Comparison of the minimally invasive and ilioinguinal approaches for periacetabular osteotomy: 263 single-surgeon procedures in well-defined study groups

The Impact of Epidural Analgesia on Immobility and extended Hospital Stay After Periacetabular Osteotomy

AIMS

Early mobilisation after periacetabular osteotomy (PAO) represents an important goal after surgery. The purpose of this study was to determine whether the use of epidural aznalgesia (EA) is associated with prolonged immobility and an increased length of stay (LOS) after PAO surgery.

METHODS

From January 2022 to July 2023, the study included a cohort of 150 PAO procedures all performed by the same surgeon (SSA). Patients were categorized into two distinct groups: those who received epidural analgesia (EA) (79 PAOs) and those who did not receive EA (71 PAOs). "Ready for discharge" was defined as the ability to ascend and descend a standardized flight of stairs independently. Multivariable linear regression was used to identify additional factors influencing LOS after PAO.

RESULTS

Patients in the EA group were ready for discharge 5.95 ± 2.09 days after surgery which was significantly longer than in the No EA group´s average of 4.18 days ± 2.5, (p < 0.001). While the reduction in the number of patients experiencing pulmonary embolism in the No EA group did not reach statistical significance, it still demonstrated a relevant decrease from two patients within the EA group (2.53%) to 0 (0%) in the No EA group. The active engagement of the surgeon in mobilising patients led to a substantial reduction in LOS, decreasing it from 5.81 ± 2.18 days to 2.2 ± 0.77 days (p < 0.001). Multivariable analysis revealed five independent factors influencing the LOS following PAO which included absence of EA, surgeon-led mobilisation within 24 h after surgery, postoperative hemoglobin levels, BMI, and prior experience with PAO surgery on the contralateral side.

CONCLUSIONS

Opting against the use of EA in patients undergoing PAO is advisable, as it will result in extended postoperative immobility and the associated risks. Additionally, the active participation of the surgeon in the mobilisation process is strongly recommended.

The incidence of subsequent hip arthroscopy after rectus-sparing periacetabular osteotomy

Aims

Periacetabular osteotomy (PAO) is the preferred treatment for symptomatic acetabular dysplasia in adolescents and young adults. There remains a lack of consensus regarding whether intra-articular procedures such as labral repair or improvement of femoral offset should be performed at the time of PAO or addressed subsequent to PAO if symptoms warrant. The purpose was to determine the rate of subsequent hip arthroscopy (HA) in a contemporary cohort of patients, who underwent PAO in isolation without any intra-articular procedures.

Methods

From June 2012 to March 2022, 349 rectus-sparing PAOs were performed and followed for a minimum of one year (mean 6.2 years (1 to 11)). The mean age was 24 years (14 to 46) and 88.8% were female (n = 310). Patients were evaluated at final follow-up for patient-reported outcome measures (PROMs). Clinical records were reviewed for complications or subsequent surgery. Radiographs were reviewed for the following acetabular parameters: lateral centre-edge angle, anterior centre-edge angle, acetabular index, and the alpha-angle (AA). Patients were cross-referenced from the two largest hospital systems in our area to determine if subsequent HA was performed. Descriptive statistics were used to analyze risk factors for HA.

Results

A total of 16 hips (15 patients; 4.6%) underwent subsequent HA with labral repair and femoral osteochondroplasty, the most common interventions. For those with a minimum of two years of follow-up, 5.3% (n = 14) underwent subsequent HA. No hips underwent total hip arthroplasty and one revision PAO was performed. Overall, 17 hips (4.9%) experienced a complication and 99 (26.9%) underwent hardware removal. All PROMs improved significantly postoperatively. Radiologically, 80% of hips (n = 279) reached the goal for acetabular correction (77% for acetbular index and 93% for LCEA), with no significant differences between those who underwent subsequent HA and those who did not.

Conclusion

Rectus-sparing PAO is associated with a low rate of subsequent HA for intra-articular pathology at a mean of 6.2 years' follow-up (1 to 11). Acetabular correction alone may be sufficient as the primary intervention for the majority of patients with symptomatic acetabular dysplasia.

Hip survivorship following the Bernese periacetabular osteotomy for the treatment of acetabular dysplasia: A systematic review and meta-analysis

INTRODUCTION

The Bernese periacetabular osteotomy (PAO) is a popular joint-preservation technique aimed at addressing the structural and biomechanical abnormalities associated with acetabular dysplasia. However, the prognostic factors and long-term survivorship of the native hip, with failure defined as conversion to total hip arthroplasty (THA), is poorly understood. Our study aims to address the following: (1) What is the estimated duration of survival of the native hip post-PAO, (2) What are some prognostic factors of functional outcome and (3) What is the complication rate and complications associated with PAO.

