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

Is step-cut shortening osteotomy a better choice than transverse osteotomy for total hip arthroplasty for Crowe type III-IV hip dysplasia?

INTRODUCTION

Total hip arthroplasty for developmental hip dysplasia is a challenging surgery due to anatomic abnormalities. Crowe III and Crowe IV hip dysplasia generally necessitates a subtrochanteric shortening osteotomy. Transverse and step-cut osteotomy are the most common procedures for shortening of femur although there is still no consensus which one is a superior method. The objective of this study was to demonstrate whether transverse or step-cut osteotomy is superior in hips who undergo arthroplasty for high riding hip dysplasia.

HYPOTHESIS

Our hypothesis was that higher rates of union would be achieved in patients with Crowe III-IV hip dysplasia when the step-cut osteotomy was performed compared to transverse osteotomies.

MATERIAL AND METHODS

A total of 99 hips from 90 patients (9 bilateral, 81 unilateral; 79 female, 11 male), each with a minimum follow-up duration of two years, were included in this study. The hips were classified as Crowe III (n=16) or IV (n=83). All hips were implanted cementless. Transverse or step-cut osteotomy was chosen for osteotomy type. The clinical and functional outcomes were assessed using the Harris Hip Score (HHS), limb length discrepancy (LLD), and limping. The complications and management of these were noted. The union rates were compared between osteotomy types.

RESULTS

The mean age at surgery was 48.8 (range, 21-79 years). The follow-up period was 64.3 months in average (range, 24 to 192 months). The mean Harris Hip Score before surgery was 35.6 (range, 18-50), and increased to 88.1 (range, 61-98) points at the most recent follow-up. The preoperative leg length discrepancy (LLD) measured 5.3cm (with a range of 3 to 6.8), while the postoperative LLD reduced to 0.8cm (with a range of 0 to 1.6). There were a total of 38 complications in 35 patients out of 99 cases, resulting in a complication rate of 38.4%. The most frequent complication observed was intraoperative femoral fractures, occurring in 13 cases. Residual limping was seen in 73.7% of all. Step-cut osteotomy was performed in 64 hips (35 CDH stem [Zimmer Biomet, Warsaw, IN, USA], 29 Wagner Cone stem [Zimmer Biomet, Warsaw, IN, USA]) and, transverse in 35 hips (22 CDH, 13 Wagner Cone). Six hips had nonunion problem and all of them were operated with a step-cut osteotomy (z-score: -7.12 and p<0.00001, Mann-Whitney U Test).

CONCLUSION

Transverse osteotomy may be a better option while performing a shortening subtrochanteric level osteotomy for total hip arthroplasty for Crowe III-IV hips.

LEVEL OF EVIDENCE

Level III; observational retrospective cohort study.

Total hip arthroplasty with subtrochanteric femoral shortening osteotomy using a monoblock cylindrical cementless stem for severe developmental hip dysplasia (Crowe type III, IV)

BACKGROUND

Treatment of patients with Crowe type III and IV dislocated hips is challenging because of the hip deformity in these patients. In addition to the usual total hip replacement, shortening and reduction of the femur are often required. We herein report on our surgical technique using a monoblock cylindrical cementless stem and a direct lateral approach.

METHODS

This study included patients with a diagnosis of severe developmental dysplasia of the hip (Crowe types III and IV) who underwent primary total hip arthroplasty at our hospital from August 2019 to January 2022. Eleven hips of seven patients were treated. All patients underwent horizontal osteotomy using a monoblock cylindrical cementless stem and a direct lateral approach. Complications such as dislocation, infection, and implant dropout were evaluated. In addition, the clinical assessment included the hip range of motion at the last observation and hip function based on the Japanese Orthopaedic Association (JOA) hip score and the Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ).

RESULTS

The average operation time was 224 min (range, 194-296 min), and the average bleeding amount was 396.1 g (range, 20-1010 g). The main complications were acetabular implant dislocation, postoperative dislocation, intraoperative arterial injury, intraoperative proximal femoral fracture, subsidence of femoral implant. and postoperative pulmonary infarction, which occurred in one patient each.

CONCLUSION

Total hip arthroplasty for Crowe type III and IV hips is associated with various surgical technical difficulties because of its anatomical characteristics. While patients with severe osteoporosis are contraindicated, the use of a cylindrical monoblock cementless stem and the direct lateral approach makes it possible to simplify the procedure for shortening the femur and increase the indications for surgery.

LEVEL OF EVIDENCE

Therapeutic Level Ⅳ.

Subtrochanteric Shortening Osteotomy Provides Superior Function to Trochanter Slide Osteotomy in THA for Patients With Unilateral Crowe Type IV Dysplasia at a Minimum of 3 Years

BACKGROUND

Performing THA in patients with high-riding developmental dysplasia of the hip (DDH) is associated with serious complications and technical challenges. Various methods of shortening osteotomy are available to facilitate femoral head reduction during THA in patients with high-riding hips; subtrochanteric shortening osteotomy and trochanteric slide osteotomy plus proximal shortening are the most common techniques. However, which approach is superior remains a topic of controversy.

QUESTIONS/PURPOSES

(1) Is there any difference in clinical outcomes (defined as the Harris Hip Score [HHS] and residual limb length discrepancy) at a minimum of 3 years between subtrochanteric shortening osteotomy and trochanteric slide osteotomy in patients with Crowe Type IV DDH who underwent THA? (2) Is there any difference in the risk or type of complications between the two approaches?

METHODS

We performed a retrospective, comparative study of two groups (subtrochanteric shortening osteotomy versus trochanteric slide osteotomy) matched for sex and preoperative HHS at a minimum of 3 years of follow-up. Between 2010 and 2018, we performed 67 THAs in patients with unilateral Crowe Type IV DDH. During that time, we generally used a trochanteric slide osteotomy for THA in all patients with Crowe Type IV hips and performed subtrochanteric shortening osteotomy when a conical stem was not available. A total of 42% (28) had THA with subtrochanteric shortening osteotomy, and 58% (39) had THA with trochanteric slide osteotomy. Of those, 89% (25) and 74% (29), respectively, were accounted for with complete datasets for possible matching at a minimum of 3 years of follow-up. Patients were matched for gender and preoperative HSS (within 10 points), leaving 22 patients in each group (79% of the subtrochanteric shortening osteotomy group and 56% of the trochanteric slide osteotomy group) for evaluation and analysis. Age (42 versus 46 years), gender (female: 73% versus 73%), preoperative HSS (40 versus 40), and preoperative leg length discrepancy (5.9 versus 5.3 cm) were comparable between the two groups (p > 0.05). The trochanteric slide osteotomy group exclusively received Cone Wagner (Zimmer) implants (100%), while Corail (DePuy Synthes) implants (77%) were the most commonly used in the subtrochanteric shortening osteotomy group. HHS at a minimum of 3 years as well as the presence or absence of a limp and Trendelenburg sign, functional leg length discrepancy, nonunion, nerve palsy, and other surgical complications were recorded and compared between the groups based on data drawn from a longitudinally maintained institutional database.

RESULTS

At a mean follow-up of 73 months, improvement in HHS was greater in the subtrochanteric shortening osteotomy group than in the trochanteric slide osteotomy group (48 ± 4 points versus 36 ± 11 points, mean difference 12 points [95% CI 7 to 17 points]; p < 0.001). Although the preoperative leg length discrepancy was similar between the groups, there was a greater postoperative improvement in the subtrochanteric shortening osteotomy group (44 ± 8 mm and 38 ± 8 mm in the subtrochanteric shortening osteotomy and trochanteric slide osteotomy groups, respectively; p = 0.02). The risk of nonunion was higher with a trochanteric slide osteotomy than with a subtrochanteric shortening osteotomy (23% [5 of 22] versus 0% [0 of 22]; p = 0.048). Other complications, including intraoperative periprosthetic fractures, nerve palsy, heterotopic ossification, revision surgery, and dislocation, did not differ between the groups.

