developmental dysplasia of the hip (DDH) undergoing cementless total hip arthroplasty (THA) using a conical fluted femoral stem in combination with a transverse subtrochanteric femoral shortening osteotomy without internal fixation.

METHODS

This retrospective study included the records and radiological data of 114 patients who had Crowe type 3 or 4 DDH who underwent subtrochanteric femoral osteotomy and cementless THA at our institution between 2015 and 2022. The mean age was 46 years (range, 28 to 80), comprising 76 women and 38 men. The mean follow-up duration was 55 months (range, 25 to 85). Patients underwent clinical and radiological evaluations at two, four, eight, 12, and 24 weeks postoperatively and were called for a final evaluation. Radiographic bone union, Harris Hip Score (HHS), true limb-length discrepancy, and Trendelenburg sign were assessed.

RESULTS

A total of 112 hips (98.2%) achieved union at the osteotomy site, with a mean healing time of 5.4 months. The mean preoperative HHS was 50 (range, 42 to 61), which improved significantly to 86 (range, 75 to 98) postoperatively (P < 0.001). The mean preoperative limb-length discrepancy was 3.8 cm (range, two to 5.2), which was reduced to 1.1 cm (range, zero to 1.9) postoperatively (P < 0.001). There were no revisions or component exchanges that were required during the follow-up period, and no patients experienced severe limping postoperatively.

CONCLUSION

The use of a conical fluted femoral stem in patients who had Crowe type 3 or 4 DDH undergoing subtrochanteric femoral osteotomy provides stable fixation and excellent functional outcomes while eliminating the need for additional internal fixation.

Long-term clinical comparison of three different femoral stems in Total Hip Arthroplasty with femoral shortening in patients with high-riding hips

BACKGROUND

Developmental hip dysplasia is a common cause of hip arthrosis in young adults, necessitating total hip arthroplasty (THA) for improved function and pain relief. In cases of high-riding hips, transverse femoral shortening osteotomy is often required to facilitate reduction and prevent neurovascular complications. However, the choice of femoral stem in such cases remains controversial due to variations in design and osteoconductive properties. This study aimed to compare the clinical and radiological outcomes of three different femoral stems used in THA with transverse femoral shortening osteotomy.

METHODS

A retrospective cohort study was conducted on 107 patients who underwent THA with transverse femoral shortening osteotomy between 2004 and 2014. Patients were divided into three groups based on the femoral stem used: Group 1 (Summit Tapered Stem (Depuy®) (n = 39), Group 2 (SL-PLUS Rectangular Stem (Smith & Nephew®) (n = 31), and Group 3 (Wagner Cone Prosthesis (Zimmer®) (n = 37). Clinical outcomes were assessed using the Harris Hip Score (HHS), and radiological evaluations included osteointegration and union rates. One-way ANOVA was used to compare continuous variables among groups, and post-hoc Tukey's HSD test was applied for pairwise comparisons. Kaplan-Meier survival analysis was performed to evaluate implant survivorship.

RESULTS

The mean preoperative HHS significantly improved from 42.7 ± 6.7 to 84.6 ± 11.5 postoperatively (p < 0.001). Group 3 had significantly higher final HHS compared to Group 1 (p = 0.0002), while no significant differences were observed between Group 1 and Group 2 (p = 0.1947) or Group 2 and Group 3 (p = 0.0723). The overall 10-year survival rate was 87.8%, with Group 3 demonstrating the highest survivorship (91%) and Group 2 the lowest (83%). Intraoperative femoral fissure or fracture rates were significantly higher in Group 1 compared to Group 3 (p = 0.0006), and with a significantly increased need for additional plating in Group 1 (p = 0.0031).

CONCLUSIONS

This study suggests that cylindrical fully porous-coated femoral stems (Wagner Cone Prosthesis) provide better clinical outcomes, fewer intraoperative complications, and higher long-term survival rates compared to tapered and rectangular stems in THA with femoral shortening osteotomy. These findings highlight the importance of implant selection in optimizing patient outcomes.

CLINICAL TRIAL NUMBER

Not applicable.

Measure Subtrochanteric Osteotomy in Unilateral Crowe-IV Dysplasia-Surgical Technique

OBJECTIVE

Determining the optimal osteotomy length for patients with unilateral Crowe-IV developmental dysplasia of the hip undergoing subtrochanteric osteotomy remains challenging due to the significant variability in pelvic and spinal alignment. Incorrect osteotomy length, compounded by pelvic or spinal tilt, can adversely affect postoperative gait and long-term outcomes. Therefore, this study could introduce a method to calculate the osteotomy length for patients with unilateral Crowe-IV developmental dysplasia of the hip, correcting spinal and pelvic tilt, and improving patient gait.

METHODS

This is a retrospective study that included 28 patients with unilateral Crowe-IV developmental dysplasia of the hip collected from June 2019 to June 2020, who underwent total hip arthroplasty with measured subtrochanteric osteotomy technique. The average follow-up period was 4.3 years (last follow-up). Harris scores, pelvic tilt angles represented by iliac obliquity angle (IO) and sacral obliquity angle (SO), and postoperative complications were recorded. Statistical analysis was performed using independent sample t-tests for normally distributed data and the Mann-Whitney U test for non-normally distributed data.

RESULTS

Postoperatively, pelvic tilt angles improved significantly. The comparison of preoperative and postoperative 3-month IO angles (8.77° ± 3.31° vs. 5.28° ± 2.29°, p = 0.00), and postoperative 3-month and last follow-up (5.28° ± 2.29° vs. 2.88° ± 1.39°, p = 0.00) showed statistically significant differences. Similarly, the comparison of preoperative and postoperative 3-month SO angles (9.56° ± 3.1° vs. 5.81° ± 2.78°, p = 0.00), and postoperative 3-month and last follow-up (5.81 °± 2.78° vs. 3.59° ± 1.72°, p = 0.00) showed statistically significant differences. Harris scores significantly improved from preoperative to 1-year postoperative (47.35 ± 12.32 vs. 80.5 ± 7.81, p = 0.00), and from 1-year postoperative to last follow-up (80.5 ± 7.81 vs. 90.78 ± 2.86, p = 0.00) with statistical significance. There were no significant differences in adverse event rates between the two groups.

CONCLUSION

Total hip arthroplasty combined with measurement subtrochanteric osteotomy technique improves pelvic tilt and Harris scores in Crowe-IV developmental dysplasia patients. This technique may serve as a guideline for determining resection length.

Similar Outcomes between Monoblock and Modular Femoral Stems in Total Hip Arthroplasty with Shortening Osteotomy for Dysplastic Hips at Five Years: A Systematic Review with Meta-analysis

We aimed to examine the outcomes of arthritic congenital dislocation of hip in adults after subtrochanteric shortening derotation osteotomy (SSDO) with cementless hip arthroplasty at a minimum follow-up period of five years. Bibliographic databases were searched and isolated studies were divided into three groups (1, 2, and 3) based on the femoral stem type (modular, monoblock, or mixed). We pooled 931 hips/737 patients from 20 studies. The mean difference in the Harris hip score (HHS) before and after the operation was 47.55 (95% confidence interval [CI] 43.16, 51.94). On subgroup analysis the mean differences of 46.59 (95% CI 41.67, 51.51), 48.24 (95% CI 41.37, 55.11), and 47.30 (95% CI 43.85, 50.75), respectively in HHS were noted in groups 1, 2, and 3. The incidence of uncontrolled proximal femur fractures was comparable at 7.9% and 4.2% in groups 1 and 2; however, it was 0% and 16.6% for controlled fractures. The incidences of nonunion, dislocation, nerve paralysis, heterotopic ossification and revision due to any cause were 0.3%, 6.5%, 1.7%, 2.1%, and 7.9% for group 1 and 1.9%, 4.3%, 1.6%, 5.6%, and 7.4% for group 2. Similar improvements in functional outcome for both monoblock and modular stems can be expected. An increased incidence of controlled proximal femur fractures was observed with use of modular stems. The nonunion at the SSDO site was sporadic.

Rectangular femoral stems can successfully accommodate the medullary canal in patients with severe hip dysplasia operated on with total hip arthroplasty and a shortening osteotomy: A morphometric study

The current study aimed to objectively evaluate the fit of a rectangular, tapered stem to the severely dysplastic hips on the basis of the proximal femoral anatomy and the dimensional properties of the stem. It was hypothesized that the stem size planned with accordance to the diaphyseal canal width alone can accommodate the distal femur successfully with no sizing mismatch. Forty-six patients (53 hips) suffering from secondary osteoarthritis due to hip dysplasia scheduled for total hip arthroplasty (THA) with a subtrochanteric transverse shortening osteotomy were included. All hips were Crowe type 4. All patients underwent preoperative computed tomography imaging. Height of femoral head center (HCH) was determined. Medullary canal diameter measurements at different levels were made. These were made at a level (1) 35% of HCH above the lesser trochanter (DT +35), (2) 70% of HCH below the lesser trochanter (DT -70), and (3) at the level of isthmus (Di). Medullary canal flare indices were calculated from the individual parameter ratios. Similar measurements were carried out for the different sizes of the femoral stem. The mean DT +35 was 41.9 ± 6.4 mm, the mean DT-70 was 17.3 ± 2.2 mm, and the mean Di was 12.8 ± 1.9 mm. In all femurs, the width of the isthmus was wider than that of the corresponding femoral stem isthmus. The femoral stem sizes established with respect to the diaphyseal width of the femur were all compatible with the isthmus width of the femur. Tapered and rectangular stems can accommodate the proximal femur above and below the osteotomy level in Crowe type IV hip dyplasia patients, thereby constituting a viable option as the femoral stem in this patient group with technically demanding difficulties.

