There is no consensus regarding the optimum frequency of ultrasound for monitoring the response to Pavlik harness (PH) treatment in developmental dysplasia of hip (DDH). The purpose of our study was to determine if a limited-frequency hip ultrasound (USS) assessment in children undergoing PH treatment for DDH had an adverse effect on treatment outcomes when compared to traditional comprehensive ultrasound monitoring. This study was a single-center non-inferiority randomized controlled trial. Children aged less than six months of age with dislocated, dislocatable and stable dysplastic hips undergoing a standardized treatment program with a PH were randomized, once stability had been achieved, to our current standard USS monitoring protocol (every clinic visit) or to a limited-frequency ultrasound protocol (USS only until hip stability and then end of treatment). Groups were compared based on alpha angle at the end of treatment, acetabular indices (AI) and IHDI grade on follow up radiographs at one-year post harness and complication rates. The premise was that if there were no differences in these outcomes, either protocol could be deemed safe and effective. One hundred patients were recruited to the study; after exclusions, 42 patients completed the standard protocol (SP) and 36 completed the limited protocol (LP). There was no significant difference between the mean age between both groups at follow up x-ray (SP: 17.8 months; LP: 16.6 months; p=0.26). There was no difference between the groups in mean alpha angle at the end of treatment (SP: 69°; LP: 68.1°: p=0.25). There was no significant difference in the mean right AI at follow up (SP: 23.1°; LP: 22.0°; p=0.26), nor on the left (SP:23.3°; LP 22.8°; p=0.59). All hips in both groups were IHDI grade 1 at follow up. The only complication was one femoral nerve palsy in the SP group. In addition, the LP group underwent a 60% reduction in USS use once stable. We found that once dysplastic or dislocated hips were reduced and stable on USS, a limited- frequency ultrasound protocol was not associated with an inferior complication or radiographic outcome profile compared to a standardized PH treatment pathway. Our study supports reducing the frequency of ultrasound assessment during PH treatment of hip dysplasia. Minimizing the need for expensive, time-consuming and in-person health care interventions is critical to reducing health care costs, improving patient experience and assists the move to remote care. Removing the need for USS assessment at every PH check will expand care to centers where USS is not routinely available and will facilitate the establishment of virtual care clinics where clinical examination may be performed remotely

Several design principles were considered paramount when the surgical technique of performing total hip arthroplasty through an incision in the superior capsule without dislocation of the hip joint was developed. These design principles include: Preservation of the abductors; Preservation of the posterior capsule and short external rotators; Preparation of the femur in situ without dislocation of the hip; In-line access to the femoral shaft axis; Ability to perform a trial reduction; Independence from intraoperative imaging; Independence from a traction table; Applicable to at least 99% of THA procedures. Personal experience with more than 1950 THA using the superior capsulotomy technique over a 12-year period has demonstrated several observations: Dislocation rate of 0.15% (3 in 1950); Acute deep infection rate of 0% (0 in 1950); Universal applicability: used in 99.7% of primary THA; Lateral femoral cutaneous nerve palsy incidence: 0/1950; Femoral nerve palsy incidence: 0/1950; Transient peroneal palsy incidence: 2/1950; Length of stay (since 2010): 1.55 days; Discharge to home: 98%; 90-day cost (2/13 to 2/14) compared to other exposures in CMS patients in the same institution: $24,200 vs $30,100; Readmission costs (CMS 2/13 to 2/14) at 90 days: $0. Conclusion: Performing total hip arthroplasty without dislocation and with preservation of the abductors, posterior capsule and short external rotations has proven to have a low dislocation rate, a low infection rate, and wide applicability. CMS 12-month expenditure data documenting ZERO dollars spent on readmission for any reason within 90 days of surgery demonstrates the potential for simultaneously improving incomes and reducing cost, with particular benefit within the CMS BPCI and private bundled payment programs