CONCLUSION

In patients with Crowe Type IV hips undergoing THA, surgeons might consider subtrochanteric shortening osteotomy rather than trochanteric slide osteotomy to minimize the risk of nonunion and achieve superior hip function. Better correction of leg length discrepancy may also be possible with subtrochanteric shortening osteotomy. The long-term survivorship of hips after these two techniques, as well as the influence of the specific anatomy of the proximal femur on the choice of technique, remain to be explored in future studies.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Subtrochanteric Osteotomy in Direct Anterior Approach Total Hip Arthroplasty for Crowe IV Dysplasia-Surgical Technique and Literature Review

For Crowe IV dysplasia, the clinical efficacy and surgical technique of subtrochanteric osteotomy (SO) within the direct anterior approach total hip arthroplasty (DAA-THA) was a subject of debate. This study aimed to describe the surgical technique and clinical outcomes in 11 cases of SO in DAA-THA and to summarize the relevant literature on this topic. Between June 2016 and June 2023, we retrospectively evaluated patients diagnosed with Crowe IV hip dysplasia at our institution. Criteria identified 11 patients who underwent SO during DAA-THA. Comprehensive data encompassing demographic information, radiological data, prosthetic implant type, and surgical intricacies were collected. In addition, an exhaustive review of existing case series literature was undertaken utilizing the PubMed databases. There were no revisions, deaths, dislocations, or infections. One hip (9.09%) had an intraoperative proximal split fracture, two hips (18.2%) had lower limb deep vein thrombosis, and one hip (9.09%) had symptoms of femoral nerve injury. Radiological data showed improved bilateral femoral offset, leg length discrepancy, and anatomical acetabular. During the mean follow-up of 2.18(1.06-2.46) years, patients demonstrated enhanced functional outcomes, with average changes of 25.2 in the Harris hip score and 47 in the WOMAC score. Reviewing the literature, most studies have favored S-ROM prostheses and transverse osteotomy techniques. Intraoperative fractures were notably frequent, with rates peaking at 25%. Nonunion and nerve injury were secondary common complications. SO via DAA-THA may offer satisfactory clinical and radiographic outcomes, but the literature review underscores the need for heightened awareness of intraoperative fracture risk. Proximal detachment of the vastus intermedius plays a pivotal role in SO exposure through the DAA.

Clinical efficacy of greater trochanter osteotomy with tension wire fixation in total hip arthroplasty for Crowe type IV developmental dysplasia of the hip

OBJECTIVE

The choice of osteotomy in joint replacement surgery for Crowe type IV developmental dysplasia of the hip (DDH) is a challenging and controversial procedure. In this study, we compared the clinical efficacy of a combination of greater trochanter osteotomy and tension wire fixation with that of subtrochanteric osteotomy.

METHODS

We performed 15 primary total hip arthroplasty (THA) procedures between January 2016 and July 2020 on 13 patients with a combination of greater trochanter osteotomy and tension wire fixation (the GTT group) and 12 THA procedures in 11 patients using subtrochanteric osteotomy (the STO group). The mean follow-up was 2.8 years (range 2.2-4.5 years) in the GTT group and 2.6 years (range 2.5-4.3 years) in the STO group. Clinical scores and radiographic results were evaluated during the final follow-up for the 15 hips in the GTT group and 12 hips in the STO group.

RESULTS

Postoperative Harris hip scores, implant position, and the surgery time did not differ between the treatment groups. There were no differences in preoperative leg length discrepancy LLD (P = 0.46) and postoperative LLD (P = 0.56) between the two groups. Bone union occurred within 6 months after surgery in 12 hips in the GTT group (92.3%) and in 9 hips (81.8%) in the STO group. One case in the GTT group and two cases in the STO group had nonunion, and additionally, there was one case of postoperative nerve injury in the STO group, while no symptoms of nerve damage were observed in the GTT group.

CONCLUSION

The GTT method demonstrated many advantages and reliable clinical results for Crowe type IV DDH patients undergoing THA. This is a surgical method that warrants further development and promotion clinically.

Transverse subtrochanteric shortening osteotomy with double tension-band fixation during THA for Crowe III-IV developmental dysplasia: 12-year outcomes

BACKGROUND

When performing total hip arthroplasty in patients with severe developmental dysplasia, shortening the femur facilitates reduction while also preventing sciatic or crural nerve injury and excessive length of the operated limb. No consensus exists about the optimal type of implant and best internal fixation procedure, two parameters that directly govern the risk of the most common intraoperative and postoperative complications (diaphyseal fractures, dislocation, non-union). To minimise these risks, we developed a technique combining a transverse subtrochanteric shortening osteotomy, a long ovoid-profiled, cementless stem anchored in the metaphysis, and double tension-band wiring for internal fixation. The primary objective of this study was to evaluate the outcomes of this technique with emphasis on (i) complications and femoral implant survival, (ii) clinical outcomes (functional scores and lower-limb length inequality [LLLI]), and time to healing.

HYPOTHESIS

Our technique is associated with low rates of intraoperative and postoperative complications.

MATERIAL AND METHODS

This single-centre retrospective cohort study included patients who underwent THA with a transverse subtrochanteric shortening osteotomy and fixation using double tension-band wiring to treat severe (Crowe III or IV) developmental hip dysplasia. The femoral implant was a long, ovoid, cementless stem fully coated with hydroxyapatite. We collected the intraoperative and postoperative complications, survival, LLLI, functional scores (Harris Hip Score [HHS] and Forgotten Joint Score [FJS]), patient satisfaction, and radiographic outcomes.

RESULTS

The study included 31 hips in 25 patients. Two patients (2/31 hips, 6.5%) were lost to follow-up, leaving 29 hips for the analysis of postoperative outcomes. Mean follow-up was 13.7±4.2 years (range, 5.8-18.3 years). The four intraoperative complications (4/31, 12.9%) consisted fracture of the diaphysis (2/31, 6.5%), fracture of the greater trochanter (1/31, 3.2%), and sciatic nerve injury followed by a full recovery (1/29, 3.4%). The 8 (8/29, 27.5%) postoperative complications consisted of dislocation (2/29, 6.9%), stem subsidence (2/29, 6.9%), and non-union (4/29, 13.8%). Femoral implant survival at last follow-up was 87.1% (95% CI, 76.1-99.7). The mean HHS increased from 39.6±12.0 (range, 14-61) before surgery to 81.7±13.2 (range, 48-100) at last follow-up (p<0.01). The FJS at last follow-up indicated that the joint was forgotten in 14/29 (48.2%) cases and caused only acceptable symptoms in 9/29 (31.0%) of cases. Clinically significant (≥ 1cm) LLLI was present in 8/29 (27.6%) patients postoperatively compared to 19/29 (65.5%) preoperatively. The mean LLLI decreased from 20.8±19.7mm (range, 0-60mm) to 5.0±7.3mm (range, 0-30mm). Mean time to healing was 4.3±2.4 months (range, 2-11 months).

CONCLUSION

Regarding these complex procedures, this technique was associated with low rates of intraoperative fractures and early postoperative complications. However, femoral stem survival was shorter than in earlier studies and the non-union rate was high, despite satisfactory functional and clinical outcomes.

LEVEL OF EVIDENCE IV

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.

"Koehlers teardrop is not a reliable landmark for assessing the centre of rotation after Total hip arthroplasty" - a retrospective radiological study

PURPOSE

Various anatomical landmarks have become established in radiography for the assessment of cup positioning after total hip arthroplasty (THA). The most important one is Koehler's teardrop figure (KTF). However, there is a lack of data on the validity of this landmark, which is widely used clinically for assessing the centre of rotation of the hip.

METHOD

A retrospective measurement of the lateral and cranial distance of the KTF to the centre of hip rotation was performed on the basis of 250 X-ray images of patients who had undergone THA. In addition, the dependence of these distances on pelvic tilt was determined in 16 patients by means of virtual X-ray projections based on pelvic CTs.