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.

Primary Staged Bilateral Total Hip Arthroplasty in a Patient With Short Stature and Hartofilakidis Type I Developmental Dysplasia of the Hip

Syndromes associated with osteochondrodysplasia, short stature, and DDH are rarely reported in the literature. Total hip arthroplasty (THA) in such cases is a complex procedure with a high rate of complications and difficulties. In this case report, we describe the staged bilateral complex primary THA of a patient with the rare occurrence of a syndrome involving osteochondrodysplasia and DDH, highlighting the surgical challenges and importance of the right prosthesis selection.

Total hip arthroplasty associated with transverse subtrochanteric shortening osteotomy and conical stem fixation in Crowe type IV hip dysplasia

PURPOSE

Total hip arthroplasty (THA) in high-dislocated hip dysplasia is a surgical challenge, presenting difficulties in the biomechanical reconstruction of the hip. The purpose of the present study is to analyze clinical and radiological outcomes of a series of patients with Crowe type IV hip dysplasia who underwent a THA with transverse subtrochanteric shortening osteotomy and conical stem fixation in our Hip surgery unit.

METHODS

This non-interventional retrospective study included all patients diagnosed with Crowe type IV hip dysplasia who underwent a THA using a subtrochanteric shortening osteotomy and uncemented conical stem fixation between January 1, 2008, and December 31, 2015. Demographic, clinical and radiologic data were analyzed, including Harris Hip Score and Oxford Hip Score.

RESULTS

Seventeen hips in 13 patients were included in the final analysis. All patients were women and mean age was 39 years (range 35-45). Mean follow-up was 5.6 years (range 1-8). Average length of the osteotomy was 3.4 cm (range 3-4.5) and mean lowering of the center of rotation was 5.67 cm (range 3.8-9.1). Mean time for bone union was 5.5 months. No nerve palsy or non-union was detected at the end of follow-up period.

CONCLUSION

The use of cementless conical stem fixation associated with a transverse subtrochanteric shortening osteotomy for treating Crowe type IV hip dysplasia permits to correct the rotational alterations of the femur and provides good stability of the osteotomy, with very low risk of nerve palsy and non-union rates.

Acetabular Diameter Assessment and Three-Dimensional Simulation for Acetabular Reconstruction in Dysplastic Hips

BACKGROUND

This study aimed to investigate the relationship between acetabular width, three-dimensional (3D) simulation, and surgical results in total hip arthroplasty patients who have developmental dysplasia of the hip (DDH).

METHODS

This retrospective study included 216 DDH cases. Inner and outer acetabular width (OAW) was measured at the plane passing through the center of acetabular fossa. 3D simulation and 2D standard templating were performed. The actual cup size and the use of augments during surgery were recorded. Association among the indices and their distribution in different types of DDH were analyzed.

RESULTS

A difference of 13 to 14 millimeters (mm) was found between the inner acetabular width and actual cup size used in type II, III, and IV cases, while the difference was 0.2 to 3.6 mm for OAW. The accuracy of 2D templating and 3D simulation in predicting cup size was comparable in Crowe type I (86.5 versus 76%, P = .075), type II (72.7 versus 51.5%, P = .127), and type III (93.3 versus 66.7%, P = .169). The 3D simulation was significantly more accurate in Crowe type IV (89.1% versus 60.9%, P = .001). Augments and bone grafts were significantly more commonly used in type II (25%) than in the other types (0 to 6.5%).

CONCLUSION

OAW more accurately predicted actual cup size than inner acetabular width. The supero-lateral acetabular bone defects in type II cases require additional attention. Compared with 2D templating, 3D simulation is more accurate in predicting actual cup size in dysplastic hips with severe deformity and may be recommended in these selected cases, especially for Crowe IV patients.

Direct anterior versus posteriorlateral approachs for clinical outcomes after total hip arthroplasty in the treatment of severe DDH

BACKGROUND

The total hip arthroplasty (THA) has gained popularity in in the treatment of severe developmental dysplasia of the hip (DDH). the posterior lateral approach (PLA) has good clinical efficacy and has been confirmed by the majority clinicians. Nevertheless, controversy exists regarding longer-term benefits of the direct anterior approach (DAA). The objective of this study was to investigate the clinical efficacy and placement of S-ROM prosthesis in the treatment of severe DDH by The total hip arthroplasty (THA) with different surgical approaches.

METHODS

A retrospective analysis was performed on 42 patients with severe DDH admitted to our hospital from August 2015 to February 2022, who were treated with S-ROM prosthesis for total hip arthroplasty and subtrochanteric osteotomy of the femur. They were divided into DAA group and PLA group according to different surgical approaches. Perioperative indicators and imaging data were collected.

RESULTS

The surgery time, intraoperative blood loss, and creatine kinase difference in DAA group and PLA group was without a statistically significant difference (P > 0.05). The postoperative length of hospitalization was shorter in the DAA group than in the PLA group (6.50 ± 3.15 vs 9.18 ± 4.93, P = 0.045). The acetabular abduction angles、the acetabular anteversion angles, the safe area ratio, The difference of femoral eccentricity, and the vertical difference of rotation center in DAA group and PLA group, there was no statistical significance (P > 0.05). Statistically significant differences were detected the horizontal difference of rotation center (P = 0.044).

CONCLUSIONS

Total hip arthroplasty with S-ROM prosthesis is a feasible procedure for severe dysplastic DDH. The clinical efficacy and prosthesis placement parameters of DAA approach are advantage to those of PLA approach.

Total Hip Arthroplasty With Subtrochanteric Osteotomy for Developmental Hip Dysplasia: A Long-term Follow-up Study

Background

Total hip arthroplasty (THA) for developmental hip dysplasia (DDH) often requires a subtrochanteric shortening derotational osteotomy (SDO) to limit leg lengthening, mitigate risk of peripheral nerve palsy, and reduce excessive femoral anteversion. Few studies exist detailing long-term clinical outcomes and survivorship. The aim of this study is to analyze the long-term outcomes and survivorship of an SDO-THA cohort.

Methods

We retrospectively reviewed all patients who underwent cementless THA with femoral osteotomy due to Crowe I-IV DDH between 1991 and 2001. Primary outcome measures included revision surgery for any reason and functional outcome measures using modified Harris Hip scores. Secondary outcome measures included mode of implant failure and radiographic assessment for osteotomy union, polyethylene wear, osteolysis, and implant loosening.

Results

Our review resulted in 24 SDO-THA cases in 20 patients with a mean follow-up of 19 years (range, 8-27 years). Overall survivorship was 67%. All 8 failures were treated with acetabular revision at a mean time to revision of 11 years (range, 1-25 years). Of the failures, there were 5 cases due to polyethylene wear (62.5%), 2 cases due to acetabular loosening (25%), and 1 case due to recurrent instability (12.5%). The mean postoperative modified Harris Hip score was 76 (range, 52-91) with long-term improvement of 43 points maintained (P < .001).

Conclusions

THA with SDO can produce durable long-term outcomes for the patient with DDH. It is important to consider some common reasons for revision, namely polyethylene wear and osteolysis, acetabular loosening, and recurrent acetabular dislocations.

Total Hip Arthroplasty With the Wagner Cone Femoral Stem in Patients With Crowe IV Developmental Dysplasia of the Hip: A Retrospective Study

BACKGROUND

The aim of this study is to assess treatment of Crowe type IV hip dysplasia with the Wagner cone femoral stem combined with transverse subtrochanteric shortening osteotomy and augmenting the osteotomy site using the intercalary segment as a strut autograft.

METHODS

One hundred twenty-seven hips of 91 patients diagnosed with Crowe type IV hip dysplasia and treated with total hip arthroplasty using the Wagner cone stem combined with transverse subtrochanteric shortening osteotomy were retrospectively evaluated by clinical and radiographic outcomes as well as complications.

RESULTS

The mean follow-up was 8.4 years. The Harris Hip Score and the Western Ontario and McMaster University Osteoarthritis Index scores were significantly improved postoperatively (P = .000). Intraoperative femoral cracks were observed in 70 hips (55.1%) and all femurs healed smoothly. Femoral cracks did not have a significant effect on clinical outcomes, except for heterotopic ossifications (P = .032). The probability of 10-year survivorship of the components free of revision for any reasons as end point was 94.5%; when only the femoral components were considered the survivorship was of 96.9%.

CONCLUSION

Transverse subtrochanteric shortening and augmenting the osteotomy site using the intercalary segment of bone resected from the shortened femur with the Wagner cone stem is an effective and reliable technique in the management of total hip arthroplasty in Crowe type IV hip dysplasia. Stable and firm placing of the femoral component which leads to an increased frequency of intraoperative femoral cracks does not have an unfavorable effect on clinical and radiological outcomes.