Traditional risk factors for post-operative neuropathy include learning curve of surgical approach, DDH, and significant leg lengthening (>1 inch). Despite these risk factors, the most common scenario of a neuropathy is in a routine THA, by an experienced surgeon, for osteoarthritis, with no leg lengthening. Post-operative hematoma can lead to nerve compression, albeit rarely. The usual clinical presentation is of an acute event, with a previously intact nerve, sometime within the first days of surgery. Once diagnosed, immediate surgical decompression should be performed. Sciatic neuropathy is the most common, regardless of surgical approach, but the posterior approach poses the highest risk. Routine gluteus maximus tendon release may help to reduce the risk. When seen in the PACU, our approach is to immediately perform CT imaging to evaluate nerve integrity or to check on acetabular screw position. If no underlying cause is identified, the patient will be managed conservatively with foot orthotics and monitored for recovery. Femoral nerve palsy (FNP) can result in significant initial disability. Fortunately most patients recover function (although it can take over 18 months). In the early post-operative period it is often diagnosed after a patient complains of the leg giving away while attempting to walk. A knee brace will assist the patient with mobilization while the nerve recovers. The highest incidence of FNP is described for the direct lateral approach. Superior gluteal nerve (SGN) palsy is related to the direct lateral approach and may be avoided if the gluteus medius split is made within the safe zone (<5 centimeters from the tip of the greater trochanter). While early post-operative limp is common after the direct lateral approach, the true reported incidence of SGN palsy is low. Few studies showed that the persistent positive Trendelenburg test and limp is not exclusively related to the SGN damage and therefore the clinical effect of the SGN damage remains controversial. Lateral femoral cutaneous nerve can be affected during the direct anterior hip approach. One study suggests the presence of peri-incisional numbness in over 80% of patients. This is akin to numbness seen lateral to the incision after TKA. The incidence of meralgia paresthetica is extremely low (<1%)

Background:. The direct anterior approach (DAA) is one of the muscle sparing approaches in total hip arthroplasty (THA). The advantages of the DAA-THA include low dislocation rate, quick recovery with less pain, and accurate implantation. However, complications related to the learning curve have been reported. The aim of this study was to analyze the first 100 cases of DAA-THA performed by 2 surgeons. Methods:. The records of first 100 consecutive primary DAA-THAs performed by 2 orthopedic surgeons who have np experience of DAA-THA previously were retrospectively reviewed. All operations were performed using DAA in the supine position without the special traction table. The surgical result, the early clinical results, complications, and accuracy of prosthesis placement were investigated. Results:. The mean intraoperative blood loss was 424 ± 216 m. The mean operative time was 55.4 ± 17.5 minutes. One-hundred and ninety-one cups (96%) were placed within the Lewinnek's safe zone. The overall complication rate was 6% (12 hips), including 5 proximal femoral fracture, 3 stem subsidence, 2 temporal femoral nerve palsy, and 2 cup migration. No revision surgery was required, No postoperative dislocation occurred. Conclusion:. We analyzed the first 100 cases of DAA-THA performed by 2 orthopedic surgeons. We concluded that with appropriate training this procedure can be performed safely and effectively without increasing the risk of complications

Background. Minimally invasive surgery is being widely used in the field of total hip arthroplasty (THA). The advantages of the direct anterior approach (DAA), which is used in minimally invasive surgery, include low dislocation rate, quick recovery with less pain, and accuracy of prosthesis placement. However, minimally invasive surgery can result in more complications related to the learning curve. The aim of this study was to evaluate the learning curve of DAA-THA performed by a senior resident. Methods. Thirty-three consecutive patients (33 hips) who underwent primary THA were enrolled in this study. All operations were performed by a senior resident using DAA in the supine position without the traction table. The surgeon started using DAA exclusively for all cases of primary THA after