RESULTS

It was shown that the distance of the KTF from the centre of hip rotation in the horizontal plane is gender-dependent (men: 42.8 ± 6.0 mm vs. women: 37.4 ± 4.7 mm; p < 0.001) and age-dependent (Pearson correlation  - 0.114; p < 0.05). Furthermore, the vertical and horizontal distances are subject to variation depending on height (Pearson correlation 0.14; p < 0.05 and 0.40; p < 0.001, respectively) and weight (Pearson correlation 0.158; p < 0.05). The distance between the KTF and the centre of hip rotation varies slightly depending on pelvic tilt.

CONCLUSION

The KTF is not a sufficiently valid landmark for assessing the centre of rotation after THA. It is influenced by many different disturbance variables. However, it is largely robust against changes in pelvic tilt, so that it can be used as a reference point when comparing different intraindividual radiographs to assess the change in the centre of rotation due to implantation or to detect cup migration.

Implant loosening following THA with S-ROM prosthesis and subtrochanteric osteotomy: Three case reports

Prosthesis loosening after THA is a rather common complication. For DDH patients with Crowe IV, the surgical risk and complexity is significant. THA with S-ROM prosthesis combined with subtrochanteric osteotomy is a common treatment. However, loosening of a modular femoral prosthesis (S-rom) is uncommon in THA and has a very low incidence. With modular prostheses distal prosthesis looseness are rarely reported. Non-union osteotomy is a common complication of subtrochanteric osteotomy. We report three patients with Crowe IV DDH who developed prosthesis loosening following THA with an S-ROM prosthesis and subtrochanteric osteotomy. We addressed the management of these patients and prosthesis loosening as likely underlying causes.

Mid-Term Outcomes of Cemented Stem and Subtrochanteric Shortening Derotational Osteotomy in Total Hip Arthroplasty for Crowe IV Developmental Dysplasia

OBJECTIVE

Performing subtrochanteric osteotomy with cemented components in patients with Crowe IV developmental dysplasia of the hip (DDH) is technically challenging and not widely reported. This study aimed to evaluate the mid-term outcomes of cemented stem total hip arthroplasty (THA) with subtrochanteric femoral shortening and transverse derotational osteotomy in patients with Crowe IV DDH.

METHODS

Data collected from patients with Crowe IV DDH who underwent cemented stem THA with subtrochanteric femoral shortening and transverse derotational osteotomy between 2010 and 2018 were retrospectively evaluated. The cemented Lubinus SP II femoral component and the cementless CombiCup acetabular component were used together in all cases. These data, including Harris hip scores, limb length discrepancy (LLD), severity of limp, Trendelenburg test, bone union, length of the resected femur, limb lengthening, level of the osteotomy site, and length bridging the osteotomy site, as well as complications, were analyzed. A paired Student t-test was used to analyze continuous variables, categorical data were compared using Fisher's exact probability test, and correlation analysis was performed using Spearman's rank correlation coefficient.

RESULTS

Among 14 included patients (10 females and four males), the mean age was 60.4 years (range, 47-73). The mean follow-up period was 49.1 months, and no patient was lost to follow-up. The mean Harris hip score improved from 40.7 to 87.7. The mean LLD decreased from 52 to 12.7 mm. The mean length of the excised femoral segment was 38.4 mm, and the mean length of limb lengthening was 27.1 mm. The mean distance between the osteotomy site and the lesser trochanter was 21.1 mm after surgery. The mean length of the femoral stem bridging the osteotomy site was 97.6 mm. Finally, the mean osteotomy union time was 10.6 months. No statistically significant correlation was found between the osteotomy union time and these factors. No neurological deficits were noted. Delayed union was observed in one patient, and postoperative dislocation was observed in two patients. Cement leakage into the osteotomy gap was observed in one patient, however, no revisions were required, and no signs of loosening or migration were observed.

CONCLUSIONS

Cemented stem THA combined with subtrochanteric femoral shortening and transverse derotational osteotomy is safe and effective in treating patients with Crowe IV DDH. Rather than leading to nonunion, cement leakage may negatively affect bone healing.

The Clinical and Radiological Outcomes of Subtrochanteric Osteotomy in Crowe Type IV Hip Dysplasia: A Comparison of Three Different Stem Designs

AIMS

The purpose of this study was to determine whether there are differences in clinical and radiographic outcomes among three different stem designs for subtrochanteric osteotomy in Crowe type IV developmental dysplasia of the hip (DDH).

METHODS

A retrospective analysis of prospectively collected data was undertaken from a consecutive series of 37 Crowe type IV DDHs treatment of noncemented total hip arthroplasty with chevron subtrochanteric osteotomy in 30 patients. Patients are divided into three groups, including Ribbed group (using Link Ribbed stem; n = 14), Synergy group (using Synergy stem; n = 9), and Link Classic Uncemented (LCU) group (using LCU stem; n = 14), according to the design of the stem. The clinical and radiographic outcomes were evaluated.

RESULTS

All patients were followed for 36 months. The time of bone union of the LCU stem was significantly longer than that of the Synergy stem (P = 0.02) and the Ribbed stem (P > 0.05); the time of bone union of the Ribbed stem was longer than that of the Synergy stem (P > 0.05). The length of stem in the distal femur of the Ribbed stem (P = 0.000) and the Synergy stem (P = 0.001) is significantly longer than that of the LCU stem. There were three hips with malunion, stem loosening, and varus alignment, which were observed in the LCU stem. None of these were observed in Ribbed and Synergy stems. In total hip arthroplasty with a noncemented stem combined with subtrochanteric femoral osteotomy for Crowe IV DDH, 89.2% hips (33/37) can achieve good and excellent clinical outcomes. There were three hips (1 hip in the Ribbed stem and two in the LCU stem) with fair clinical outcomes and one hip (LCU stem) with poor clinical outcomes.

CONCLUSIONS

Although Ribbed, Synergy, and LCU stems have similar clinical outcomes, the LCU stem has a tendency to a varus position, longer union time, malunion, and stem loosening, when compared with the Ribbed and Synergy stems. We recommend against adoption of the LCU stem for Crowe IV DDH with subtrochanteric femoral osteotomy.

LEVEL OF EVIDENCE

Level III, therapeutic study.

An oblique osteotomy is better for subtrochanteric shortening in total hip arthroplasty for high hip dislocation: a mechanical comparison of four techniques

BACKGROUND

Subtrochanteric femoral shortening is used during total hip arthroplasty for high hip dislocation in developmental dysplasia of hip patients.

METHODS

We mechanically tested the stability of various commonly used subtrochanteric osteotomy techniques. As the equivalent of a femoral stem placed in a shortened femur without any stable fixation at the osteotomy line, 2 polyvinylchloride pipes were loosely intertwined. 4 different osteotomies (Z-subtrochanteric osteotomy, oblique-45° osteotomy, double Chevron-90° and 120° subtrochanteric osteotomy) were simulated. Torsional and axial loads were applied, and torsional stiffness was calculated for each test model.

RESULTS

Z, double Chevron-90° and 120° subtrochanteric osteotomy models demonstrated lower mean torsional stiffness than oblique-45° osteotomy. With the highest torsional stiffness oblique-45° provides the best stability for treatment of high dislocation hips when a subtrochanteric osteotomy is added.

CONCLUSIONS

This matches our previous clinical experience. Oblique osteotomy may also provide higher contact surfaces in the osteotomy lines to promote bone healing.

Cementless modular total hip arthroplasty with subtrochanteric transverse shortening osteotomy for high hip dislocations

Background

Performing a total hip arthroplasty for a high hip dislocation is technically demanding and presents several challenges, with appropriate evaluation of the bone morphology of the hip and proper implant selection being critical for successful outcomes.

Objective

The purpose of our study was to evaluate the clinical and radiographic outcomes of cementless modular total hip arthroplasty for the treatment of high hip dislocations with sub-trochanteric transverse shortening osteotomy.