[Semi-automated measurement and analysis of three-dimensional acetabular orientation in asymptomatic population and patients of developmental dysplasia of the hip]

OBJECTIVE

To evaluate the three-dimensional acetabular orientation in asymptomatic population and patients of developmental dysplasia of the hip (DDH) using a semi-automated measurement software, which provides data for the differential diagnosis, surgical planning, surgical instrument design, and postoperative evaluation of hip related diseases.

METHODS

Eighty-four cases of CT data in asymptomatic population (asymptomatic group) and 47 cases of CT data in DDH patients (DDH group) were collected. There was no significant difference in gender and age (including age of male and female subgroups) between the two groups ( P<0.05). MaxTHA, a semi-automatic measurement software, was used to measure acetabular inclination and anteversion, including operative inclination (OI), radiographic inclination (RI), anatomic inclination (AI), operative anteversion (OA), radiographic anteversion (RA), and anatomic anteversion (AA). Comparisons were made between the two populations, between different Crowe classification subgroups, between different gender subgroups, and between left and right sides of acetabula.

RESULTS

The comparison between asymptomatic group, healthy side of DDH group, and affected side of DDH group showed that there was no significant difference in acetabular orientation between asymptomatic group and healthy side of DDH group ( P>0.05). The OI, RI, and AI of affected side of DDH group were significantly higher than those in healthy side of DDH group and asymptomatic group, and AA was significantly lower than that in healthy side of DDH group and asymptomatic group ( P<0.05). The comparison between the normal acetabula and DDH acetabula with different Crowe classifications showed that there was no significant difference in the acetabulum orientation between Crowe Ⅰ group and the normal group ( P>0.05). The OI, RI, and AI of Crowe Ⅱ, Ⅲ, and Ⅳ groups were significantly higher than those of normal group ( P<0.05), the OI of Crowe Ⅲ group, RI and AI of Crowe Ⅳ group were significantly higher than those of Crowe Ⅰ group ( P<0.05), the AI of Crowe Ⅳ group was significantly higher than that of Crowe Ⅱ group ( P<0.05), and the OA, RA, and AA of Crowe Ⅲ group were significantly lower than other subgroups ( P<0.05) except Crowe Ⅰ group. The OA, RA, and AA in asymptomatic female group, and the OA and AI in DDH female group were significantly higher than those in all male groups ( P<0.05). The OI, RI, AI, and OA of the right acetabula in asymptomatic male group, and the RI and AI of the right acetabula in asymptomatic female group were significantly higher than those on the left side ( P<0.05).

CONCLUSION

There were significant differences in acetabular orientation between asymptomatic and DDH populations, inter-group differences among Crowe classification subgroups, inter-gender differences among subgroups, and bilateral differences among asymptomatic individuals.

Long-Term Results of Total Hip Arthroplasty with Step-Cut Osteotomy in Crowe Type IV Dysplastic Hips

OBJECTIVE

The purpose of this study was to evaluate the long-term results of sub-trochanteric step-cut shortening osteotomy (SSCO) used in the total hip arthroplasty (THA) procedure for treatment of Crowe type IV dysplastic hips.

MATERIALS AND METHODS

Crowe type IV dysplastic 35 hips of 31 patients were treated with cementless THA. Patients were followed up meanly 9.2 years (range 4-18). SSCO was applied to all hips to reduce the femoral head into the true acetabulum. Autologous bone grafts which were obtained by shortening the femur and cable cerclage wires were used for fixing the osteotomy site. The results were evaluated clinically and radiologically. In clinical evaluation, Harris hip score (HHS) and d'Aubigne hip evaluation criteria were used.

RESULTS

The mean HHS increased from 40.6 to 92.5. Merle d'Aubigne hip evaluation score was increased on average from 1.76 to 5.8 in terms of pain and from 2.9 to 5.5 in terms of range of motion. In 9 hips (25.7%), medialization was achieved by creating a controlled fracture in the acetabulum. The hip rotation center was lowered by an average of 5.7 cm. The average leg lengthening was 3.4 cm. No more than 4 cm lengthening was made. Dislocation did not develop in any of the patients.

CONCLUSION

It was concluded that the long-term results were found to be successful in the THA with SSCO in Crowe type IV dysplastic hips, since nerve complications were reduced, leg-lengthening was achieved, and a painless and mobile hip joint could be achieved.

Minimum 10-Year Results of Cementless Ceramic-On-Ceramic Total Hip Arthroplasty Performed With Transverse Subtrochanteric Osteotomy in Crowe Type IV Hips

BACKGROUND

Total hip arthroplasty (THA) performed for developmental dysplasia of the hip is a technically difficult procedure with a high complication rate, especially in the presence of completely dislocated hips. This study aimed to evaluate at least 10 years of follow-up results of cementless, ceramic-on-ceramic (CoC) THA performed with transverse subtrochanteric osteotomy in Crowe type IV hips.

METHODS

We retrospectively reviewed 50 patients' 67 hips that underwent CoC, cementless THA with transverse subtrochanteric osteotomy between 2008 and 2011. Clinical and radiological data of the hips were examined. Clinical results were evaluated using the Harris Hip Score and the Western Ontario and McMaster Universities Osteoarthritis Index.

RESULTS

The mean Harris Hip Score improved from 22.9 ± 9.9 preoperatively to 94.1 ± 8.1 at the final follow-up (P < 0.001). The median Western Ontario and McMaster Universities Osteoarthritis Index score improved from 72 (interquartile range: 17) preoperatively to 2 (interquartile range: 17) postoperatively (P < 0.001). The preoperative mean leg length discrepancy was improved from 4.9 ± 1 cm to 1.5 ± 1 cm in unilateral cases at the last follow-up (P < 0.001). Revision surgery was required because of nonunion in two patients, prosthetic infection in one patient, and aseptic femoral loosening in the other patient. The overall ten-year survival rate was 94% for femoral stems and 98.5% for acetabular components as per Kaplan-Meier survival analysis.

CONCLUSION

Transverse subtrochanteric shortening osteotomy combined with using cementless acetabular and femoral components with a CoC bearing surface promises successful clinical results and high prosthesis survival in the treatment of Crowe IV hips at long-term follow-up.

Comparison of mid-term clinical results between cementless and cemented femoral stems in total hip arthroplasty with femoral shortening osteotomy for Crowe type IV hips

INTRODUCTION

This report is the first study to compare the clinical outcomes between cementless and cemented femoral prostheses in total hip arthroplasty (THA) with subtrochanteric femoral shortening osteotomy for Crowe type IV hips.

MATERIALS AND METHODS

We identified 26 hips in 20 patients who had undergone cemented (n = 13) or cementless (n = 13) THA with subtrochanteric femoral shortening osteotomy for Crowe type IV hips with a minimum follow-up period of 2 years. The mean follow-up period was 60.8 ± 33.9 months (24-120 months). We compared radiological findings, postoperative clinical recoveries, postoperative complications, and implant survival rates.

RESULTS

In both groups, there were no cases of aseptic loosening for the acetabular and femoral implant. In terms of bone union at the osteotomy site, the mean duration was significantly longer in the cemented group (9.8 ± 4.2 months) than in the cementless group (5.0 ± 1.9 months). The clinical hip score in gait and pain at 3 months postoperatively was significantly higher in the cemented group than in the cementless group, while there were no significant changes at other timepoints between two groups. The number of postoperative complications was not significantly different between the two groups. The implant survival rate was 92% in the cementless group and 100% in the cemented group at 5 years postoperatively (P = 0.31).

CONCLUSIONS

The cemented femoral prosthesis is superior to the cementless femoral prosthesis for early clinical recovery, while the duration required to achieve bone union at the osteotomy site is longer in the cemented femoral prostheses. It is possible for surgeons to perform successful hip reconstructions, regardless of the fixation method used for THA with shortening femoral osteotomy.

Modular prosthesis fracture in a patient with developmental dysplasia of the hip: a case report and literature review

BACKGROUND

Modular prosthesis fracture, especially distal femoral fracture, is a rare complication of total hip arthroplasty (THA). However, it is catastrophic, and may have a serious impact on the patients. A distal femoral prosthesis fracture in a patient with developmental dysplasia of the hip (DDH) with nonunion at the subtrochanteric osteotomy site has not yet been reported in any literature. This report presents the first such case, with a purpose of analyzing the causes of modular prosthesis fractures and nonunion of the osteotomy area, so as to provide orthopedic surgeons with experience and lessons.

CASE PRESENTATION

We report the case of a 52-year-old woman with the distal femoral prosthesis fracture after THA and subtrochanteric osteotomy for Crowe type IV DDH. The patient had severe pain in the left thigh and her activities were limited. Plain radiographs revealed fracture of the left distal femoral prosthesis and nonunion in the subtrochanteric osteotomy region of the left femur. After a revision of the THA, the patient's symptoms were resolved.