being trained in this approach for 6 months. Operative time, intraoperative blood loss, complications, and accuracy of prosthesis placement were investigated. Results. The mean intraoperative blood loss was 524 mL (range, 130–1650 m L). The mean operative time was 60 min (range, 41–80 min). Radiographic analysis showed an average acetabular anteversion angle of 17.0±3.3°, abduction angle of 37.8±4.3°, and stem alignment of 0±0.8°. Thirty-two (97%) of 33 cups were placed within the Lewinnek's safe zone. The overall complication rate was 12% (4 of 33 hips), including 1 proximal femoral fracture (salvaged with circumferential wiring), 1 temporary femoral nerve palsy (completely recovered in 2 weeks), 1 stem subsidence (5 mm), and 1 cup migration. Three of these complications were occurred in the first 10 cases. No revision surgery was required, No postoperative dislocation occurred. Conclusion. We investigated the learning curve of DAA-THA performed by a senior resident. We considered the first 10 cases as the learning curve, but concluded that with adequate training this procedure can be performed safely and effectively without increasing the risk of complications

Purpose. This study was undertaken to assess the result of total hip arthroplasty (THA) performed for fused hips. Patients and Methods. Twenty nine patients (31 hips), aged 21 to 70 years (average 46 years), underwent THA conversion surgery and were followed for an average of 4.6 years (2.4-12.0 years). There were 23 cases of spontaneous fusion and 8 case of surgical fusion. The causes of joint fusion were tuberculosis in 6 hips, childhood coxitis in 13, ankylosing spondylitis in 6 and childhood trauma in 4. Modified two incision technique was used in 9 hips and in 22 hips, the surgery was performed through a posterolateral approach combined with anterior capsulotomy through gluteus medius and tensor fasica lata interval. In 1 case, greater trochanter osteotomy was done. All acetabular components were inserted at the true acetabulum and the articulations were metal on metal in 7 cases and ceramic on ceramic in 24 cases. Postoperatively, range of motion exercises were encouraged after 2 to 3 weeks of bed rest and subsequent weight bearing crutch ambulation. Then active exercises were strongly encouraged to stretch abductors. We evaluated the clinical and radiological results. Results. Mean duration of surgery was 178.6 minutes, and mean perioperative blood loss was 1420.1 ml. Post-operative dislocation occurred in 1 case and partial femoral nerve palsy developed in 1 case. Mean Harris Hip Score improved from 42.4 to 84.2 and mean leg lengthening of 36.6 mm was achieved. Sitting cross legged was possible in 15 patients and except 2 patients, all patients were satisfied with the surgery. On the radiologic evaluation, there was no changes in cup position and there was one case with acetabular focal osteolysis. Postoperative dislocation occurred in one case and there was no revision surgery or infection. Conclusion. Our study suggest that THA performed for fused hips with hard bearing articulation can provide good clinical and radiological results in mid-term follow up

Anterior supine intermuscular total hip arthroplasty (ASI-THA) has emerged as a muscle sparing, less-invasive procedure. The anterior interval is both intermuscular and internervous, providing the advantages of little or no muscle dissection, and a true minimally invasive alternative. It is versatile, with reported use expanding beyond the primary realm to revision and resurfacing THA as well as treatment of acute fracture in elderly patients, who due to their diminished regenerative capacity may benefit more from the muscle-sparing nature of the anterior approach. The ASI approach involves the use of a standard radiolucent operative table with the table extender at the foot of the bed and the patient supine. Fluoroscopy is used in every case. A table-mounted femur elevator is utilised to facilitate femoral preparation. A retrospective review identified 824 patients undergoing 934 consecutive primary ASI-THA performed between January 2007 and December 2010. Age averaged 63.2 years (27‐92), BMI averaged 29.9 kg/m2 (16.9–59.2). Gender was 49% males and 51% females. Stem types were short in 82% and standard length in 18%. Follow-up averaged 23.1 months (1‐73). Operative time averaged 63.1 minutes (29‐143). Blood loss averaged 145.3 mL (25‐1000). Transfusion rate was 3.3% (30 of 914) in single procedures and 80% (8 of 10) in simultaneous bilateral