Methods

Sixty-eight hips with a high hip dislocation, were treated using a sub-trochanteric transverse shortening osteotomy and cementless modular total hip arthroplasty, retrospectively reviewed. Hip function was assessed using the Harris hip score, with hip abduction strength evaluated using the Trendelenburg test. Radiographic assessment included the measurement of leg length discrepancy, identification of implant loosening, localization of the hip center, and union at the osteotomy site.

Results

The mean follow-up period was 12.9 (range 5.2–16.8) years. The mean Harris hip score improved from a pre-operative score of 48.6 ± 3.6 to 82.4 ± 4.2 (p < 0.05). The hip was within the true acetabulum in all patients, postoperatively. Osteotomy union was achieved in 67 of the 68 hips (98.5%) in a mean latency of 12.5 ± 0.6 weeks. The mean length of femoral shortening was 66.5 ± 4.5 mm, with a mean pull-down length of the proximal part of 35.5 ± 3.5 mm.

Conclusion

For the treatment of high hip dislocations with satisfactory clinical outcomes, the modular stem offers an adjustable anteversion angle to restore sufficient rotational stability and the transverse osteotomy provides sufficient compression pressure across the osteotomy site to facilitate union.

Trial registration It was a retrospective study and approved by Istanbul Research and Training Hospital institutional Ethics Review Board (772-05/02/2016).

[A comparative study of three different fixation methods after subtrochanteric shortening osteotomy in total hip arthroplasty for Crowe type Ⅳ developmental dysplasia of the hip]

Objective

To compare the effectiveness of three different fixation methods after subtrochanteric shortening osteotomy (SSO) in total hip arthroplasty (THA) for Crowe type Ⅳ developmental dysplasia of the hip (DDH).

Methods

A clinical data of 63 patients (78 hips) with Crowe type Ⅳ DDH, who underwent THA with SSO between November 2014 and May 2019, was retrospectively analyzed. Among them, 18 patients (20 hips) obtained stability by intramedullary pressure provided by the S-ROM modular prostheses (group A); 22 patients (30 hips) underwent prophylactic binding by stainless steel wire after osteotomy and before stem implantation (group B); 23 patients (28 hips) were fixed with autogenous cortical strut grafts and stainless steel wire or cables (group C). There was no significant difference in gender, age, body mass index, affected limb side, and preoperative Harris score between groups ( P>0.05). The operation time, complications, imaging results, hip functional score of the three groups were recorded and compared.

Results

There was no significant difference in the operation time between groups ( P>0.05). All incisions healed by first intention. All patients were followed up, and the follow-up time was 2.5-4.0 years (mean, 3.1 years) in group A, 1.5-5.5 years (mean, 3.2 years) in group B, and 1.0-5.0 years (mean, 1.6 years) in group C. There was no significant difference in Harris score or Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score between groups at 4 and 12 months after operation ( P>0.05). X-ray films showed that there was no significant difference in osteotomy healing rate at 4, 8, and 12 months after operation and the osteotomy healing time between groups ( P>0.05). There was no complications such as joint dislocation, prosthesis loosening, prosthetic joint infection, or heterotopic ossification during follow-up, except for the distal femoral fracture of 1 hip during operation in group B.

Conclusion

In THA for patients with Crowe type Ⅳ DDH, the stainless steel wire binding alone and autogenous cortical strut grafts combined with stainless steel wire or cable binding can not significantly promote the osteotomy healing compared with femoral prosthesis intramedullary compression fixation. For patients with nonmatched medullary cavity after SSO, it is recommended to apply autogenous cortical strut grafts with wire or cables for additional fixation.

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.

Patient-Specific Instrument Guided Double Chevron-Cut Distal Femur Osteotomy

The risk of non-union and prolonged periods of protected weight-bearing still remain unsolved issues after distal femur osteotomy (DFO). To improve the stability, we developed the double chevron-cut technique, which is a modified medial closing-wedge DFO guided by a patient-specific instrument. The purpose of this study was to investigate the feasibility and outcome of this operative approach. Twenty-five knees in twenty-three consecutive patients with genu valgum and lateral compartment osteoarthritis that received double chevron-cut DFO were included. The target of correction was 50% on the weight-bearing line (WBL) ratio. Patient-reported outcomes included the Oxford Knee Score (OKS) and the 2011 Knee Society Score (KSS). The mean of the WBL ratio was corrected from 78.7% ± 12.0% to 48.7% ± 2.9% postoperatively. The mean time to full weight bearing was 3.7 ± 1.4 weeks. Union of the osteotomy was achieved at 11.3 ± 2.8 weeks. At a mean follow-up of 17 months, the OKS improved from a mean of 27.6 ± 11.7 to 39.1 ± 7.5 (p = 0.03), and the KSS from a mean of 92.1 ± 13.0 to 143.9 ± 10.2 (p < 0.001). Three patients developed complications, including one case of peri-implant fracture, one of loss of fixation, and one of non-union. The double chevron-cut DFO followed by immediate weight-bearing as tolerated is effective in treating genu valgum deformity and associated lateral compartment osteoarthritis.

Long-Term Outcomes of Total Hip Arthroplasty With Transverse Subtrochanteric Shortening Osteotomy and Modular Stem in Crowe IV Developmental Dysplasia

BACKGROUND

The reconstruction of high dislocation related to developmental dysplasia of the hip (DDH) remains challenging for joint surgeons. The aim of this study is to evaluate the rate of union, the revision rate, functional scores, and complications in patients with Crowe IV DDH treated with total hip arthroplasty, transverse subtrochanteric shortening osteotomy, and modular stem in an average 10-year follow-up.

METHODS

Twenty-eight patients (33 hips) with Crowe IV DDH who were operated on between 2008 and 2013 were followed. All patients underwent uncemented total hip arthroplasty with transverse subtrochanteric shortening osteotomy and anatomical acetabular cup implantation. The mean age was 36.6 years, and the mean follow-up period was 121 months. Clinical and radiological outcomes were evaluated.

RESULTS

The mean Harris Hip Score significantly improved from 47.0 preoperatively to 89.6 postoperatively. The mean limb length discrepancy was significantly reduced from 3.8 to 0.8 cm. The mean osteotomy union time was 6.8 months. At the mean follow-up of 121 months, there were 3 cases of postoperative dislocation, 2 cases of intraoperative fracture, and 1 case of posterior tibial venous thrombosis. No revision occurred, and no signs of component loosening or migration were observed at the last follow-up.

CONCLUSION

Crowe IV DDH patients treated with transverse subtrochanteric shortening osteotomy, modular stem, and anatomic acetabular component insertion can have satisfactory and reliable 10-year clinical outcomes.

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.

Satisfactory Outcomes in Patients Operated With Primary Total Hip Arthroplasty for Perthes-like Deformities: Results From a Surgical Technique Utilizing a Conical Stem, an Elevated Hip Center, and No Shortening Femoral Osteotomy

Background

Total hip arthroplasty (THA) performed on patients with Perthes-like deformities are technically challenging because of the patient's abnormal hip anatomy. Patients with Perthes-like deformities are at a higher risk of revision, aseptic loosening, nerve injury, and intraoperative fracture after THA, especially if shortening osteotomies are performed. This analysis sought to examine the clinical and radiographic outcomes of a patient cohort with Perthes-like deformities receiving THA with a conical stem, an elevated hip center, and no shortening femoral osteotomy.

Methods

Twenty-six patients (27 hips) received THA with MODULUS femoral stems, ceramic or metal femoral heads, and highly cross-linked polyethylene liners between April 2011 and March 2016. All patients were treated at a single center by 4 participating surgeons. Patients completed 2 questionnaires preoperatively and at the final follow-up visit (between 1 and 5 years postoperatively): Harris Hip Score and Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire. Differences in patient-reported outcome measures (PROM) scores were measured by paired t-tests. Preoperative and postoperative anteroposterior radiographs were analyzed to monitor patient outcomes.

Results

Significant clinical improvements were observed in all individual subcategories of the Harris Hip Score and of the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire; the largest magnitude improvements were observed in the subcategory of pain relief for both questionnaires. No complications, including intraoperative and postoperative femoral fractures, nerve palsy, dislocations, or deep venous thrombosis, were observed.