CONCLUSIONS

A prosthesis fracture combined with nonunion at the subtrochanteric osteotomy site is a rare complication. Modular THA combined with a subtrochanteric osteotomy in the treatment of Crowe type IV DDH should reduce the damage to blood supply and avoid further nonunion of the osteotomy area, which may otherwise lead to modular prosthesis fractures. A detailed preoperative plan and suitable rehabilitation program may help minimize the occurrence of subtrochanteric osteotomy nonunion and reduce complications, including femoral prosthesis fractures, in patients with DDH.

Controlled fracture of the medial wall versus structural autograft with bulk femoral head to increase cup coverage by host bone for total hip arthroplasty in osteoarthritis secondary to developmental dysplasia of the hip: a retrospective cohort study

Background

Many methods have been proposed to increase cup coverage by host bone during primary total hip arthroplasty (THA) in hip osteoarthritis secondary to developmental dysplasia of the hip (DDH). However, there was no study comparing the results of controlled fracture of the medial wall with a structural autograft with a bulk femoral head.

Methods

Sixty-seven hips classified as Crowe II/III were retrospectively included in this cohort study, which consisted of 33 controlled fractures (group A) and 34 structural autografts (group B). The Harris Hip Scores (HHS) were recorded. The radiological assessments were analyzed. Also, complications are assessed. The paired-sample t test was used for data analysis before and after the operation, while the independent sample T test was used for the comparison between the two groups. The Pearson chi-square test or the Fisher exact test was used to analyze the qualitative comparative parameters. Kaplan-Meier was utilized in the analysis of survivorship with the end points as a revision for any component.

Results

All patients were reconstructed acetabulum at the anatomical location. HHS increased greatly for both groups (p = 0.18). No statistic difference was observed for the two groups in postoperative leg-length discrepancy (0.51 ± 0.29 cm for group A and 0.46 ± 0.39 cm for group B, p = 0.64 ), postoperative height of the hip center (2.25 ± 0.42 cm for group A and 2.09 ± 0.31 cm for group B, p = 0.13), and inclination of the cup (39 ± 4° for group A and 38 ± 3° for group B, p = 0.65 ). The rate of cup coverage for group B (94 ± 2%) was better than for group A (91 ± 5%), (p = .009). The rate of cup protrusio was 48 ± 4% for group A. For both groups, no statistical difference was observed in the cup diameter (p > .05), while group A showed less operation time than group B (p < .001). No complications were observed at the latest follow-up.

Conclusion

Controlled fracture of the medial wall to increase cup coverage by host bone at the anatomical location can act as an alternative technique for DDH Crowe II/III with the advantage of shorter operation time and less technically demanding.

One-Stage Total Hip Arthroplasty with Modular S-ROM Stem for Patients with Bilateral Crowe Type IV Developmental Dysplasia

Objective

The aim of the present paper was to evaluate the results of one‐stage total hip arthroplasty (THA) for patients with bilateral Crowe type IV developmental dysplasia of the hip (DDH).

Methods

Data for 58 patients (116 hips) with bilateral Crowe type IV DDH who had one‐stage THA performed by the same surgeon during the period of April 2008 to February 2019 were retrospectively reviewed. The mean age of the patients was 37.3 years; 5 were men and 53 were women. All patients underwent THA through the posterolateral approach using the Pinnacle acetabular cup, a ceramic‐on‐ceramic bearing, and the modular S‐ROM stem. Subtrochanteric shortening osteotomy was performed on 86/116 hips. Intraoperative conditions were recorded. Radiographic and functional outcomes were evaluated, and complications were recorded.

Results

All patients were followed up for an average of 71.3 ± 37.6 months (range, 12–140). The mean operative time was 276.5 ± 57.9 min (range, 175–540). The mean intraoperative blood loss was 933.6 ± 400.8 mL (range, 300–2000). The mean transfusion requirement was 1778 ± 798.0 mL (range, 575–4550). The mean length of hospital stay was 8.6 ± 3.7 days (range, 5–22). At the final follow‐up, no loosening of acetabular and femoral components was observed. No osteolysis and heterotopic ossification occurred. The mean Harris hip scores were improved from 55.4 ± 14.3 preoperatively to 91.3 ± 4.2 postoperatively (P < 0.001) In terms of complications, no perioperative deaths were recorded. Deep vein thrombosis occurred in 1 hip, with no pulmonary embolism. Intraoperative femur fracture occurred in 3 hips, nerve injury in 1 hip, and leg length discrepancy in 1 patient. Postoperative dislocation occurred in 5 hips and nonunion in 1 hip.

Conclusion

Our data demonstrated that one‐stage bilateral THA for bilateral Crowe type IV DDH is feasible and can effectively restore hip function.

Model to Predict Need for Subtrochanteric Shortening Osteotomy During Total Hip Arthroplasty for Crowe Type IV Developmental Dysplasia

Background

Indications for subtrochanteric shortening osteotomy (SSOT) during Crowe type IV developmental dysplasia of the hip (DDH) are unclear. The aim of this retrospective study was to create a model to predict the need for performing SSOT.

Material/Methods

One hundred forty-nine patients (186 hips) with Crowe Type IV DDH who underwent total hip arthroplasty (THA) with S-ROM implants from January 2010 to November 2018 were included in the study. The acetabular components were placed at the true acetabulum and the trial femoral component was inserted. Reduction then was attempted and if it could not be achieved, SSOT was performed. Using multivariable Cox regression analysis, a model was constructed that included age, sex, surgical history, use of a cone- or triangle-shaped sleeve, secondary acetabulum formation, and percentage of dislocation as predictive factors for SSOT.

Results

SSOTs were performed on 140 of 186 hips. Secondary acetabulum formation was present in 27 hips (58.70%) in which SSOT was not performed 7 (5.00%) in which it was performed. Cone-shaped sleeves were used in 17 hips (36.96%) in which SSOT was not performed versus 15 (10.71%) hips in which it was performed. Dislocation occurred in 31.30±5.80% hips in which SSOT was performed versus 24.05±4.39% of those in which it was not performed.

Percentage of dislocation was associated with an increased likelihood of SSOT (odds ratio [OR] 1.24, 95% confidence interval 1.11–1.38), whereas secondary acetabulum formation (OR 0.10, 0.03–0.33) and use of a cone-shaped sleeve (0.18, 0.06–0.53) were associated with decreased likelihood of SSOT. We established a model for prediction of SSOT with a nanogram and the discriminative ability (C statistic) of it was 0.918 (0.79–0.92).

Conclusions

Factors that significantly affect likelihood of performing an SSOT were identified and a model with significant ability to predict the need for SSOT in patients with Crowe Type IV DDH was created.

Management of limb length problems during total hip arthroplasty for patients with developmental dysplasia of the hip

The anatomy of the acetabulum and femur is usually significantly altered in people with developmental dysplasia of the hip and this leads to secondary osteoarthritis of the hip joint. Ideal positioning of implants and reduction of the joint is technically demanding during arthroplasty. Lengthening may result in nerve palsies and therefore procedures may have to be undertaken to shorten the femur. Other complications include dislocation and non-union at the shortening osteotomy site. Thorough preoperative planning and templating is required before surgery to assess the need for shortening. Shortening osteotomies can be performed at the proximal femur, diaphysis or distal femoral levels, with subtrochanteric being the most common level. The procedure should be customised for each patient after extensive planning and detailed counselling.

Relations between the Crowe classification and the 3D femoral head displacement in patients with developmental dysplasia of the hip

Background

The purpose of this study was to investigate the relationship between the three dimensional (3D) femoral head displacement in patients with developmental dysplasia of the hip (DDH) and Crowe classification.

Methods

Retrospectively, CT scans of 60 DDH patients and 55 healthy demography-matched healthy control subjects were analyzed. Using the anterior pelvic plane a pelvic anatomic coordinate system was established. The center coordinates of the femoral heads of both the DDH patients and control subjects were quantified relative to the pelvic coordinate system and were mapped proportionally to a representative normal pelvis for comparison.

Results

In the anteroposterior (AP) direction, the center of the femoral head was significantly more anterior in the DDH patients (type I, II, and III, respectively45.0 ± 5.5, 42.9 ± 7.1, and 43.9 ± 4.6 mm) when compared to the controls (50.0 ± 5.2 mm) (p < 0.001 for all). In the medial-lateral (ML) direction, the center of the femoral head was significantly more lateral in the DDH patients (type I, II, and III =103.5 ± 8.6, 101.5 ± 6.6, 102.1 ± 11.2 mm) when compared to the controls (87.5 ± 5.1 mm) (p < 0.001 for all). In the superior-inferior (SI) direction, the center of the femoral head was significantly more proximal in the DDH patients (type I, II, and III =62.4 ± 7.3, 50.0 ± 6.3, and 43.2 ± 6.6 mm) when compared to the controls (66.0 ± 6.2 mm) (p < 0.001 for all).

Conclusions

The severity of DDH using the Crowe classification was related to the degree of the femoral head displacement in the SI direction, but not in the ML or AP directions. By assessing the 3D femoral head displacement in DDH patients, individualized component positioning might benefit surgical outcome.