HYPOTHESIS

The Bernese PAO is able to result in favourable mid- to long-term outcomes conditional on a stringent patient selection criteria.

MATERIALS AND METHODS

A systematic review was performed using the PRISMA guidelines. All studies that reported on the outcomes of isolated Bernese PAO for the treatment of acetabular dysplasia were included.

RESULTS

A total of 24 studies (3471 patients, 3655 hips) were included at a mean follow-up duration of 54.2months (range: 1-336months). In total, 208 hips (6.03%; 95% CI: 5.25-6.94%) converted to THA at a mean duration of 4.71years (range: 1-240months). Univariate analysis identified advanced age beyond a follow-up duration of 6years (p=0.001) and preoperative Tönnis grade 2 and above (p<0.001) to be the most significant negative prognostic factors. Beyond a follow-up duration of 2years, intraoperative fluoroscopy proved to be a significant positive prognostic factor (p<0.001). Indications for PAO, obesity and gender were not found to be significant predictors of failure. Our study found the complication rate to be 23.5% (95% CI: 21.6-25.6%). The most common complications detailed are transient lateral femoral cutaneous nerve dysesthesia (8.24%; 95% CI: 7.02-9.65%), stress fracture (5.28%; 95% CI: 4.31-6.89%) and the delayed union, non-union or pseudoarthrosis of the ramus not necessitating surgical correction (3.73%, 95% CI: 2.93-4.75%).

DISCUSSION

PAO alters the natural history of the dysplastic hip with a 10- and 20-year survivorship of approximately 75.9% and 36.5% of patients respectively. The ideal patient should be below 40years old, with a preoperative Tönnis grade of 0 or 1. Intraoperative fluoroscopy is able to guide a better precision when re-orientating the acetabulum.

LEVEL OF EVIDENCE

IV; systematic review and meta-analysis.

[Minimally invasive periacetabular osteotomy for adult hip dysplasia]

OBJECTIVE

Performance of a periacetabular osteotomy (PAO) using a minimally invasive approach for three-dimensional correction of the acetabular position.

INDICATIONS

Symptomatic developmental dysplasia of the hip in adolescents and adults.

CONTRAINDICATIONS

Advanced osteoarthritis of the hip, incongruence of the hip joint surfaces.

SURGICAL TECHNIQUE

A periacetabular osteotomy is performed via a minimally invasive approach.

RESULTS

In total, 39 patients were followed up for 3.5 (3-4.5) years. The lateral center-edge angle of Wiberg increased significantly from 16.1° (7-24°) to 30.5° (25-37°) (p < 0.0001), the acetabular index changed from 13.2° (2-25.3°) to 2.8° (-3-13°; p < 0.0001). Mean duration of surgery was 88 (57-142) minutes. No major complications occurred.

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

Background

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

Method and materials

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

Results

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

Conclusion

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

A New Rectus and Sartorius Sparing Approach for Periacetabular Osteotomy in Patients with Developmental Dysplasia of the Hip

Background: periacetabular osteotomy (PAO) is known as the gold standard surgical treatment in young adults with symptomatic hip dysplasia. With the aim of reducing soft tissue trauma, we developed a new rectus and sartorius sparing (RASS) approach. We hypothesized that this new PAO technique was equal regarding acetabular reorientation, complication rate, and short-term clinical outcome parameters, compared to our conventional, rectus sparing (RS) approach. Patients and Methods: we retrospectively assessed all PAO procedures performed by a single surgeon between 2016 and 2019 (n = 239 hips in 217 patients). The cases in which the new RASS technique were used (n = 48) were compared to the RS cases for acetabular orientation parameters, surgical time, perioperative reduction of hemoglobin level, and length of hospital stay (LOHS). Inclusion criteria were a lateral center-edge angle (LCEA) <25° and osteoarthritis Tönnis grade ≤1. Patients with acetabular retroversion or additional femoral osteotomy were excluded. Results: the mean patient age at the time of surgery was 29 years (14 to 50, SD ± 8.5). Females accounted for 79.5% in this series. The mean preoperative LCEA were 16° (7 to 24°, SD ± 4.4) and 15° (0 to 23°, SD ± 6) in the RASS and the RS group, respectively (p = 0.96). The mean preoperative acetabular index (AI) angles were 14° (2 to 25°, SD ± 4) and 14° (7 to 29°, SD ± 4.3), respectively (p = 0.67). The mean postoperative LCEA were significantly improved to 31° (25 to 37°, SD ± 3.5, p < 0.001) and 30.2° (20 to 38°, SD ± 4, p < 0.001), respectively. The mean postoperative AI angles improved to 2.8° (−3 to 13°, SD ± 3.3, p < 0.001) and 3° (−2 to 15°, SD ± 3.3, p < 0.001), respectively. There were no significant differences between the RASS and the RS group for surgical time, perioperative reduction in hemoglobin level, and LOHS. No blood transfusions were necessary perioperatively in either group. No major perioperative complication occurred in either group. We observed one surgical site infection (SSI) requiring superficial debridement in the RS group. Conclusion: the RASS approach for PAO showed to be a safe procedure with equivalent acetabular reorientation and equivalent clinical outcome parameters compared to the RS approach. Additionally, patients have fewer postoperative restrictions in mobilization with the RASS approach.