Conclusion

This study found that patients treated with an elevated hip center and low stem-positioning technique using a conical, modular implant system had good clinical outcomes and did not suffer complications at the mean follow-up from surgery of 2.8 years (range: 1-5 years).

Comparison of Trochanteric Slide and Subtrochanteric Shortening Osteotomy in the Treatment of Severe Hip Dysplasia: Mid-Term Clinical Outcomes of Cementless Total Hip Arthroplasty

BACKGROUND

The aim of this study is to compare clinical results of Crowe type III-IV developmental dysplasia of the hip (DDH) patients who underwent total hip arthroplasty with either trochanteric slide osteotomy (TSO) or subtrochanteric shortening osteotomy (SSO).

METHODS

The patients who underwent cementless total hip arthroplasty with femoral shortening osteotomy due to Crowe type III/IV DDH between 2004 and 2014 and completed at least 5 years of follow-up were retrospectively analyzed. The patients were grouped according to the type of shortening osteotomy as either TSO or SSO. Preoperative and postoperative clinical evaluation included Harris Hip Score, Visual Analogue Scale pain, leg length discrepancy, and the presence of Trendelenburg sign. The clinical outcome measures and complication rates were compared in terms of osteotomy type.

RESULTS

The TSO group consisted of 34 patients (43 hips) and the SSO group consisted of 40 patients (51 hips). The SSO group (96.1%) had a slightly higher 5-year survival of the implant compared to TSO (93%) without statistical significance (P = .18). No significant difference was detected between the groups in terms of clinical outcomes. Complication rates did not significantly differ between the groups except for the lack of bony union which was significantly higher in TSO (P = .006) but this difference did not transform into clinical significance since 5 of 6 patients who did not have a bony union in the TSO group were symptom-free with a fibrous union.

CONCLUSION

TSO and SSO provide similar clinical outcomes at mid-term follow-up in the management of Crowe III-IV DDH by cementless total hip arthroplasty. Both techniques can be used safely depending on the surgeon's preference.

LEVEL OF EVIDENCE

Level III, Therapeutic, Case-control study.

Clinical and Radiological Results of Crowe Type 3 or 4 Dysplasia Patients Operated on With Total Hip Arthroplasty Using a Cementless Rectangular Femoral Component Without Fixating or Grafting the Transverse Osteotomy Site

BACKGROUND

Total hip arthroplasty (THA) involving shortening osteotomy for patients with Crowe type 3 or 4 dysplasia is a challenging surgical procedure. This study aims to demonstrate that rectangular femoral component use in anatomical reconstructions with THA and transverse shortening osteotomy yields successful results without the use of bone graft or any fixation material at the osteotomy site.

METHODS

Fifty hips from 41 patients were identified retrospectively as per study objectives. All patients were evaluated using the Harris Hip Score and Visual Analog Scale for pain. Complications were reported. Radiological evaluation criteria were then evaluated, including leg length discrepancy, degree of trochanter caudalization and stem subsidence, radiolucent and radiodense lines for both components and bone atrophy or hypertrophy around the stem according to Gruen zones, and the canal fill ratio of the stem.

RESULTS

Postoperative Harris Hip Score was excellent for 68% of patients. No patient had poor results. Complication rate was 32%. One patient had nonunion (2%). The mean postoperative leg length discrepancy was 0.8(±0.6) cm. No patient had a subsidence of more than 5 mm. Radiolucent and radiodense lines were present in up to 34% of patients, and bone atrophy was present in the proximal femur in up to 96% of patients. No patient had osteolysis or loosening in neither component.

CONCLUSION

Successful clinical and radiological results can be obtained from Crowe type 3 and 4 dysplastic hips operated on with THA using a rectangular femoral component and transverse shortening osteotomy technique. The use of graft or any fixation material at the osteotomy site is not mandatory.

Use of proximal humerus plates for the fixation of the subtrochanteric femoral shortening osteotomy during total hip arthroplasty for Crowe type IV developmental dysplasia of the hip patients

OBJECTIVES

This study aims to evaluate the efficacy of proximal humerus plate in the fixation of subtrochanteric femoral shortening osteotomy (SFSO) during total hip arthroplasty.

PATIENTS AND METHODS

Thirty female patients (mean age 49.8 years; range, 22 to 68 years) who underwent hip arthroplasty with a SFSO and fixed with a proximal humerus plate between January 2014 and June 2018 were evaluated retrospectively. Rate of fracture healing, the number of fixed cortices at both sides of the osteotomy, and complications were documented.

RESULTS

The mean follow-up period was 28 months (range, 12-68 months). The average time to union was 106 days (range, 45-229 days). The mean number of cortices fixed in the proximal segment of the osteotomy was 6.2 (range, 4-9), and the mean number of cortices fixed in the distal segment of the osteotomy was 4.0 (range, 3-7). None of the patients had implant irritation or implant failure at the control visits. We observed only one non-union and our non-union rate was 3.3%.

CONCLUSION

In conclusion, the use of a proximal humerus plate for the fixation of SFSO can be an alternative procedure for achieving adequate rotational stability until a solid union.

Optimal location of subtrochanteric osteotomy in total hip arthroplasty for crowe type IV developmental dysplasia of hip

BACKGROUND

When reconstructing a hip with developmental dysplasia and high dislocation, sub-trochanteric shortening osteotomy is typically needed for placing the acetabular component in the appropriate anatomical position. However, the procedure can result in complications such as non-union of the osteotomy. We evaluated the contact area and the coincidence rate between the proximal and distal fragments at different femoral osteotomy levels and lengths. We then determined the optimal location of subtrochanteric femoral shortening transverse osteotomy in patients with unilateral Crowe type IV developmental dysplasia of the hip (DDH). The consistency between the proximal and distal segments was assessed as a possible predictive indicator of the union at the osteotomy site.

METHODS

We retrospectively reviewed 57 patients with unilateral Crowe type IV DDH who underwent X-ray imaging of both hip joints. We labelled the inner and outer diameters of the circular ring as N (mm) and M (mm), respectively. We defined the overlapped area between the proximal and distal ring as contact area S (mm²), and the ratio of contact area to distal ring area as coincidence rate R.

RESULTS

N varied from 9.8-15.2 mm and M varied from 20.7-24 mm, both demonstrated a decreasing trend in the proximal to distal direction. At osteotomy lengths ranging from 0.5-2 cm, there were no differences in S between the different levels of osteotomy in each group. At osteotomy lengths ≤2.5 cm, a significant higher coincidence rate was noted from 2 cm below the lesser trochanter to other positions below the level. At osteotomy lengths from 3 to 5.5 cm, a significantly higher coincidence rate was observed from the level of 1.5 cm below the lesser trochanter to other positions below the level.

CONCLUSIONS

Our findings suggest that femoral shortening transverse osteotomy at the optimal subtrochanteric level can predictably increase the contact area and coincidence rate, which may contribute to the union at the osteotomy site. Considering the stability of the prostheses, it appears appropriate that osteotomy location should be shifted slightly distally.

TRIAL REGISTRATION

Retrospectively registered.

Leg Length Balance in Total Hip Arthroplasty for Patients with Unilateral Crowe Type IV Developmental Dysplasia of the Hip

Objective

To explore the leg length balance in total hip arthroplasty (THA) with shortening subtrochanteric osteotomy (SSTO) or not for unilateral Crowe type IV developmental dysplasia of the hip (DDH) through the evaluation of postoperative full‐length anteroposterior radiographs.

Methods

The postoperative radiographs of 60 patients with unilateral Crowe type IV DDH from July 2012 to May 2019 were retrospectively reviewed. All patients underwent THA using the Pinnacle Acetabular Cup system, a ceramic liner and femoral head, and the S‐ROM stem with a proximal sleeve or cone. Patients with leg length discrepancy (LLD) < 10 mm were defined as the non‐LLD group. To identify differences associated with SSTO, the group was further divided into two groups based on whether the patient underwent SSTO. A total of 48 patients (26 for SSTO and 22 for non‐SSTO) were in the non‐LLD group. There were 3 male and 45 female patients. The mean age of the patients in the non‐LLD group was 39 years. These data, including leg length, femoral length, the height of center of rotation (COR) of the hip, the depth of the sleeve or cone in the femoral medullary canal and the height of the greater trochanter, were measured.