The Effect of Graft Positions on the Stability of Total Hip Arthroplasty with Different Types of Subtrochanteric Shortening

Objective  The aim of the present study is to investigate the biomechanical stability of different subtrochanteric osteotomy types and graft positions in cases of dysplastic coxarthrosis that require total hip arthroplasty with shortening osteotomy, as well as to find out the most effective osteotomy type and graft position.

Method  Femur sawbones were used to compare different types of femoral shortening osteotomy (transverse, oblique, and step-cut). Strut grafts, which were prepared at the side of the subtrochanteric shortening osteotomy, were fixed in different positions (anterolateral, mediolateral, and anteroposterior). The fixation of the strut grafts was performed using two steel cables (with 2.0 mm of thickness) with the same strength. The failure values of composite femurs were recorded for axial and rotational loadings.

Results  Biomechanically, there were no statistically significant differences between the types of femoral subtrochanteric shortening osteotomy and the positions of the applied strut graft.

Conclusion  No superiority was observed between the types of femoral subtrochanteric shortening osteotomy regarding stability. Additionally, against stress, similar results were obtained for different strut graft positions. In conclusion, we believe that using the method in which the surgeon is experienced and that is the easiest to apply would be the best choice.

[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.

Current concepts in developmental dysplasia of the hip and Total hip arthroplasty

Developmental dysplasia of the hip (DDH) is a spectrum of pathology that involves dysplasia of both the acetabulum and the femur. If left untreated, it can develop to hip pain and osteoarthritis, which eventually require total hip arthroplasty (THA). A broad array of anatomical abnormalities of the acetabulum and femur, plus the younger age of DDH patients make THA a great challenge. Meticulous operation planning with various options is one of the most important prerequisites of a successful THA. This review presents the current concepts of acetabular and femoral reconstruction in THA for DDH, including high hip center, acetabular bone deficiency, highly porous metal, correction of femoral anteversion, femoral shortening osteotomy, stem selection, among others.

Polyethylene Hip Resurfacing to Treat Arthritis and Severe Acetabular Insufficiency

BACKGROUND

Hip dysplasia is the leading cause of hip arthritis in young adults. These patients often participate in active lifestyles that require a full and stable range of motion.

METHODS

Between 2001 and 2011, 232 consecutive polyethylene resurfacing arthroplasties were performed in 201 patients with advanced arthritis from severe acetabular insufficiency due to dysplasia. All patients had Crowe II or III disease. Their mean age at surgery was 43 years. A 2-piece cementless acetabular resurfacing shell with dome screws and a highly cross-linked polyethylene liner were implanted to provide secure fixation, early weight bearing, and a stable hip. Additional structural bone grafts and/or fixation were not used. A cemented or cementless resurfacing prosthesis was used on the femur.

RESULTS

During a mean follow-up of 10 years, 8 hips (3.5%) were converted to a total hip arthroplasty due to acetabular loosening (1), femoral neck fracture (2), femoral osteonecrosis (2), infection (2), or persistent pain (1), resulting in a mean survival of the resurfacing prostheses of 96% (95% confidence interval 89-98). There were no pending revisions and no dislocations. At 2 years postoperative, Harris Hip Scores improved from a preoperative mean of 55 to 97 and University of California Los Angeles activity scores improved from 5 to 8.

CONCLUSION

Hip resurfacing using a 2-piece polyethylene acetabular component for advanced dysplasia has resulted in excellent function and implant survivorship with a low rate of complications at mid-term follow-up.

[Mid-term effectiveness of total hip arthroplasty with subtrochanteric shortening osteotomy in treatment of Crowe type developmental dysplasia of hip]

Objective

To explore the mid-term effectiveness of total hip arthroplasty (THA) with subtrochanteric shortening osteotomy in treatment of Crowe type Ⅳ developmental dysplasia of the hip (DDH).

Methods

Between September 2009 and March 2014, a total of 49 patients (57 hips) who were diagnosed with Crowe type Ⅳ DDH were treated with THA and subtrochanteric shortening osteotomy. Of the 49 patients, 7 were male and 42 were female with an average age of 44.6 years (range, 20-73 years). The preoperative Harris score was 44.68±3.39 and the preoperative leg length discrepancy was (5.27±0.55) cm.

Results

All incisions healed primarily. All patients were followed up 32-87 months (mean, 52.1 months). At last follow-up, the Harris score was 85.67±2.89 and the leg length discrepancy was (1.12±0.48) cm, showing significant differences when compared with the preoperative values ( t=-69.53, P=0.00; t=42.94, P=0.00). X-ray films showed that bone union of the femoral osteotomy end at 6 months after operation. There was no loosening and subsidence of prosthesis at last follow-up.

Conclusion

The subtrochanteric shortening osteotomy with THA in treatment of Crowe type Ⅳ DDH can obtain satisfactory mid-term effectiveness with low risk of peripheral vascular and nerve traction injuries.

The Acetabular Fossa May Not Be Located at the True Center of the Acetabulum: A Detailed Analysis Using Preoperative CT Images

BACKGROUND

The acetabular fossa is thought to be located in the center of the acetabulum, and acetabular reaming in total hip arthroplasty is conventionally performed in the center of the fossa. However, the actual location of the fossa and the influence that hypoplasia or deformity may have on the position of the fossa are unknown. We hypothesized that the fossa is located in the center of the acetabulum, regardless of hypoplasia or deformity.

METHODS

Fifty patients with normal hips (normal hip group), 50 patients with dysplasia who underwent rotational acetabular osteotomy (dysplastic hip group), and 46 patients with osteoarthritis who underwent total hip arthroplasty (osteoarthritic hip group) were evaluated by computed tomography (CT) imaging. On the horizontal plane that passes through the center of the femoral head, the center line of the acetabulum was defined as the perpendicular bisector of the anterior and posterior rims of the acetabulum. The angle and distance of the center of the acetabular fossa in relation to the center line of the acetabulum were evaluated; furthermore, the center position of the fossa from the anterior margin of the acetabulum was calculated as a ratio relative to acetabular size. A 1-way analysis of variance was performed to compare measurements among the 3 groups.

RESULTS

The center of the acetabular fossa was positioned anteriorly to the center line of the acetabulum in all 3 groups. The mean center angle of the acetabular fossa was 14.0° ± 3.8°, 15.2° ± 5.6°, and 14.9° ± 5.5° in the normal, dysplastic, and osteoarthritic hip groups, respectively (p = 0.33). The mean center distance of the acetabular fossa was 5.6 ± 1.8, 5.8 ± 2.3, and 6.1 ± 2.2 mm, respectively (p = 0.55). The mean center position of the acetabular fossa was 38.8% ± 3.3%, 38.5% ± 4.2%, and 38.3% ± 3.9%, respectively (p = 0.71).

CONCLUSIONS

The center of the acetabular fossa is positioned anteriorly to the center of the acetabulum, and the positioning is affected by neither dysplasia nor osteoarthritis. The preconception that the center of the acetabulum corresponds to the center of the acetabular fossa may risk eccentric reaming, possibly damaging the anterior wall.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Direct Leverage for Reducing the Femoral Head in Total Hip Arthroplasty Without Femoral Shortening Osteotomy for Crowe Type 3 to 4 Dysplasia of the Hip

BACKGROUND

A number of methods for reduction in high hip dislocation in total hip arthroplasty (THA) are time-consuming and laborious, and require great surgical skills. This study aimed to introduce a new reduction technique to achieve rapid, safe, and easy reduction in high hip dislocation.

METHODS

We retrospectively reviewed 74 THA patients (82 hips; 44 women, 30 men) with severe hip dysplasia who underwent direct leverage using a Hohmann retractor into the anatomical acetabulum without femoral shortening osteotomy between September 2007 and January 2014. Forty-nine hips were classified as Crowe III and 33 hips were classified as Crowe IV. The mean follow-up period was 5.1 years (range 2-8).

RESULTS

Mean Harris Hip Score increased from 42.1 (range 24-71) before surgery to 89.9 (range 76-100) at final follow-up examination. The legs were lengthened by a mean of 3.0 cm (range 1.1-5.5) and 2.5 cm (range 1.1-3.5) in Crowe III hips and 3.6 cm (range 1.9-5.5) in Crowe IV hips postoperatively. The average leg-length discrepancy at the final follow-up examination was 0.4 cm (standard deviation 0.5 cm). One greater trochanteric fracture occurred during the hip reduction process. One patient developed femoral nerve palsies and recovered completely at 3 weeks postoperatively.

CONCLUSION

Direct leverage using the Hohmann retractor for the reduction in high hip dislocation in THA without femoral shortening osteotomy is simple, safe, and effective.

Mid-term results of total hip replacement with subtrochanteric osteotomy, modular stem, and ceramic surface in Crowe IV hip dysplasia

Background

Total hip athroplasty (THA) in Crowe IV developmental dysplasia of the hip (DDH) presents many challenges for surgeons with regard to acetabular and femoral deformities. The purposes of this study are to (1) report the mid-term results of THA with subtrochanteric transverse osteotomy using S-ROM prosthesis and ceramic-on-ceramic (COC) surface for Crowe type IV DDH; and (2) compare the wear performance between COC and metal-on-polyethylene (MOP) bearing couple.