procedures. Length of stay averaged 1.7 days (1‐12). Intraoperatively there were 3 calcar cracks and 1 canal perforation treated with cerclage cables. There were 6 wound complications requiring debridement. Four hips had significant lateral femoral cutaneous nerve parathesias not resolved at 12 months. One femoral nerve palsy occurred. At up to 73 months follow-up there have been 21 revisions (2.2%): 2 infection, 1 malpositioned cup corrected same day, 5 metal complications, 2 dislocations, 2 loose cups with one requiring concomitant stem revision secondary to inability to disarticulate trunnion, 1 femoral subsidence and 8 periprosthetic femoral fractures. Primary THA can be safely performed utilising this muscle-sparing approach. We did not see an alarmingly high rate of complications. Instead, rapid recovery and quick return to function were observed. ASI-THA appears to be safe. The recovery advantage utilising this surgical approach is irrefutable. There are complications, most notably periprosthetic femur fracture. The rate, however, appears to be low and decreases with increased experience. There is no need for a special operative or fracture table to perform the procedure. Whether the complication rate is higher with the use of these expensive devices is unknown, but our results demonstrate a 2.2% reoperation rate with the use of the ASI approach performed on a standard OR table. Continued refinement of the technical aspects of ASI-THA may lessen the complication rate

Anterior supine intermuscular total hip arthroplasty (ASI-THA) has emerged as a muscle sparing, less-invasive procedure. The anterior interval is both intermuscular and internervous, providing the advantages of little or no muscle dissection, and a true minimally invasive alternative. It is versatile, with reported use expanding beyond the primary realm to revision and resurfacing THA as well as treatment of acute fracture in elderly patients, who due to their diminished regenerative capacity may benefit more from the muscle-sparing nature of the anterior approach. The ASI approach involves the use of a standard radiolucent operative table with the table extender at the foot of the bed and the patient supine. Fluoroscopy is used in every case. A table-mounted femur elevator is utilised to facilitate femoral preparation. A retrospective review identified 824 patients undergoing 934 consecutive primary ASI-THA performed between January 2007 and December 2010. Age averaged 63.2 years (27–92), BMI averaged 29.9 kg/m2 (16.9–59.2). Gender was 49% males and 51% females. Stem types were short in 82% and standard length in 18%. Follow-up averaged 23.1 months (1–73). Operative time averaged 63.1 minutes (29–143). Blood loss averaged 145.3 minutes (25–1000). Transfusion rate was 3.3% (30 of 914) in single procedures and 80% (8 of 10) in simultaneous bilateral procedures. Length of stay averaged 1.7 days (1–12). Intraoperatively there were 3 calcar cracks and 1 canal perforation treated with cerclage cables. There were 6 wound complications requiring debridement. Four hips had significant lateral femoral cutaneous nerve parathesias not resolved at 12 months. One femoral nerve palsy occurred. At up to 73 months follow-up there have been 21 revisions (2.2%): 2 infection, 1 malpositioned cup corrected same day, 5 metal complications, 2 dislocations, 2 loose cups with one requiring concomitant stem revision secondary to inability to disarticulate trunnion, 1 femoral subsidence and 8 periprosthetic femoral fractures. Primary THA can be safely performed utilising this muscle-sparing approach. We did not see an alarmingly high rate of complications. Instead, rapid recovery and quick return to function were observed. ASI-THA appears to be safe. The recovery advantage utilising this surgical approach is irrefutable. There are complications, most notably periprosthetic femur fracture. The rate, however, appears to be low and decreases with increased experience. There is no need for a special operative or fracture table to perform the procedure. Whether the complication rate is higher with the use of these expensive devices is unknown, but our results demonstrate a 2.2% reoperation rate with the use of the ASI approach performed on a standard OR table. Continued refinement of the technical aspects of ASI-THA may lessen the complication rate