Results

In the non‐LLD group, the femoral lengths in both SSTO and non‐SSTO groups were significantly shorter on the operated side compared with the contralateral side, and the mean discrepancy in the SSTO group was approximately equal to the mean length of the SSTO. The mean height of the COR of the hip on the operated sides in both SSTO and non‐SSTO groups was 13.2 mm, and the contralateral sides were 15.2 and 15.5 mm, respectively. The depth of the sleeve or cone in the femoral medullary canal between SSTO and non‐SSTO groups was 21.7 and 30.6 mm, respectively. The depth of the sleeve or cone in the SSTO group was negatively correlated with the length of SSTO. The heights of the greater trochanter in the operated and contralateral sides were 5.3 and 16.6 mm in the SSTO group, and 13.2 and 17.2 mm in the non‐SSTO group, respectively.

Conclusions

Shortening subtrochanteric osteotomy led to femoral shortening on the operated side for patients with unilateral Crowe type IV DDH. The position of the sleeve or cone should be close to the apex of the greater trochanter to compensate the length of the SSTO. The position of the sleeve or cone without SSTO should be adjusted to make sure that the height of the greater trochanter on the operated side is close to that on the contralateral side.

Total Hip Arthroplasty for Crowe Type IV Hip Dysplasia: Surgical Techniques and Postoperative Complications

Total hip arthroplasty (THA) of Crowe type IV developmental dysplasia of the hip (DDH) is challenging. Although traditional (lateral, posterolateral, and posterior) THA approaches have been used with great anatomic success, they damage periarticular muscles, which are already quite weak in type IV DDH. The recently developed direct anterior approach (DAA) can provide an inter‐nerve and inter‐muscle approach for THA of type IV dysplasia hips. However, femur exposure with the DAA could be difficult during surgery and it is hard to apply femoral shortening osteotomy. THA techniques used for type IV DDH include anatomic hip center techniques (true acetabular reconstruction) and high hip center techniques, wherein an acetabulum is reconstructed above the original one. Although anatomic construction of the hip center is considered “the gold standard” treatment, it is impossible if the anatomical acetabular is too small and shallow. Procedures used to support type IV DDH reduction with anatomic hip center techniques include greater trochanter osteotomy, lesser trochanter osteotomy, and subtrochanteric osteotomy. However, these techniques have yet to be standardized, and it is unclear which is best for type IV DDH. One‐state and two‐state non‐osteotomy reduction techniques have also been introduced to treat type IV DDH. Potential complications of THA performed in patients with type IV DDH include leg length discrepancy (LLD), peri‐operative femur fracture, nonunion of the osteotomy site, and nerve injury. It is worth noting that nowadays an increasing number of Crowe type IV DDH patients are more sensitive to postoperative LLD.

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.

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.

The causes and management of nonunion of femoral subtrochanteric shortening osteotomy in a THA patient: a case report

Background

Total hip arthroplasty (THA) is considerably difficult to perform in patients with Crowe type IV developmental dysplasia of the hip (DDH). Some Crowe type IV DDH patients require a femoral subtrochanteric shortening osteotomy to equalize the length of the lower extremities and decrease the difficulty of intraoperative reduction. Subtrochanteric transverse osteotomy has been proven to have superior clinical efficacy, but some cases of nonunion occur.

Case presentation

We present the case of a 62-year-old male patient who underwent right THA with femoral subtrochanteric transverse osteotomy due to Crowe type IV DDH. Nonunion of the osteotomy occurred during the follow-up period. In July 2017, the patient underwent right THA and femoral subtrochanteric transverse osteotomy due to Crowe type IV DDH. In November 2017, a slight feeling of bone rubbing and slight pain in the hip were reported. The ends of the osteotomy had rotated and united poorly. However, the patient requested to undergo continued observation. In December 2017, the patient reported an obvious sensation of bone rubbing and aggravated hip pain. The ends of the osteotomy had rotated and continued to exhibit nonunion. On December 26, 2017, the patient was treated with plate and screw internal fixation with bone morphogenetic protein (BMP) following our suggestion. In August 2018, the ends of the osteotomy had united after internal fixation was applied.

Conclusions

THA with femoral subtrochanteric transverse osteotomy exhibits good efficacy for the treatment of patients with Crowe type IV DDH. However, postoperative nonunion occurs in a small number of cases. The causes of nonunion should be analysed, and effective measures should be taken to prevent this situation. Plate and screw internal fixation with BMP is an effective treatment for nonunion of the ends of an osteotomy.

Total hip arthroplasty with rectangular stems and subtrochanteric transverse shortening osteotomy in Crowe type IV hips: a retrospective study

Background

The complexity of femoral and acetabular anatomy and restoring anatomic center of hip rotation in Crowe type IV developmental dysplasia of the hip (DDH) complicates standard reconstruction. The aim of this study is to evaluate surgical techniques and clinical outcomes of subtrochanteric transverse shortening osteotomy with the use of cementless rectangular cross-section femoral implants in Crowe IV dysplastic hips.

Methods

A total of 26 hips of 25 consecutive patients with Crowe type IV DDH who underwent cementless total hip arthroplasty with subtrochanteric femoral transverse shortening osteotomy were retrospectively analyzed. The Harris Hip Score, Visual Analog Scale-pain, leg length discrepancy, and vertical and lateral migration of hip rotation center were recorded.

Results

Mean age, follow-up, and time of union were 41 ± 9.7 years, 7.1 ± 1.2 years, and 3.7 ± 1.1 months, respectively. Mean Harris Hip Score significantly improved from 38 ± 5.7 to 86 ± 6.1 points postoperatively (P < .01). Mean leg length discrepancy and Visual Analog Scale significantly decreased from 4.3 ± 1.3 to 1.2 ± 0.6 cm, and 6.4 ± 1.2 to 1.8 ± 0.8 points, respectively (P < .01). One female patient had a dislocation due to acetabular liner wear, which was managed by liner and head change. One patient had Sudeck's atrophy, while another had pain on the lateral thigh, both of which were resolved with conservative management.

Conclusions

Combined transverse subtrochanteric femoral osteotomy and cementless total hip arthroplasty with rectangular cross-section femoral implants is technically demanding, effective, and safe in femoral shortening for treatment of Crowe type IV DDH.

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.

Impact of acetabular reaming depth on reconstruction of rotation center in primary total hip arthroplasty

PURPOSE

To study the impact of acetabular reaming depth on reconstruction of rotation center (RC) in unilateral primary total hip arthroplasty (UPTHA) and guide individualized preoperative design.

METHODS

200 postoperative standard bilateral hip anteroposterior radiographs after UPTHA were included, which were collected from January, 2013 to June, 2017 in our hospital. Osteonecrosis of femoral head was the only diagnosis in this cohort. The parameters were measured on the anteropoterior radiographs by using RadiAnt DICOM viewer.

RESULTS

The average of the thickness of the teardrop is about 6.13 ± 1.42 mm. The parameter a (the difference value of the distance of bilateral RC and midline) was positively correlated with the parameter e (the acetabular reaming depth), and the Pearson correlation coefficient was 0.49 when P = 0.05. Furthermore, the value of parameter (e) was 8.25 mm when a2 (the distance from the center of the prosthesis femoral head to the vertical line across the midpoint of pubic symphysis) equaled a1 (the distance from RC of the healthy femoral head to the vertical line across the midpoint of pubic symphysis).

CONCLUSIONS

The reaming depth of the acetabulum could influence the reconstruction of RC during UPTHA. When the medial margin of the cup was placed about 2 mm to the lateral border of the ipsilateral teardrop (the bottom of the ovum), the rotation center would be accurately restored.