Methods

Eighty Crowe IV DDH patients (103 hips) treated with cementless THA were retrospectively reviewed. The S-ROM prosthesis was used in all the hips and subtrochanteric osteotomy was performed in 74 hips. COC and MOP bearing surfaces were compared through the evaluation.

Results

At mean follow-up of 65.6 months, the mean Harris hip score improved from 54.2 to 87.7 points; however, Trendelenberg sign positive was confirmed in 20.4% of the hips. Postoperative dislocation occurred in 6 cases and overall 4 hips were revised. With any component revision as endpoint, Kaplan-Meier survival curve showed that 8-year cumulative survival rate in the COC group was 97.2% and 9-year survival rate in the MOP group was 85.9%. The mean linear wear rate for COC and MOP surface was 0.006 and 0.175 mm/y, respectively.

Conclusions

Subtrochanteric osteotomy combined with the modular S-ROM prosthesis and COC surface in Crowe IV DDH has achieved satisfactory mid-term results. However, postoperative dislocation and limp remain major complications. Linear wear rate for MOP surface is high and the long-term prosthesis survival is affected. Ceramic or highly cross-linked polyethylene should be preferred.

Challenges in Total Hip Arthroplasty in the Setting of Developmental Dysplasia of the Hip

BACKGROUND

Developmental dysplasia of the hip (DDH) is a recognized cause of secondary arthritis, which may eventually lead to total hip arthroplasty (THA). An understanding of the common acetabular and femoral morphologic abnormalities will aid the surgeon in preparing for the complexity of the surgical case.

METHODS

We present the challenges associated with acetabular and femoral morphologies that may be present in the dysplastic hip and discuss surgical options to consider when performing THA. In addition, common complications associated with this population are reviewed.

RESULTS

The complexity of THA in the DDH patient is due to a broad range of pathomorphologic changes of the acetabulum and femur, as well as the diverse and often younger age of these patients. As such, THA in the DDH patient may offer a typical primary hip arthroplasty or be a highly complex reconstruction. It is important to be familiar with all the subtleties associated with DDH in the THA population. The surgeon must be prepared for bone deficiency when reconstructing the acetabulum and should place the component low and medial (at the anatomic hip center), and avoid oversizing the acetabular component. Femoral dysplasia is also complex and variable, and the surgeon must be prepared for different stem choices that allow for decoupling of the metaphyseal stem fit from the implanted stem version. In Crowe III and IV dysplasia, femoral derotation/shortening osteotomy may be required. Many complications associated with THA in the DDH patient may be mitigated with careful planning and surgical technique.

CONCLUSION

Performed correctly, THA can yield excellent results in this complex patient population.

Equalisation of leg lengths in total hip arthroplasty for patients with Crowe type-IV developmental dysplasia of the hip: classification and management

AIMS

There is no consensus about the best method of achieving equal leg lengths at total hip arthroplasty (THA) in patients with Crowe type-IV developmental dysplasia of the hip (DDH). We reviewed our experience of a consecutive series of patients who underwent THA for this indication.

PATIENTS AND METHODS

We retrospectively reviewed 78 patients (86 THAs) with Crowe type-IV DDH, including 64 women and 14 men, with a minimum follow-up of two years. The mean age at the time of surgery was 52.2 years (34 to 82). We subdivided Crowe type-IV DDH into two major types according to the number of dislocated hips, and further categorised them into three groups according to the occurrence of pelvic obliquity or spinal curvature. Leg length discrepancy (LLD) and functional scores were analysed.

RESULTS

Type-I included 53 patients with unilateral dislocation, in which 25 (category A) had no pelvic obliquity or spinal deformity, 19 (category B) had pelvic obliquity with a compensated spinal curvature and nine (category C) had pelvic obliquity and decompensated spinal degenerative changes. Type-II included 25 patients with one dislocated and one dysplastic hip, in which there were eight of category A, 15 of category B and two of category C. Pre-operatively, there were significant differences between the anatomical and functional LLD in type-IB (p = 0.005) and -IC (p < 0.001), but not in type-IA, -IIA or -IIB. Post-operatively, bony LLD increased significantly in types-IB, -IC and -IIB, whereas functional LLD decreased significantly in each type except for IIA. The mean functional LLD decreased from 30.7 mm (standard deviation (sd) 18.5) pre-operatively to 6.2 mm (sd 4.4) post-operatively and the mean anatomical LLD improved from 35.8 mm (sd 19.7) pre-operatively to 12.4 mm (sd 8.3) post-operatively.

CONCLUSION

Pelvic and spinal changes are common in patients with Crowe type-IV DDH and need to be taken into consideration when planning THA, in order to obtain equal leg lengths post-operatively. The principal subdivisions of Crowe type-IV DDH which we describe proved effective in achieving equal leg lengths and satisfactory outcomes. Cite this article: Bone Joint J 2017;99-B:872-9.

Tapered stems one-third proximally coated have higher complication rates than cylindrical two-third coated stems in patients with high hip dislocation undergoing total hip arthroplasty with step-cut shortening osteotomy

BACKGROUND

The results of cementless stems in total hip arthroplasty (THA) done because of congenital dislocation with step-cut osteotomy is not well known, particularly the influence of the design and the role of extent of porous coating. Therefore we performed a retrospective study to evaluate the mid to long-term results THA performed with a single type acetabular component and different geometry and fixation type stems with ceramic bearings in the setting of step-cut subtrochanteric osteotomy in high hip dislocated (HHD) patients. We asked if the stem type affect the outcomes in terms of (1) intra and postoperative complication rates (2) radiographic outcomes (3) prosthesis survival in step-cut subtrochanteric shortening osteotomy.

HYPOTHESIS

The type of the stem, whether cylindrical or tapered does not affect the outcome if the femoral canal fit and fill is obtained and the step-cut femoral shortening osteotomy is primarily fixed.

MATERIALS AND METHODS

Forty-five hips in 35 patients with a mean follow up of 10 years (range, 7-14 years) were evaluated. The single type cementless cup was placed at the level of the true acetabulum, a step-cut shortening femoral osteotomy was performed and reconstruction was performed with two different types of tapered stem in twenty-two hips (Synergy™ and Image™ proximally coated, Smith and Nephew, Menphis, TN, USA) and one type of cylindrical stem (Echelon™ with 2/3 coated, Smith and Nephew, Menphis, TN, USA) in twenty-three hips. Harris hip scores (HHS) and a University of California Los Angeles (UCLA) activity scores were calculated for all patients and successive X-rays were evaluated regarding component loosening and osteolysis, along with complications related to bearing, step-cut osteotomy and stem types.

RESULTS

Forty-one hips (91%) had good and excellent clinical outcome according to HHS. The mean UCLA activity scores improved from 3.2±0.6 points (range, 2-4) preoperatively to 6.3 points±0.5 (range, 5-7) at the latest follow-up. The mean femoral shortening was 36±10mm (range, 20-65mm). Four (9%) dislocations were observed. There were five (11%) intra-operative femoral fractures and three (7%) cases of non-union, which were observed in tapered stems. Cylindrical stems had superior neutral alignment primarily. With any stem revision as the end point, cylindrical stems had a higher survival rate (100%) than all tapered stems (82%; 95% confident interval [CI] 77-97%) at ten years. With any revision as the end point, the 10-year survival rate for acetabular component (Reflection-Ceramic Interfit) and for femoral components were 98% (95% CI, 85-99%) and 91% (95% CI, 78-97%), respectively.

CONCLUSIONS

There were more implant related complications in HHD patients undergoing THA when tapered stems with 1/3 proximal coating were used to reconstruct a step cut osteotomized femur, compared to cylindrical stems 2/3 coated.

LEVEL OF EVIDENCE

IV, retrospective study.

Total hip arthroplasty for patients with Crowe type IV developmental dysplasia of the hip: Ten years results

BACKGROUND AND OBJECTIVES

The aim of this study was to determine the rate of union, functional results and complications in patients with Crowe IV developmental dysplasia of the hip (DDH) who underwent cementless total hip arthroplasty (THA) with S-ROM prostheses and subtrochanteric transverse shortening osteotomy.

METHODS

Forty-five patients (52 hips) operated between January 2005 and May 2008, with a mean age of 40.6 years at surgery were followed. The mean follow-up period was 9.8 years. Clinical outcomes, radiographic outcomes and complications were evaluated.

RESULTS

Osteotomy union occurred in 52 of 52 femurs (100%). Mean Harris hip score improved from 33.7 ± 4.7 preoperatively to 81.2 ± 6.3, 90.8 ± 5.3 and 89.8 ± 7.1 at 1, 5 and 10 years postoperatively. Two patients had temporary sciatic nerve paralysis postoperatively, and 2 patients experienced early postoperative dislocation. Two patients complained about mild longer limb length than the non-operated limb at the last follow-up. Three hips showed osteolysis in Gruen zone 1, and 1 hip showed osteolysis in zone 1 and 7. No implants were revised, and no signs of component loosening and migration were observed at the last follow-up visit.

CONCLUSIONS

S-ROM stem combined with transverse subtrochanteric shortening osteotomy in THA for patients with Crowe type IV DDH has good clinical results with small risk of complications.