Introduction. Total hip arthroplasty (THA) using the direct anterior approach (DAA) in a supine position is a minimally invasive surgery that reduces postoperative dislocation. Excellent exposure of both the acetabulum and proximal femoral part is important to reduce intraoperative complications. Generally, two surgical assistants need to hold four retractors to maintain excellent exposure of the acetabulum. We examined intra- and postoperative complications as indicators of the efficiency of using the “Magic Tower” (MT) device compared with a non-MT group. Material and Method. Twenty consecutive DAA THAs using MT were analyzed, and 20 DAA THAs not using MT were also analyzed. MT is a retractor-holding device, and has an arm structure that can be moved in a wide variety of directions. This device holds a retractor stably, and each movement of the arm can be locked by one click. Operating time, blood loss, length of skin incision, intraoperative complications, and number of assistants were recorded. Postoperative radiographs were obtained to evaluate implant position. Results. Mean operating time was 105 min in the MT group and 118 min in the non-MT group. Mean blood loss was 232 g in the MT group and 233 g in the non-MT group. Mean length of skin incision was 80 mm in the MT group and 85 mm in the non-MT group. Mean cup inclination was 45.8° in the MT group and 47.3° in the non-MT group. Postoperative implant position was also excellent in both groups. In all comparisons, no significant differences were seen between groups. No intraoperative complications were encountered. Two assistants were required in the non-MT group, and one in the MT group. Discussion. A majority of the complications reported with THA can be attributed to access issues, i.e., difficulties in exposure and accurate component implantation. To achieve excellent exposure at the acetabulum, four retractors (anterior, posterior, cranial, and caudal) are desirable. In such procedures, two surgical assistants are needed to hold retractors. One of these assistants needs to hold the anterior retractor and cranial/caudal retractor from the opposite side of the surgery beyond the abdomen of the patient. However, the assistant on the opposite side cannot achieve good exposure, as strong retraction of the anterior part of the acetabulum may cause complications of femoral nerve palsy. The MT is able to hold a retractor firmly by applying pressure toward the acetabulum instead of traction, and also reduces the number of surgical assistants required. While preparing the femur, exposure of the femoral canal was also better than in the non-MT group. Conclusion. In primary DAA THA, no significant differences between groups were identified. However, the MT is clearly a useful device that allows maintenance of excellent exposure, reducing the number of surgical assistants required

The Gibson and Moore postero-lateral approach is one of the most often used in hip replacement. The advantage of this approach is an easy execution but it's criticized because of its invasivity to muscle-tendinous tissues especially on extrarotators muscles and because of predisposition to posterior dislocation. Since June 2003 we executed total hip replacements using a modified postero-lateral approach which allows to preserve the piriformis and quadratus femoris muscles and to detach just the conjoint tendon (gemelli and obturator internus). Articular capsule is preserved and it will be anatomically sutured at the end of the procedure as well as the conjoint tendon with two transossesous sutures. Piriformis and quadratus femoris muscles result untouched by this approach. We have executed 500 surgeries with this modified approach. We have used different stems (straight, anatomical, modular and short) and press fit acetabular cup with polyethylene or ceramic insert and we have always used 36 mm femoral heads when allowed by the cup dimensions. We have used any size both of stems and cups without limitation due to the surgical approach. The mean age is 61.8 y.o., 324 females and 176 males. Obese patients, hip dysplasia Crowe 3 and 4 and post traumatic arthrosis are exclusion factors for the execution of this approach. If possible we have maintained the capsulo-tendinous less invasivity. The BMI is not an excluding factor because it's just the gluteus region that is an important factor to decide if to execute or not a less invasive approach. Analyzing our 500 cases we didn't have any case of malpositioning of the stem in varus or valgus (more than 5°) and considering acetabular cup we had the tendency to position it in valgus position (not more than 40°) in the first 20 cases. No leg discrepancy more than 1 cm were