Does hip preservation surgery prevent arthroplasty? Quantifying the rate of conversion to arthroplasty following hip preservation surgery

Hip arthroscopic surgery for femoroacetabular impingement and periacetabular osteotomy (PAO) for dysplasia is the most commonly used contemporary treatment for these conditions and has been shown to provide pain relief and restore function. What is less understood and perhaps of more interest to health economists, is the role of these procedures in preserving the hip joint and avoiding hip arthroplasty. The aim of this systematic review was to determine whether hip joint preservation surgery, indeed, preserves the hip joint by looking at conversion rates to total hip arthroplasty (THA). Two separate searches were undertaken, using PRISMA guidelines and utilizing PubMed and Open Athens search engines, identifying manuscripts that looked at conversion to THA following either hip arthroscopy (HA) or PAO. When considering HA, we found 64 eligible papers. Out of these studies, there were 59 430 hips with 5627 undergoing conversion to THA (9.47% [95% CI 9.23–9.71%]) with a mean conversion time of 24.42 months. Regarding PAO, there were 46 eligible papers including 4862 patients who underwent PAO with subsequent conversion to THA in 404 patients (8.31% [95% CI 7.54–9.12%]). with a mean conversion time of 70.11 months. Certain features were associated with increased conversion rates, including increasing age, worsening arthritis and joint space <2 mm. This study demonstrates that the mean conversion rates to be <10% for HA and PAO, during the mean follow-up periods of included manuscripts. Joint preserving surgery appears to defer or at least delay the need for THA.

Periacetabular osteotomy for hip dysplasia treatment through a mini-invasive technique. Our results at mid-term in 131 cases

BACKGROUND AND OBJECTIVE

Periacetabular osteotomy (PAO) is an accepted and worldwide technique recognized for residual dysplasia treatment and even in unstable hips with limited acetabular coverage. The aim of this study is to analyse the functional, radiological and complication results in patients treated with mini-invasive PAO.

MATERIAL AND METHODS

We performed a retrospective study in which we analysed 131 cases undergoing mini-invasive PAO at our centre. The degree of joint degeneration was evaluated with Tönnis scale, Wiberg angle, acetabular index (AI), anterior coverage angle (AC), joint space, complications and functional outcome with the Non-Arthritic Hip Score (NAHS) were analysed preoperatively and at the end of follow-up.

RESULTS

The average age was 32.3±9.5 (SD) years, 102 (77.9%) were female and 29 (22.1%) were male. 7.7±2.8 (SD) years follow up. The radiological parameters improved between the pre-surgical phase and the end of follow-up, Wiberg angle+18.5° (18.3° versus 36.8°, 95% CI 17.3 to 19.7), AC angle+13.5° (26.2° versus 39.7°, 95%CI 11.6 to 15.4) and the AI -11.1° (19.5° versus 8.4°; 95%CI -12.1 to -10,1). In addition, the functional results, with the NAHS scale, improved+31.3 points (60.7 pre-surgical versus 92 at the end of follow-up, 95% CI 28.7 to 33.8). The most common complication was transient lateral femoral cutaneous nerve hypoaesthesia in 10 cases (7%).

CONCLUSION

The mini-invasive PAO approach is a reproducible technique, it allows restoration of acetabular coverage and provides an improvement in functional scales as confirmed by our series.

Pose Estimation of Periacetabular Osteotomy Fragments With Intraoperative X-Ray Navigation

OBJECTIVE

State-of-the-art navigation systems for pelvic osteotomies use optical systems with external fiducials. In this paper, we propose the use of X-ray navigation for pose estimation of periacetabular fragments without fiducials.

METHODS

A two-dimensional/three-dimensional (2-D/3-D) registration pipeline was developed to recover fragment pose. This pipeline was tested through an extensive simulation study and six cadaveric surgeries. Using osteotomy boundaries in the fluoroscopic images, the preoperative plan was refined to more accurately match the intraoperative shape.

RESULTS

In simulation, average fragment pose errors were 1.3 ° /1.7 mm when the planned fragment matched the intraoperative fragment, 2.2 ° /2.1 mm when the plan was not updated to match the true shape, and 1.9 ° /2.0 mm when the fragment shape was intraoperatively estimated. In cadaver experiments, the average pose errors were 2.2  ° /2.2 mm, 3.8 ° /2.5 mm, and 3.5  ° /2.2 mm when registering with the actual fragment shape, a preoperative plan, and an intraoperatively refined plan, respectively. Average errors of the lateral center edge angle were less than 2 ° for all fragment shapes in simulation and cadaver experiments.