Cementless total hip arthroplasty for severely dislocated hips previously treated with Schanz osteotomy of the proximal femur

INTRODUCTION

We report the short-term outcomes of total hip arthroplasty(THA) in patients previously treated with Schanz osteotomy (SO).

MATERIALS AND METHODS

Eighteen patients [2 male, 16 female; mean age, 55.4 (range, 50-66) years] who had undergone THA after SO were retrospectively evaluated. Clinical evaluation was performed based on the Harris hip score. Radiological evaluation was performed using full-length radiographs of the lower extremities, pelvis, and hip.

RESULTS

The mean follow-up period was 30.8 (range, 18-56) months. Mean femoral shortening was 3.7 (range, 2-5) cm. Perioperative complications occurred in 4 (22.2%) patients. Nonunion was not found at the osteotomy sites. No dislocation was observed. The Trendelenburg sign was positive for five (27.7%) patients, postoperatively. The mean Harris hip score improved from 42.7 to 78.7 (p < 0.05).

CONCLUSION

THA for hips previously treated with SO is technically demanding. If careful preoperative planning is performed, successful treatment can be achieved.

Results of Crowe Type IV Developmental Dysplasia of Hip Treated by Subtrochantric Osteotomy and Total Hip Arthroplasty

BACKGROUND

Crowe type IV developmental dysplasia of hip (DDH), subtrochanteric shortening osteotomy is required to restore the hip joint. Several approaches have been described for subtrochanteric shortening osteotomy. Several osteotomy fixation techniques have been defined for Crowe type IV DDH. This study evaluates the outcomes of subtrochanteric shortening osteotomy fixed with a combination of split onlay autograft and distal fluted femoral stem.

MATERIALS AND METHODS

A retrospective study was carried out on 41 hips of 37 patients treated with total hip replacement for Crowe type IV developmental dysplasia of the hip by subtrochanteric transverse osteotomy and fixed with split intercalary autograft by two cables. A femoral stem with proximal coated and distally fluted was used. The patients were evaluated at a mean of 34 months (range 12-68 months) for union time, leg equalization, and clinical outcomes.

RESULTS

Mean time of union was 13.5 ± 4.6 weeks (range 6-24 weeks). Intraoperative instability of the osteotomy site (n = 16) that was encountered at the trial stage was restored properly by this surgical protocol. Leg length discrepancies were improved to 1.4 ± 0.8 cm (range 0-3 cm). Harris scores were improved from 47.7 ± 10.8 (range 30-68) to 88 ± 5.6 (range 72-98) (P < 0.05) points. There was no nonunion.

CONCLUSIONS

Distally well-fitted stem and strengthening of fixation with split intercalary autograft promote additional rotational stability and improve bone union.

Subtrochanteric shortening osteotomy during cementless total hip arthroplasty in young patients with severe developmental dysplasia of the hip

BACKGROUND

This retrospective study was designed to determine complications, functional and radiographic results of transverse subtrochanteric osteotomy during cementless, modular total hip arthroplasty (THA) in a series of active patients younger than 45 years with Crowe Type-III or IV developmental dysplasia of the hip (DDH).

METHODS

We followed 49 patients (56 hips) with DDH who were treated with cementless THA, where the acetabular cup was positioned in the anatomic hip center and where a simultaneous transverse femoral osteotomy was performed. Complication rate evaluation and clinical outcomes were measured by validated clinical scores and radiographic evaluation were performed at a mean follow up of 10 years (range, 4.8-14.3 years).

RESULTS

The mean limb-length discrepancy was reduced from 4.2 cm to 1.1 cm (P < 0.01). The mean Harris hip score (HSS) significantly improved from 40.6 points to 87.4 points (P < 0.01). Similarly, severity of low back pain, modified MAP, HOOS, and SF-12 also showed significant improvement (P < 0.01). There were 3 cases of postoperative dislocation, 3 cases of transient nerve palsy, 2 cases of nonunion, and 4 cases of intraoperative fracture. At 10 years follow-up, the estimated survival rate with any component revision as end points was 92%.

CONCLUSION

The cementless THA combined with transverse subtrochanteric osteotomy is a reliable technique with restoration of a more normal limb, satisfactory clinical outcomes, and mid-term survival of components.

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.

Subtrochanteric femoral shortening osteotomy combined with cementless total hip replacement for Crowe type IV developmental dysplasia: a retrospective study

Background

Total hip replacement for high dislocation of the hip presents some difficulties, considering patients’ young ages, the abnormal hip anatomy and the high rate of complications. In this study, we present our experience in terms of clinical and radiological results in the treatment of Crowe type IV hips with subtrochanteric femoral shortening osteotomy and cementless total hip replacement.

Materials and Methods

We retrospectively reviewed 15 patients with Crowe type IV hip dysplasia (two bilateral cases for a total of 17 hips) treated with cementless total hip replacement associated with shortening subtrochanteric osteotomies (nine transversal and eight Z-shape osteotomies) between March 2000 to February 2006. The mean follow-up was 88 months (range 63–133). Harris hip score, leg length discrepancy, neurological status, union status of the osteotomy and the component stability were the criteria of the evaluation. All complications were noted.

Results

The mean HHS improved from 38.3 (range 32–52) to 85.6 (range 69–90). The mean preoperative leg length discrepancy was of 45 mm (range 38–70) and reduced to a mean of 12 mm (range 9–1.6) postoperatively. All osteotomies resulted healed at an average of 12.3 weeks (range 10–15). No cases of delayed union or nonunion were detected. Two patients (11%) showed early symptoms of sciatic nerve palsy which resolved uneventfully in 6 months. There was no migrations and none of the implants required revision.

Conclusions

Cementless THA with shortening subtrochanteric osteotomy is an effective method in the treatment of patients with Crowe type IV development dysplasia of the hip.

Level of evidence

IV.

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 with step-cut subtrochanteric femoral shortening osteotomy in high riding hip dislocated patients with previous femoral osteotomy

BACKGROUND

To evaluate the long-term clinical and radiological outcomes of cementless total hip arthroplasty (THA) in high riding hip dislocated patients with previous proximal femoral osteotomy.

METHODS

Twenty-one consecutive patients with a mean age forty-two years were treated with cementless THA Step-cut subtrochanteric femoral osteotomy was performed in all twenty-eight hips. Metal on polyethylene (MoP) and ceramic on ceramic (CoC) bearings were used in two different consecutive time periods. The mean follow-up time was twelve years. Harris hip score, limb length discrepancy, complications, union status of the osteotomy, survivorship of constructs were the criteria for evaluation.

RESULTS

The mean Harris hip score improved from 39.5 to 88.7 points. The mean limb length discrepancy in unilateral cases decreased from 54.5 mm to 12.3 mm. The mean amount of femoral shortening was 37 mm. The mean union time was 3.5 months and there were no delayed union and non-union. There were three cup and two femoral revisions due to osteolysis in patients who had MoP. There was only one femoral revision in patients who had CoC. The Kaplan Meier survivorship with an end point of any revision of the stem and the acetabular component was 94% (95% CI, 75%-98%) and 92% (95% CI, 74%-99%) at ten years respectively.

CONCLUSIONS

Total hip arthroplasty with subtrochanteric step-cut femoral shortening is a successful technique to improve the hip functions and reconstruct limb length discrepancy in young patients with proximal femoral deformities.

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.

Total hip arthroplasty without femoral osteotomy in patients who had high and low dislocation due to developmental dysplasia of the hip

BACKGROUND

Various surgical techniques and outcome results have been reported after primary total hip arthroplasty for the treatment of patients dysplastic hips. Low failure and complication rates have been reported when the acetabular component has been placed in the true acetabulum. The current study reports the results of primary total hip arthroplasty in patients with high and low dislocation for whom the acetabular component was placed in the true acetabulum without femoral or trochanteric osteotomy.