observed. Intra-operative blood loss have been reduced of about 30 % and 50% in the post-operative. All the patients were able to active hip mobilization within the first day after surgery with a mean range of motion of 0-70°. The patients were mobilized the first day after surgery and 80% of them were able to assisted walk within second day after surgery. The mean time of stay in hospital was 6.8 days. After 4 weeks 98% of the patients were able to walk without crutches. One case of deep infection were evaluated and then solved with surgical debridement; no wound dehiscence. We had 1 case of anterior hip dislocation in dysplastic arthrosis due to a technical mistake. In 1 case we had femoral nerve palsy, then solved, probably because of anterior retractor malpositioning. We had 5 cases of piriformis muscle contracture without sciatic nerve palsy, then solved. We think that for total hip replacement this conservative postero-lateral approach, thanks to capsule-tendinous modification we have adopted, could be considered an anatomical approach, which doesn't present more dislocation risks compared to other approaches to the hip also thanks to the introduction of 36 mm femoral head that gives more stability and proprioceptiveness. Besides this approach gives the possibility of a shorter rehabilitation as seen above and it could be consider optimal for total hip replacement

Background. Total Hip Arthroplasty (THA) using the Direct Anterior Approach (DAA) is a muscle sparing approach which promotes early mobilisation of patients. It is a technically challenging approach shown to have a high rate of complications, especially during the learning curve. Here we present the results of 157 cases of THA via a DAA on a standard theatre table, with a minimum of 6 months follow-up. Materials & Methods. The authors conducted a prospective study on a group of 149 consecutive patients undergoing 157 cementless primary THAs for coxarthrosis, 8 bilateral. The same surgical technique was used in all patients, performed by the senior author WLW at a single centre. The average age of the patients at time of surgery was 69 years, 78% were female and 57% were right sided. All implants were uncemented, with bearings being ceramic on ceramic or Ceramic on highly cross-linked polyethylene. Patients were assessed clinically and radiographically pre- and post-operatively at 6 weeks, 6 months, 1 and 2 years. Intra-operatively, navigation was used to guide cup position and assess offset and leg length. Results & Discussion. At the time of the latest follow-up, 1 patient had died of unrelated cause and 8 (5%) were lost to follow-up Clinically, the mean Harris Hip Score was 91 points with 88% reporting a good or excellent result, with 5% reporting moderate to severe pain. Radiographically all patients assessed had evidence of stable bony ingrowth. There was subsidence of 2–5mm in 9 stems (6%). Osteolysis was reported adjacent to one cup and one stem. There were no dislocations. The complication rate was 4.5%. This included 2 intra-operative femoral fractures, one a minor greater trochanteric fracture not requiring fixation, the other a calcar fracture treated at time of surgery. There were 3 femoral fractures occurring on average 4 weeks after surgery all requiring revision and one stem subsidence of 10mm following a heavy fall, subsequently requiring revision for leg length discrepancy. Other complications included one non-fatal PE, a haematoma that required evacuation. We report 20 (12%) episodes of lateral femoral cutaneous nerve palsy of any severity, most of which had or were resolving at the 6 month follow-up. Kaplan Mieir survival analysis was 97.2% at minimum 6 months. Patients mobilised day of surgery or day 1 post-op, and were discharged on average day 4 post-op. Neither the intra- or post-operative fractures could be attributed to the learning curve. Similarly episodes of stem subsidence and LFCN palsy occurred spread out over the 3 years of the study. This study supports the existing orthopaedic literature reporting the benefits of the DAA for THA with reduced soft tissue damage, reduced blood loss and early mobilisation with a low incidence of dislocation. Other authors however have reported a high incidence of complications attributing them to the early learning curve. This early study of DAA using a standard theatre table has identified that complications of fracture, stem subsidence and LFCN injury can occur at any time and bear no relationship to a learning curve