CONCLUSION

The proposed pipeline is capable of accurately reporting femoral head coverage within a range clinically identified for long-term joint survivability.

SIGNIFICANCE

Human interpretation of fragment pose is challenging and usually restricted to rotation about a single anatomical axis. The proposed pipeline provides an intraoperative estimate of rigid pose with respect to all anatomical axes, is compatible with minimally invasive incisions, and has no dependence on external fiducials.

Complications and outcome after periacetabular osteotomy - influence of surgical approach

BACKGROUND

Bernese periacetabular osteotomy (PAO) was introduced by Ganz as a novel surgical technique for hip dysplasia with a congruent hip to reorient the acetabulum in skeletally mature patients. The PAO through a modified Smith-Petersen (Iliofemoral) approach, has been subject to many modifications in order to avoid complications and to minimise risks for failure.

AIM

The aim of this review was to report on the complication rates, functional and radiological outcomes in relation to surgical approaches.

METHODS

A search of NICE healthcare database advanced search, was conducted from the year of inception to May 2018. We included studies that reported complications of PAO. Data extracted from case series was analysed to detect the incidence of complications, relation to surgical approach and temporal trend of complications.

RESULTS

40 studies including 4070 hips with a mean age of 29 years and a mean follow-up of 52.8 month, were analysed. Outcome measures demonstrated good to excellent outcome in 82%. Higher rates of LFCN and sciatic nerve injuries were found to be associated with the ilioinguinal and the 2-incision approach. Minimally invasive (MIS) modified Smith-Petersen (MSP), minimally invasive trans-sartorial and trans-trochanteric approaches were not reported to be associated with any major wound complications. Radiological correction achieved with a mean improvement in acetabular inclination of 17.90 (range 4.5-40), anterior centre-edge correction 25.40 (range 10-51), lateral centre-edge correction 23.30 (range 15-44.6) and medial translation of 6 mm (range 3.2-10).

CONCLUSIONS

The complication rates seem to be lower in this current review (7%) as compared to the previous review performed by Clohisy et al. (6-37%). The MIS trans-sartorial/MIS MSP and intertrochanteric approaches are associated with an even reduced complications rates. This review enables favouring the minimally invasive approaches with regard to reducing nerve injury and wound complications.

Anatomical variants of the rectus femoris motor innervation

Adult periacetabular osteotomy (PAO) was originally performed through the classic Smith-Petersen approach for optimal operative visibility and acetabular fragment correction. Evolution towards an abductor-sparing technique significantly lowered the post-operative morbidity. The rectus-sparing approach represents a step further, but the innervation of the rectus femoris is theoretically more at risk. Although the topographic anatomy of the femoral nerve has been well described, it was never studied with specificity to surgical landmarks. The femoral nerve’s spatial relation with the anterior-inferior iliac spine (AIIS) and the amount of possible dissection in the rectus femoris and iliopsoas interval is uncertain. Seven formalin-preserved human cadaveric specimens without history of inguinal injury or surgery were dissected using the distal limb of an iliofemoral approach. The level of entry of motor innervation was measured and number of branches to the rectus femoris was noted. The average longitudinal distance from the AIIS to the first motor nerve to the rectus femoris was 8.6 ± 1.4 cm. The number of branches varied between 1 and 4 with the most common innervation pattern being composed of two segments. Dissection medial to the rectus femoris should not be carried out further than 7 cm distal to the AIIS and stretching of that interval during surgical exposure should be done cautiously. The clinical efficiency of the rectus-sparing approach should be studied further in order to confirm its advantage over the classic direct anterior approach. The study provides a better understanding of the localization and the anatomical variations of the structures encountered at the level of and below the AIIS. It also assesses the relative risk of denervation of the rectus femoris during PAO through the rectus-sparing approach. The authors recommend that the dissection medial to the rectus femoris should be carried out no further than 7 cm distal to the AIIS and stretching of that interval during surgical exposure should be done cautiously.

Curved periacetabular osteotomy via a novel intermuscular approach between the sartorius and iliac muscles

INTRODUCTION

Herein, we describe and evaluate a curved periacetabular osteotomy (CPO) via an intermuscular approach (IM-CPO) between the sartorius and iliac muscles.

METHODS

Between January 2009 and January 2016, IM-CPO was performed in 17 joints (16 patients), and a traditional CPO was performed in 17 joints. The length of incision at wound closure, operative time, intraoperative blood loss, serum creatinine kinase (CK) level the day after surgery, correctional angle, walking ability assessed using the gait items of the Harris Hip Score (at 3 and 6 months after surgery), and perioperative complications were evaluated. Group differences were assessed using t-tests.