Long-Term Results of Cementless Total Hip Arthroplasty With Subtrochanteric Shortening Osteotomy in Crowe Type IV Developmental Dysplasia

BACKGROUND

When surgeons reconstruct hips with a high dislocation related to severe developmental dysplasia of the hip (DDH) in total hip arthroplasty (THA), archiving long-term stable implant fixation and improving patient function and satisfaction remain challenging. The purpose of this study was to evaluate the 10-year outcomes of transverse subtrochanteric shortening osteotomy in cementless, modular THA in Crowe type IV-Hartofilakidis type III DDH.

METHODS

We reviewed 62 patients (76 hips) who underwent cementless THA with transverse subtrochanteric shortening osteotomy from 2002-2010. There were 49 women and 13 men with a mean age of 38.8 years, all of whom had Crowe type IV DDH. Mean follow-up period was 10 years. The acetabular cup was implanted in placement of the anatomical hip center in all hips.

RESULTS

The mean Harris Hip Score significantly improved from 38.8 points to 86.1 points. Similarly, modified Merle d'Aubigne and Postel Hip Score, Hip dysfunction and Osteoarthritis Outcome Score, and SF-12 also significantly improved. The mean limb length discrepancy was reduced from 4.3 cm to 1.0 cm. At mean follow-up of 10 years, there were 3 cases of postoperative dislocation, 2 cases of transient nerve palsy, 1 case of nonunion, and 4 cases of intraoperative fracture. Revision surgery was performed in 2 patients due to isolated loosening of acetabular component and femoral stem, respectively.

CONCLUSION

Our data demonstrated that the cementless, modular THA combined with transverse subtrochanteric shortening osteotomy was an effective and reliable technique with high rates of successful fixation of the implants and satisfactory clinical outcomes.

Femoral shortening osteotomy in total hip arthroplasty for severe dysplasia: a comparison of two fixation techniques

PURPOSE

The purpose of this study was to compare two distinct fixation methods for a total hip replacement performed via transverse femoral shortening osteotomy for patients with severe hip dysplasia.

METHODS

In this retrospective study we compared two fixation methods for total hip replacement of 78 hips in 76 patients exhibiting Crowe type IV developmental hip dysplasia (DDH). The hip replacements were performed via a transverse femoral shortening osteotomy and carried out between September 2009 and December 2013. Group I patients underwent fixation of the shortened femoral segment via a cable attached to the osteotomied segment, and group II patients underwent fixation with a plate and screw. We compared the two techniques based on operating time, osteotomy site union time, Harris hip score, hip loosening signs, and overall clinical outcomes.

RESULTS

The mean operating time for groups I and II was determined to be 116.5 ± 12.8 min and 137.7 ± 14 min, respectively (p < 0.05), while the average union time was 113 ± 51 days for group I and 152 ± 37 days for group II (p < 0.05). Fixation of the femur with a cable (group I) is therefore faster and results in more rapid union time when compared to plate osteosynthesis at the osteotomy site (group II). We observed only one non-union in group I compared with three in group II (p = 0.49). Harris hip scores at the final patient follow-up were 82.8 ± 7.8 and 80.8 ± 6.7 for groups I and II, respectively (p = 0.23). Thus, notably no significant differences were observed between the groups with regard to clinical outcomes such as the Harris hip score or loosening of the replacement components.

CONCLUSION

Fixation of the removed femoral segment with a cable provided adequate rotational stability and decreased the operating time, leading to early union at the osteotomy site.

Total hip arthroplasty (S-ROM stem) and subtrochanteric osteotomy for Crowe type IV developmental dysplasia of the hip

BACKGROUND

Developmental dysplasia of the hip (DDH) in adults with severe pain and disability is best treated by total hip arthroplasty (THA). The purpose of this study was to retrospectively evaluate the outcomes of subtrochanteric shortening osteotomy combined with THA using S-ROM stem for those severe patients with a special focus on the effect of two shapes in the subtrochanteric osteotomy ends: Oblique and transverse.

MATERIALS AND METHODS

Twenty one cases with mean age of 43.6 years who met inclusion criteria and were operated between February 2007 and February 2012 were included in the study. Those cases had been divided into two groups (oblique vs. transverse) and all records between the two groups were analyzed.

RESULTS

The Harris hip score significantly improved from 30.6 (range 18-59) preoperatively to 91.2 (range 87-98) postoperatively by the latest followup. Complications including one deep venous thrombosis, one intraoperative fracture of femur and two dislocations occurred while they were addressed properly afterward. The oblique group showed significant advantages in operative time, union time and additional fixation in comparison with the transverse group.

CONCLUSIONS

In the primary THA for the treatment of irreducible DDH, subtrochanteric oblique osteotomy combined with the freely-rotatable S-ROM stem provided favorable short term outcomes by affording both morphological and functional advantages.

Transverse Subtrochanteric Shortening Osteotomy During Cementless Total Hip Arthroplasty in Crowe Type-III or IV Developmental Dysplasia

The purpose of this study was to review the outcomes of transverse subtrochanteric shortening osteotomy during cementless total hip arthroplasty in Crowe Type-III or IV developmental dysplasia. Seventy-three osteotomies were included in our study. Mean follow-up was 61 months. Harris hip score, leg length discrepancy, neurological status, union status of the osteotomy, and femoral component stability were the criteria for evaluation. All complications were noted. The mean Harris hip score improved from 38.6 points to 83.7 points. The mean leg length discrepancy decreased from 56.5 mm to 10.7 at the latest follow-up. The mean union time was 5.2 months. We observed 4 non-unions. Transverse subtrochanteric shortening osteotomy is an effective and reliable method in restoration of a more normal limb.

Total hip arthroplasty with a non-modular conical stem and transverse subtrochanteric osteotomy in treatment of high dislocated hips

Conventional stems may be unsuitable for hypoplastic femurs associated with severe dysplasia, meanwhile, custom-made or modular stems in total hip arthroplasty are often complex and expensive. This series included 21 Crowe type IV dysplastic hips in which a non-modular cementless conical stem was implanted with transverse subtrochanteric femoral osteotomy. Follow up averaged 40months. Twenty hips survived with mean Harris hip score improved from 52 to 90. One hip failed for stem loosening. The average leg lengthening was 3.8cm with transient sciatic nerve palsy occurring in three hips. Femoral offset averaged 3.3cm postoperatively. The non-modular conical stem not only obviated the complexities, high medical cost and potential risk at the neck-stem interface associated with stem modularity, but also simplified surgical technique.

A reduction technique of arthroplasty without subtrochanteric femoral shortening osteotomy for the treatment of developmental high dislocation of hip: a case series of 28 hips

In total hip arthroplasty for the treatment of developmental dysplasia of the hip (DDH) with high hip dislocation, it can be technically challenging to locate the true acetabulum and restore limb length without subtrochantric femoral shortening osteotomy. We explored and described total hip arthroplasty without subtrochanteric femoral shortening osteotomy in 28 hips with Crowe type III and IV dislocation by intravenous injection of rocuronium at 0.9mg/kg 1minute before reduction and hip reduction combined with continuous strong traction of the affected limb with patients in a position with hip and knee flexion. All patients did not show dislocation, prosthesis loosening, and other severe complications. It is thus a safe and feasible reduction technique for arthroplasty of Crowe type III or IV dislocation of DDH.

Total hip arthroplasty with subtrochanteric osteotomy in neglected dysplastic hip

PURPOSE

Total hip arthroplasty (THA) in the presence of developmental dysplasia of the hip (DDH) presents many challenges to the reconstructive surgeon. The complexity of femoral and acetabular anatomy in these cases makes standard reconstruction technically challenging. Restoring the anatomic centre of hip rotation may require femoral osteotomy. The aim of this study was to determine the rate of union, complications and functional results in a series of patients with Crowe IV dysplastic hips who underwent cementless THA and simultaneous subtrochanteric oblique osteotomy.

METHODS

A retrospective study was designed in a series of 13 patients (14 hips) with Crowe IV DDH who underwent cementless THA and simultaneous subtrochanteric oblique osteotomy at a mean age of 37 years. Patients were reviewed clinically and radiographically with a minimum follow-up of two years. Complications were noted. Harris Hip Score (HHS) was recorded pre-operatively and at six and 12 months postoperatively.

RESULTS

Union occurred in 14 of 14 femora (100%). The overall revision rate was 14% (7% femoral, 7% acetabular). No dislocations necessitated further surgery. No patient had intraoperative femoral fracture, sciatic nerve injury, infection or deep venous thrombosis. Mean HHS improved from 42 preoperatively to 79 at 6 months and 86 at 12 months.

CONCLUSION

Combined subtrochanteric femoral osteotomy and cementless THA is technically demanding and proved to be safe and effective in femoral shortening for treatment of Crowe IV DDH.

Comparison of transverse and modified subtrochanteric femoral shortening osteotomy in total hip arthroplasty for developmental dysplasia of hip: a meta-analysis

BACKGROUND

Subtrochanteric femoral shortening osteotomy is a crucial procedure to prevent nerve injury in total hip arthroplasty for severe developmental dysplasia of the hip. Transverse osteotomy was first applied, and other modified methods have also been reported. Each has its own advantages and limitations, but no definitive conclusions regarding differences in outcomes have been reached to date.