METHODS

26 primary total hip replacements were performed on 22 patients. The mean duration of follow-up was 8.9 years.There were 4 men and 18 women. 17 hips were classified as type B (low dislocation) and 9 as type C (high dislocation), according to the classification system of Hartofilakidis et al. Acetabular components were placed in the true acetabulum without osteotomy for all patients.

RESULTS

At the time of final follow-up (mean 8.9 years) the average Harris Hip Score was 85 points. Femoral head autograft was used in 9 hips to supplement acetabular coverage. In 8 patient linear calcar fracture. 7 fixed with Dall-Mile cable and 1 fixed with a side plate. On radiologic evaluation, 2 incidents of asymptomatic osteolysis, 1 of acetabular loosening, 1 graft resorption, and 1 impingement (correlated with physical examination) were identified. 2 patients had neuropraxia and were treated medically. There were no early or late infections. Only 1 patient with acetabular loosening required revision surgery.

CONCLUSIONS

Although it is surgically difficult to place the acetabular component in the true acetabulum without femoral or trochanteric osteotomy, at the final follow-up we report favourable results. Long-term follow-up is needed to verify our results.

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.

Biomechanical comparison of oblique and step-cut osteotomies used in total hip arthroplasty with femoral shortening

BACKGROUND

Various types of shortening osteotomies and prosthesis are used for femoral reconstruction in total hip arthroplasty of the high hip dislocation. This biomechanical study investigates whether step-cut osteotomies result in better stability than oblique osteotomies and cylindrical femoral stems enhance stability of the osteotomy more than conical stems, and which osteotomy and prosthesis type maintain the stability better after cyclical loading.

METHODS

Oblique and step-cut shortening osteotomies were compared under axial and rotational forces, using synthetic femur models and conical or cylindrical femoral prostheses. The models underwent cyclic loading for 10,000 cycles at 3 Hz (100-1000 N axial bending or 0.5-10 Nm torque). After the completion of cyclic loading, the models were loaded until failure. Stiffness values before and after cyclical loading, and failure loads were the outcome parameters. Relative displacements at the osteotomy sites were also measured using 3-Dimensions Digital Imaging Correlation System.

RESULTS

The mean failure load was significantly higher in conical prosthesis groups under axial forces. In torsion tests, the mean stiffness of conical prosthesis groups after cyclical loading was higher in oblique osteotomies. The other parameters were similar between the groups.

CONCLUSIONS

According to the results of the study, although some individual statistically significant parameters were obtained, step-cut osteotomies, which are technically challenging procedures, were not found biomechanically superior to oblique osteotomies, with neither conical nor cylindrical prostheses.

Cementless total hip arthroplasty in developmental dysplasia of the hip with end stage osteoarthritis: 2-7 years' clinical results

Between 2006 and 2011, 102 hips of 78 patients with end-stage osteoarthritis secondary to developmental dysplasia of the hip (DDH) underwent cementless total hip arthroplasty (THA). According to the Crowe's classification, 22 hips (21%) were type 1, 19 hips (18%) were type 2, 22 hips (21%) were type 3 and 39 hips (38%) were type 4 respectively. Functional and clinical analyses were performed by Harris Hip Scores (HHS). There were 73 (71%) excellent or good results according to HHS. The postoperative HHS was significantly lower in patients who underwent femoral shortening (p<0.01). We observed 25 (24.5%) complications in total, 15 (14.7%) of which required revision surgery. The authors concluded that THA for DDH is a safe and a reliable procedure with good clinical outcomes.

How do different designs of femoral stem affect total hip arthroplasty applied to Crowe type III and type IV dysplastic hips

PURPOSE

A comparison was made of the clinical and radiological results of cylindrical fully porous-coated femoral stems (Group A) and Zweymüller-type femoral stems (Group B) used for the treatment of hip osteoathrosis, secondary to Crowe III and IV dysplasia, with total hip arthroplasty combined with femoral transverse shortening osteotomy.

METHOD

This study is a retrospective evaluation of 86 hips in 50 patients. Group A comprised of 43 hips and Group B comprised of 43 hips. During final follow-up evaluation, patients were clinically assessed with Harris Hip Score (HHS), Merle d'Aubigne-Postel scale (MAP), and SF-36 scale. For radiological examination the Gulman THA score was used. Femoral osteotomy union, osteolysis around the components and component migration were also recorded and evaluated.

RESULTS

In Group B, nonunion of the osteotomy site was found in 18.6% and delayed union in 20.9% of the hips. In Group A, delayed union was found in 7% of the hips. Patients' mean daily walking distance was found to be lower in Group A when compared to Group B. When the postoperative clinical HSS, and MAP and the radiological Gulman scores were compared, no statistically significant differences (p = 0.275) were found.

CONCLUSIONS

Patients with hip osteoarthritis secondary to Crowe III and IV dysplasia, who were treated with THA and transverse osteotomy showed a higher incidence of osteotomy complications when the Zweymüller femoral stem was used. However, these complications did not affect clinical outcomes.

Biomechanical Comparison of 2 Different Femoral Stems in the Shortening Osteotomy of the High-Riding Hip

BACKGROUND

We hypothesized that a rectangular cross-sectional femoral stem may produce more initial stability of the transverse subtrochanteric femoral shortening osteotomy rather than a circular cross-sectional stem.

METHODS

Twenty, fourth-generation, synthetic femur models were inserted with either circular or rectangular cross-sectional femoral stems after 3 cm of transverse subtrochanteric shortening. Half of the models were tested with axial bending and the other half with torsional loads. After the femora underwent cyclic loading, they were loaded until failure. Outcome parameters were stiffness values before and after cyclical loading, failure loads/torques, and displacements at the osteotomy sites.

RESULTS

In axial bending tests, the results were not significantly different between the groups. Under rotational forces, the mean stiffness value before cyclical loading and failure torque of the cylindrical stems was significantly higher than that of rectangular cross-sectional stems (11.8 ± 1.2 vs 7.1 ± 2.8 Nm/degree; P = .009 and 136.9 ± 60.2 vs 27.1 ± 17.5 Nm; P = .027 Nm, respectively). The mean amounts of displacements at the osteotomy sites were not significantly different between the groups in any direction in both axial and rotational tests.

CONCLUSIONS

According to the results of the study, using straight, cylindrical femoral stems can increase rotational stability of the transverse osteotomy more than the rectangular cross-sectional stems although the latter one has the advantages of rectangular geometrical design.

The results of monoblock stem with step-cut femoral shortening osteotomy for developmentally dislocated hips

INTRODUCTION

The main objective of this study was to evaluate the midterm results of cementless THA with the use of monoblock stems combined with step-cut femoral shortening derotational osteotomy for DDH.

MATERIALS AND METHODS

A total of 66 hips of 49 patients with Crowe type IV developmental hip dislocation, with a mean follow-up of 90 (range 26-207) months, were reviewed retrospectively. Subtrochanteric step-cut shortening osteotomy and monoblock femoral stems were used. The cup was placed in the true acetabulum in all cases. 21 hips had previous femoral valgisation osteotomies. Anteroposterior and lateral radiographs of both hips were obtained preoperatively and at the last follow-up examination. The Harris Hip Score (HHS) was used for pre- and postoperative clinical evaluation.

RESULTS

The mean HHS increased from 49 to 86 points. A total of 13 hips of 10 patients (the isolated acetabular component in 7 hips of 6 patients, the femoral component in 3 hips of 3 patients, and both components in 2 patients) were revised during the follow-up period. Dislocation occurred in 3 hips, deep periprosthetic infection in 2, superficial wound infection in 2, and femoral vein injury and sciatic nerve palsy in 1. Nonunion was observed in 3 osteotomy sites. 10-year survival probabilities of 91% for femoral components for all cases and 78% for acetabular components were found.

CONCLUSIONS

THA with subtrochanteric femoral shortening osteotomy was proven to be an effective technique for avoiding neurological complications for Crowe IV DDH. Cementless THA with the use of monoblock stems showed overall survival rates of 95% at 5 years and 85% at 10 years.

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.