RESULTS

The IM-CPO and CPO groups did not differ in the mean operative time (130 minutes and 124 minutes, respectively), mean serum CK the day after surgery (349 IU/L and 425 IU/L, respectively), or mean correctional angle (24.9° and 24.6°, respectively). The mean incision length was significantly shorter in the IM-CPO group (8.3 cm) compared to that in the CPO group (9.5 cm). The mean walking ability was significantly higher in the IM-CPO group (24.2 points) compared to that in the CPO group (20.9 points) at 3 months after surgery, but not at 6 months after surgery (26.4 points and 24.9 points, respectively). No serious complications were observed in either group.

CONCLUSION

In addition to demonstrating a similarly satisfactory correctional angle, IM-CPO is anticipated to enable early weight-bearing and recovery of walking ability. Thus, IM-CPO is considered a superior surgical technique.

What level of pain reduction can be expected up to two years after periacetabular osteotomy? A prospective cohort study of 146 patients

Periacetabular osteotomy (PAO) corrects underlying anatomical anomalies, reduces pain and may postpone or even prevent osteoarthritis onset in patients with symptomatic acetabular dysplasia. Current evidence is based on immediate post-operative pain levels, but knowledge on pain levels in the period after PAO is scarce, and the association between pain score and acetabular angles at PAO is unknown. This study had two aims. First, we studied pain level and patient-reported outcome scores pre- and postoperatively; second, we analysed the association between acetabular angles and pain level. From our database, 426 patients operated from June 2012 to November 2015 were analysed; 127 were excluded. Patients were invited to complete standardized questionnaires preoperatively and postoperatively at 6 and 24 months. Pain was measured using visual analogue scale (VAS). Multiple regression analysis was used to investigate the association between change in centre edge (CE) and acetabular index (AI) angle and pre/postoperative pain levels. Mean (standard deviation, SD) VAS pain at rest before surgery and at the 6- and 24-month follow-up were 35 (24), 14 (20) and 14 (19), respectively. Mean (SD) VAS pain at activity were 69 (22), 41 (29) and 41 (30), respectively. Both VAS pain at rest and at activity fell from the preoperative level to 6 months post-surgery with no further change at 24 months. Patients reported significant improvement in outcomes after 6 months and no further change at the 24-month follow-up. There was no significant association between change in CE/AI angles and VAS pain, either during rest or activity.

[Development of hip preservation in treating adult hip dysplasia]

During the past decades, the field of hip preservation in China has achieved great improvements. Theoretically, the blood supply of the femoral head and the acetabulum along with the mechanism of early-stage hip osteoarthritis has been gradually cleared. The knowledge and application of the periacetabular osteotomy, surgical hip dislocation, and hip arthroscopy has been vigorously promoted. Improved understanding of the mechanism, pathology, and prevention protocols of the secondary hip dysplasia have been obtained, despite the fact that lack of awareness of some mechanism and detail, for example, hip instability or borderline dysplasia, etc. On the basis of summing up those clinical progress, this article further elaborated the historical development of hip preservation through the review of several traditional treatment, and made objective assessment about the follow-up, evaluation, minimally invasive surgery, and individualized treatment newly reported.

Minimally invasive periacetabular osteotomy using a modified Smith-Petersen approach: technique and early outcomes

AIMS

Periacetabular osteotomy is an effective way of treating symptomatic hip dysplasia. We describe a new minimally invasive technique using a modification of the Smith-Peterson approach. We performed a prospective, longitudinal cohort study to assess for any compromise in acetabular correction when using this approach, and to see if the procedure would have a higher complication rate than that quoted in the literature for other approaches. We also assessed for any improvement in functional outcome.

PATIENTS AND METHODS

From 168 consecutive patients (189 hips) who underwent acetabular correction between March 2010 and March 2013 we excluded those who had undergone previous pelvic surgery for DDH and those being treated for acetabular retroversion. The remaining 151 patients (15 men, 136 women) (166 hips) had a mean age of 32 years (15 to 56) and the mean duration of follow-up was 2.8 years (1.2 to 4.5). In all 90% of cases were Tönnis grade 0 or 1. Functional outcomes were assessed using the Non Arthritic Hip Score (NAHS), University of California, Los Angeles (UCLA) and Tegner activity scores.

RESULTS

The mean pre-operative lateral centre-edge angle was 14.2° (-5° to 30°) and the mean acetabular index was 18.4° (4° to 40°). Post-operatively these were 31° (18° to 46°) and 3° (-7° to 29°), respectively, a significant improvement in both (p < 0.001). Allogenic blood transfusion was required in two patients (1.2%). There were no major nerve or vascular complications, and no wound infections. At the time of last follow-up, we noted a significant improvement in functional outcome scores: UCLA improved by 2.31 points, Tegner improved by 1.08 points, and the NAHS improved by 25.4 points (p < 0.001 for each). Hypermobility and longer duration of surgery were significant negative predictors for a good post-operative UCLA score, while residual retroversion was a positive predictor of post-operative UCLA score.