METHODS

We therefore performed a comprehensive meta-analysis to compare the outcomes of different approaches. 37 studies (795 hips) were included in the final analysis. Meta-analysis, subgroup analysis and meta-regression were performed.

RESULTS

Meta-analysis and subgroup analysis showed no significant difference between transverse and modified method. This is further confirmed by meta-regression. Method of osteotomy was found to be not associated with nonunion rate (P = 0.472), as well as other post-operative outcomes including nerve palsy (P = 0.240), dislocation (P = 0.735), revision (P = 0.653) and Harris hip score improvement (P = 0.562). In addition, western countries (P = 0.010) and duration of follow-up more than 5 years (P = 0.014) were associated with higher revision rate.

CONCLUSIONS

Transverse osteotomy and modified osteotomy appear to be equivalent in terms of nonunion, safety and efficacy. Transverse osteotomy may be recommended, due to its simplicity and convenience in adjusting the anteversion angle. Well-designed and large-sample-size randomized controlled trials are expected to confirm and update the findings of this analysis.

Subtrochanteric shortening in total hip arthroplasty: biomechanical comparison of four techniques

Safe reduction of the femoral head into the true acetabulum requires a certain amount of femoral shortening in patients with high dislocation of the hip. In subtrochanteric shortening applications, to reduce complications it is necessary to maintain a stable fixation at the osteotomy line. The purpose of this study is to investigate frequently used methods from a biomechanical point of view. Four osteotomy groups were created with composite femurs to investigate subtrochanteric osteotomies; transverse, oblique, z-subtrochanteric and double Chevron. All loading tests were carried out with two implant types both with and without strut graft and cable fixation. No single inherent feature increasing the stability of the investigated osteotomy types was found. Additionally graft application did not have a significant contribution to stability.

The dysplastic hip: not for the shallow surgeon

Total hip replacement for developmental hip dysplasia is challenging. The anatomical deformities on the acetabular and femoral sides are difficult to predict. The Crowe classification is usually used to describe these cases - however, it is not a very helpful tool for pre-operative planning. Small acetabular components, acetabular augments, and modular femoral components should be available for all cases. Regardless of the Crowe classification, the surgeon must be prepared to perform a femoral osteotomy for shortening, or to correct rotation, and/or angulation.

Acetabular configuration and its impact on cup coverage of a subtype of Crowe type 4 DDH with bi-pseudoacetabulum

The purpose of this study was to explore the acetabular configuration of a special subtype of Crowe type 4 DDH and its impact on cup coverage, which was identified with a particular bi-pseudoacetabulum and an inter-pseudoacetabulum spine structure. The altered bone stock and anatomic structures were believed to be a result of lesser trochanter impingement on the pelvis as observed in all hips of this series, which was supported by the radiographic and intraoperative findings. Acetabular characteristics were depicted by means of radiographic assessment and direct observation during surgery. Preoperatively, the horizontal distance to the hip centre was 80.5 mm on average and 52.9 mm for femoral head height with a significant difference compared to the general series of DDH cases. Anterosuperior bony coverage was found 
to be more adequate with a thicker anterior wall. The postoperative hip centre was restored to the true acetabulum to within 23.4 mm vertically and 25.2 mm horizontally, and sufficient cup containment was achieved when the acetabular inclination angle was below 45°. A larger diameter cup (range 46-50 mm) was employed. No structural bone graft was required, and the medial protrusion technique was infrequently required. This subtype of DDH facilitated cup coverage during THA.

Results of total hip arthroplasty differ in subtypes of high dislocation

BACKGROUND

In a previous study, we described two subtypes of high dislocation of the hip depending on the presence (C1) or absence (C2) of a false acetabulum, yet we have already presented the concise followup of total hip arthroplasty (THA) in these patients as a group at a minimum of 15 years.

QUESTIONS/PURPOSES

In this retrospective study, we investigated differences in the results of THA in the C1 and C2 subtypes of high dislocation such as (1) survivorship of the reconstructions; (2) Merle d'Aubigné-Postel clinical scores; (3) leg lengthening and femoral shortening; and (4) site of reattachment and union rate of the greater trochanter.

METHODS

We included 49 hips of the C1 subtype and 30 hips of the C2 subtype operated on from 1976 to 1994. We evaluated survivorship (using reoperation for any reason as the end point) and performed chart and radiographic reviews.

RESULTS

The 15-year survival was 84% (± 10% [95% CI]) for the C1 subtype and 60% (± 17% [95% CI]) for the C2 subtype (p = 0.001). Cox regression analysis, after adjustment for confounding factors, showed also statistically significantly worse survivorship in the C2 subtype (p = 0.021) and, after adjustment for possible predictive factors, found a statistically significant relationship of high dislocation subtype (p = 0.018) and trochanteric union (p = 0.005) with survival of THAs. Pain, function, and mobility scores improved from preoperative to last followup in C1 and C2 groups but they did not differ between C1 and C2 hips. C2 hips were lengthened more (p < 0.001) despite greater amounts of femoral shortening (p = 0.006). Site of reattachment and the risk of greater trochanter nonunion were not different between the groups.

CONCLUSIONS

We found important differences in fundamental parameters after THA in the high-dislocation subtypes, including the risk of revision, which was higher in patients whose hips did not have a false acetabulum. These findings indicate that while reporting THA results in patients with high dislocation, mixing results of the two subtypes may lead to statistical bias.

Double acetabular wall--a misleading point for hip arthroplasty: an anatomical, radiological, clinical study

PURPOSE

Despite the great attention focused on cup positioning in primary total hip arthroplasty (PTHA), it is surprising to find so few studies that have dealt with cup placement. A common thwarting problem for correct cup placement during PTHA is the existence of osteophytes, which obscure the anatomical landmarks. In this study we aimed to evaluate the morphology of acetabular osteophyte formation in patients with osteoarthritis.

METHOD

We evaluated 276 patients with hip complaints, using plain X-rays and CT scans.

RESULTS

Of these patients, 57 underwent surgery. We developed a staging system for central osteophytes in hip osteoarthritis based on the radiographic and anatomical findings of our patients.

CONCLUSION

We recommend routine use of CT scans for patients scheduled for PTHA in order to assess the stage of osteophyte before surgery and, thus, reduce the risk of failure resulting from the interrupted acetabular landmarks.

Cementless total hip arthroplasty with modified oblique femoral shortening osteotomy in Crowe type IV congenital hip dislocation

Midterm results of cementless total hip arthroplasty in patients with Crowe type IV congenital dislocation of the hip were evaluated. A modified oblique subtrochanteric shortening osteotomy was used in all patients. A cylindrical femoral stem was used in all patients to stabilize the osteotomy. Mean follow-up was 82 months in 20 hips of 16 patients. Mean Merle D'Aubigné pain score increased from 2.52 to 5.65 points, function score improved from 4.0 to 5.3 points, and mobility score improved from 3.95 to 5.35. Mean greater trochanter height relative to the estimated hip center was 6.8 ± 2.0 cm preoperatively and -1 ± 0.2 cm postoperatively. Complications were dislocations in 3 patients, which were successfully managed without redislocation and fracture of greater trochanter in 3 patients, which healed uneventfully in 2 but with residual Trendelenburg gait in one. Total hip arthroplasty with modified oblique subtrochanteric shortening osteotomy is an effective technique for the treatment for Crowe type IV hip dislocation.

Cementless total hip replacement for severe developmental dysplasia of the hip: our experience in Crowe's group IV

Total hip replacement in developmental dysplasia of the hip grade IV of Crowe's classification presents some difficulties. In this study, we present our results of the treatment for this pathology, also describing the surgical techniques used and the complication we had. In this paper, 18 total hip replacements in developmental dysplasia of the hip Crowe IV were studied clinically and radiologically before and after surgery, with a mean follow-up of 4.2 years (min: 1 year). The average Harris Hip Score improved from 52 to 89. The average leg lengthening was 36 mm. When a subtrochanteric shortening osteotomy was performed, the healing occurred in all cases, in an average time of 5.3 months. At now, the implant survivorship is 100% (no revision required). The techniques and principles described in this paper allow to achieve good results in this surgery. An accurate preoperative evaluation and the availability of specific materials are also important steps. The subtrochanteric shortening is a safe procedure to avoid neurovascular injuries.

Total hip arthroplasty for Crowe type Ⅳ developmental dysplasia

The purposes of this study were to evaluate the midterm clinical and radiographic results of total hip arthroplasty (THA) in patients with Crowe type IV developmental dysplasia and to evaluate whether low back pain would improve after THA. Eighteen consecutive patients (20 hips) were included in this study. The average age at the time of surgery was 58.5 years. The average follow-up was 10.2 years. The socket was placed at the level of the true acetabulum, and a femoral shortening osteotomy was performed. The average Harris hip score before surgery was improved from 56 to 85 points at the final follow-up. Revision was performed in 4 hips due to loosening of the femoral component in 1 hip and osteolysis in 3 hips. The midterm outcomes of THA in patients with Crowe type IV developmental dysplasia were satisfactory. The severity of low back pain was significantly reduced after THA.