Sacroiliac joint (SIJ) fusion is a controversial yet last resort operative technique to address SIJ pain. The current study aims to determine the patient outcomes of SIJ fusions, in a single surgeon series utilising an anterior approach with 2 DC plates across the joint and iliac crest autograft. Retrospective case series involving 11 patients who had 13 SIJ fusions performed over an 8 year period (2002–2010). Patients were identified by electronic key word search from databases at Middlemore hospital and the private sector. Dictated clinic letters and operation notes were reviewed to obtain demographic data and outcomes data including complications. Postoperative radiology reports were reviewed to document radiographic fusion status. Telephone interviews were conducted to measure clinical outcome scores via the Majeed Pelvic Score and the 12-item Short-Form Health Survey (SF-12). 10 out of 11 patients (entailing 12 SIJ fusions) responded and participated in the study, equating to over 90% follow up. 2 cases were managed at Middlemore Hospital, with the remainder in the private sector. All cases but one had a ‘post-traumatic arthritis’ etiology. Diagnosis was made by CT guided local/steroid injection into the joint in conjunction with CT/bone scan/MRI imaging. The Majeed score improved markedly for 9 of 12 SIJ fusions (75%). 10 of 12 patients stated they would have the procedure again. 7 of 12 fusions (58%) had postoperative complications including blood loss, haematoma, nerve injury (including one case of permanent foot drop), non-union, infection of the joint/metal ware, hernia and urinary retention. 5 of 12 fusions (42%) experienced altered sensation over the lateral femoral cutaneous nerve distribution. All except one patient eventually had x-rays or CT scans postoperatively that reported radiographic fusion of the joint. In appropriately selected patients with SI joint arthrosis, 3/4 patients reported significant improvement in function and pain level after SIJ fusion. Chronic pain (from other sources) and major complications were a feature amongst those failing to benefit. Lateral femoral cutaneous nerve palsy has high incidence with the current operative technique

BACKGROUND. Our modified procedure for rotational acetabular osteotomy (RAO) aimed to reduce operative invasion of soft tissue and to minimize incision length. SURGICAL TECHNIQUE. A shortened skin incision (10–15 cm versus 20–30 cm in traditional RAO) is curved over greater trochanter and exposed by transtrochanteric approach. Medial gluteus muscle is retracted to expose the ilium without detachment from iliac crest. Similarly the rectus femoris muscle tendon was retracted, not excised, from the anterior inferior iliac spine. The lateral part of the osteotomized ilium is cut in lunate and trapezoid shape to form the bone graft instead of the outer cortical bone of the ilium. PATIENTS. We performed RAO on 66 patients (75 hips) using this modified procedure between 2000 and 2009. Follow-up rate was 95% (71/75 hips). Of 71 hips, 28 had early-stage, and 43 had advanced-stage osteoarthritis. Mean patient age was 39.7 years at time of surgery. Mean length of follow-up was 5.3 years. Clinical assessment was performed using the Merle d'Aubigne & Postel scores. Radiographically, the lateral center-edge (CE) angle, the Sharp angle and acetabular head index (AHI) were evaluated pre- and post-operatively. RESULTS. Mean CE angle, Sharp angle and AHI improved pre- to post-operatively from −1.3 degrees to 36.5 degrees (p<0.00001), 50.3 degrees to 39.4 degrees (p<0.00001), 54.0 % to 95.7 % (p<0.00001), respectively. Clinical hip scores at latest follow-up were significantly improved. No progression of osteoarthritis was seen in hips with early-stage osteoarthritis. Ten hips with advanced-stage osteoarthritis preoperatively had radiographic evidence of progression of osteoarthritis, and six of those were converted to total hip arthroplasty. Complications included two transient lateral femoral cutaneous nerve palsies and ectopic bone formation in 15 hips, one of which required excision 1.5 years post-RAO. Kaplan-Meier survivorship analysis, with decreased clinical scores from pre-operatively and radiographic signs of progression of osteoarthritis as the end point, predicted a 10-year survival rate of 100% for early-stage osteoarthritis hips and 72.1 % for advanced-stage osteoarthritis. CONCLUSIONS. Less invasive surgical procedure for RAO preserved function of hip abductor muscle and did not adversely influence on clinical or radiographic outcome