CONCLUSION

We have found this approach to be safe and effective, facilitating early recovery from surgery. Cite this article: Bone Joint J 2017;99-B:22-8.

Factors That Predict Blood Loss After Bernese Periacetabular Osteotomy

Although strategies to reduce bleeding and avoid allogeneic transfusion have been described, there is controversy about the factors associated with blood loss after Bernese periacetabular osteotomy. This study was conducted to determine risk factors for postoperative blood loss. After institutional review board approval was obtained, a retrospective review was conducted of 41 young patients who underwent periacetabular osteotomy for symptomatic acetabular dysplasia over a 3-year period. Of these patients, two-thirds donated blood before surgery. A Cell Saver Elite autotransfusion system (Haemonetics, Braintree, Massachusetts) was used intraoperatively in all cases. Hemoglobin and hematocrit were obtained before surgery and during the hospital stay. The primary outcome variable was the percentage of total blood volume lost during surgery. Univariate analysis was performed to test the association between potential predictors of blood volume loss. Candidate variables that were significant at alpha=0.15 were tested with multivariate analysis. The average percentage of blood volume lost during surgery was 30.3% (95% confidence interval, 25.1%-35.5%). Univariate analysis showed that operative time, arthrotomy, femoral head-neck osteochondroplasty, labral procedure, male sex, and age were prognostic factors associated with increased blood volume loss. However, operative time (average, 294.6 minutes; range, 204-444 minutes) was the only independent predictor of increased blood loss in the final model. Additional procedures, such as femoral head-neck osteochondroplasty and labral repair or debridement performed through an anterior hip arthrotomy at the time of periacetabular osteotomy, were associated with increased operative time. The findings suggest that all patients undergoing periacetabular osteotomy, including those having concomitant procedures, may benefit from pre- and intraoperative strategies to conserve blood and avoid allogeneic transfusion. [Orthopedics. 2016; 39(6):e1147-e1153.].

Intravenous Tranexamic Acid Decreases Allogeneic Transfusion Requirements in Periacetabular Osteotomy

Bernese (Ganz) periacetabular osteotomy is associated with significant blood loss and the need for perioperative transfusion. Tranexamic acid decreases blood loss and minimizes transfusion rates in total joint arthroplasty. However, no reports have described its use in patients undergoing Bernese periacetabular osteotomy. This study reports the use of intravenous tranexamic acid in these patients. The study included 137 patients (150 hips) who underwent isolated periacetabular osteotomy at a single institution between 2003 and 2014. Of these, 68 patients (75 hips) received intravenous tranexamic acid 1 g at the time of incision and 1 g at the time of closure. A group of 69 patients (75 hips) served as control subjects who underwent periacetabular osteotomy without administration of intravenous tranexamic acid. Thromboembolic disease was defined as deep venous thrombosis or pulmonary embolism occurring within 6 weeks of surgery. Outcomes measured included transfusion requirements, pre- and postoperative hemoglobin values, operative times, and thromboembolic disease rates. Aspirin was used as the thromboembolic prophylactic regimen in 95% of patients. The rate of allogeneic transfusion was 0 in the tranexamic acid group compared with 21% in the control group (P=.0001). No significant difference was found in the autologous cell salvage requirement (.96 vs 1.01; P=.43) or the thromboembolic disease rate between the tranexamic acid group and the control group (2.67% vs 1.33%; P=.31). The use of intravenous tranexamic acid led to a decreased transfusion requirement with no increased risk of thromboembolic disease in this contemporary cohort of patients undergoing periacetabular osteotomy.

Endoscopic hip osteotomies: less invasive approaches to peri-acetabular, proximal femoral and pubic symphyseal procedures

Beyond the recent expansion of extra-articular hip arthroscopy into the peri-trochanteric and subgluteal space, this instructional course lecture introduces three innovative procedures: endoscopy-assisted periacetabular osteotomy, closed derotational proximal femoral osteotomy and endoscopic pubic symphysectomy. Supportive rationale, evolving indications, key surgical techniques and emerging outcomes are presented for these innovative less invasive procedures.

Association of Epsilon-Aminocaproic Acid With Blood Loss and Risk of Transfusion After Periacetabular Osteotomy: A Retrospective Cohort Study

BACKGROUND

Periacetabular osteotomy (PAO) reorients the acetabular cartilage through a complex series of pelvic osteotomies, which risks significant blood loss often necessitating blood transfusion. Therefore, it is important to identify effective strategies to manage blood loss and decrease morbidity after PAO. The purpose of this study was to determine the association of epsilon-aminocaproic acid (EACA), an antifibrinolytic agent, with blood loss from PAO.

METHODS

Ninety-three patients out of 110 consecutive patients that underwent unilateral PAO for acetabular dysplasia met inclusion criteria. Fifty patients received EACA intraoperatively. Demographics, autologous blood predonation, anesthetic type, intraoperative estimated blood loss (EBL), cell-saver utilization, and transfusions were recorded. Total blood loss was calculated. Two-sample t-test and chi-square or Fisher's exact test were used as appropriate. The associations between EACA administration and calculated EBL, cell-saver utilization, intraoperative EBL, and maximum difference in postoperative hemoglobin were assessed via multiple regression, adjusting for confounders. Post hoc power analysis demonstrated sufficient power to detect a 250-mL difference in calculated EBL between groups. Alpha level was 0.05 for all tests.

RESULTS

No demographic differences existed between groups. Mean blood loss and allogeneic transfusion rates were not statistically significant between groups (P = .093 and .170, respectively). There were no differences in cell-saver utilization, intraoperative EBL, and/or postoperative hemoglobin. There was a higher rate of autologous blood utilization in the group not receiving EACA because of a clinical practice change.

CONCLUSIONS

EACA administration was not associated with a statistically significant reduction in blood loss or allogeneic transfusion in patients undergoing PAO.

Periacetabular osteotomy through the pararectus approach: technical feasibility and control of fragment mobility by a validated surgical navigation system in a cadaver experiment

PURPOSE

The pararectus approach has been validated for managing acetabular fractures. We hypothesised it might be an alternative approach for performing periacetabular osteotomy (PAO).

METHODS

Using four cadaver specimens, we randomly performed PAO through either the pararectus or a modified Smith-Petersen (SP) approach. We assessed technical feasibility and safety. Furthermore, we controlled fragment mobility using a surgical navigation system and compared mobility between approaches. The navigation system's accuracy was tested by cross-examination with validated preoperative planning software.

RESULTS

The pararectus approach is technically feasible, allowing for adequate exposure, safe osteotomies and excellent control of structures at risk. Fragment mobility is equal to that achieved through the SP approach. Validation of these measurements yielded a mean difference of less <1 mm without statistical significance.

CONCLUSION

Experimental data suggests the pararectus approach might be an alternative approach for performing PAO. Clinical validation is necessary to confirm these promising preliminary results.

Clinical and radiological outcome after periacetabular osteotomy: a cross-sectional study of 127 hips operated on from 1999-2008

PURPOSE

Few papers have described results after periacetabular osteotomy (PAO) and risk factors for conversion to total hip arthroplasty (THA). The aim of the present paper was to analyse clinical and radiographic outcome, survival of the hip joint and risk factors of early conversion to THA in patients with PAO.

BASIC PROCEDURES

In the period 1999-2008, 93 patients (127 hips, median patient age 31, range 13-49 years) were operated on with PAO. Median follow-up was 7 (SD 2.1) years. Analyses of clinical and radiographic examinations, including WOMAC, were performed. Osteoarthritis was measured using Tönnis grade. Survival was assessed by the Kaplan-Meier method and predictors of conversion to THA were calculated using Cox regression analysis with THA as defined endpoint.

MAIN FINDINGS

Centre-edge angle improved significantly with a mean of 8.7 (95% CI: 7.1; 10.3) preoperatively to a mean of 24.6 (95% CI: 22.6; 26.6) at follow-up. Likewise the acetabular roof obliquity angle improved significantly with a mean of 21.2 (95% CI: 19.7; 22.6) preoperatively to 8.7 (95% CI: 7.1; 10.4) at follow-up. Eleven out of 127 hips had conversion to THA. The 11.7 years cumulated hip joint survival rate was 85% (95% CI: 0.753; 0.945). Significant predictors of converting to THA were preoperative high grade of OA and postoperative high degree of acetabular roof obliquity angle. An improvement was found in Harris Hip Score pain score after receiving a PAO (p = 0.01).

CONCLUSIONS

Our results, with almost 12 years survival data, are comparable with the literature. PAO is considered as an effective treatment for young adults with painful hip dysplasia, especially when preoperative criteria for conversion to THA are highlighted.

The incidence of stress fracture following peri-acetabular osteotomy: an under-reported complication

Stress fractures occurring in the pubis and ischium after peri-acetabular osteotomy (PAO) are not well recognised, with a reported incidence of 2% to 3%. The purpose of this study was to analyse the incidence of stress fracture after Bernese PAO under the care of two high-volume surgeons. The study included 359 patients (48 men, 311 women) operated on at a mean age of 31.1 years (15 to 56), with a mean follow-up of 26 months (6 to 64). Complete follow-up radiographs were available for 348 patients, 64 of whom (18.4%) developed a stress fracture of the inferior pubic ramus, which was noted at a mean of 9.1 weeks (5 to 55) after surgery. Most (58; 91%) healed. In 40 of the patients with a stress fracture (62.5%), pubic nonunion also occurred. Those with a stress fracture were significantly older (mean 33.9 years (16 to 50) vs 30.5 years (15 to 56), p = 0.002) and had significantly more mean pre-operative deformity: mean centre-edge angle (9.8° (-9.5 to 35) vs 12.4° (-33 to 28), p = 0.04) and mean Tönnis angle (22.8° (0 to 45) vs 18.7° (-2 to 38), p < 0.001). The pubic nonunion rate was significantly higher in those with a stress fracture (62.5% vs 7%, p < 0.001), with regression analysis revealing that these patients had 11.8 times higher risk than those without nonunion.

Preservation of the rectus femoris origin during periacetabular osteotomy does not compromise acetabular reorientation

BACKGROUND

The early recovery period after periacetabular osteotomy (PAO) can be limited by pain and activity restrictions. Modifications of the Bernese PAO, including sparing the rectus tendon and discontinuing routine arthrotomy, may accelerate early postoperative recovery compared with the standard approach.

QUESTIONS/PURPOSES

Does a modified approach for PAO (1) lead to improved pain control immediately after surgery; (2) lead to improved ambulation during the hospital stay; (3) lead to shorter stays, less blood loss, and shorter surgical times; and (4) compromise acetabular correction?

METHODS

We retrospectively reviewed all 75 patients who underwent PAO for developmental dysplasia of the hip between August 2009 and May 2013. The control group included 44 consecutive patients who underwent a standard Bernese PAO with rectus takedown (RT). The study group consisted of 31 consecutive patients who underwent PAO using a modified rectus-sparing (RS) approach without routine arthrotomy. The groups were similar in age, body mass index, and American Society of Anesthesiologists score, but the RT group was comprised of a greater percentage of men than the RS group. Outcome variables were collected from patient charts and included inpatient pain, inpatient ambulation as well as length of stay, estimated blood loss, surgical time, and postoperative radiographic measurements. Cohen's f(2) was used to calculate the effect size in the regression analysis and effects were considered small for values<0.15, moderate for 0.15 to 0.34, and large for values>0.35.

RESULTS

Patients who underwent PAO with a RS approach had less overall pain (RT median 4 versus RS median 2); however, the difference may not have been perceptible to the typical patient (p=0.001, f2=0.059). Patients treated with the RS approach ambulated similar distances during the hospital stay with a median 11 feet (interquartile range [IQR], 0-72.5) for the RT group and a median 30 feet (IQR, 0-100) for the RS group (p=0.215, f2=0.095). Patients in the RT group had a median length of stay of 4 days (IQR, 4-5) compared with a median 3 days (IQR, 3-4) in the RS group (p<0.001). The median estimated blood loss was greater (p=0.010) in the RT group (median, 500 mL; IQR, 350-700) versus the RS group (median, 300; IQR, 250-500). The median surgical time was longer (p<0.001) in patients undergoing PAO with the RT approach (median, 159.5 minutes; IQR, 145.5-177) compared with the RS approach (median, 103 minutes; IQR, 75-114). Acetabular reorientation based on postoperative radiographs was not compromised by the modified approach.

CONCLUSIONS

The approach modification was straightforward to implement in all patients and did not compromise acetabular fragment mobilization or final positioning. Two of the three key variables that the approach might have influenced-pain and length of stay-were below the minimum clinically important difference and different by only a fraction of a day, respectively. The difference in ambulation was of only modest clinical importance. More definitive evidence for clinical superiority in terms of pain, ambulation, and return of muscle function will likely require more sophisticated instruments such as gait analysis, muscle strength testing, and longer-term outcome studies with sensitive instruments.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Periacetabular osteotomy: sporting, social and sexual activity 9-12 years post surgery

Hip joint survivorship and functional outcome are traditional outcome measures applied after periacetabular osteotomy (PAO). Younger adults however have greater demands and expectations on the function of their hip joints and these demands are not expressed using traditional outcome assessment tools. The main purpose of this study was to explore alternative functional and quality of life measure after PAO.A cross sectional survey of preserved hip joints following PAO was performed. Fifty-two patients (68 hips), mean age 41 years (range 24-67), returned a questionnaire examining satisfaction, willingness to repeat surgery, quality of life, abilities in social activities, sports and sex-life, pain, limp, and stability of the hip.Median satisfaction was 5 (range 1-5) and 44 of 49 patients were willing to repeat surgery. Significant improvements were seen in quality of life, ability to do sports, participate in social activities and sex-life (p values <0.001) (although sex-life for males (p = 0.102)). Traditional outcomes (pain, stability and limp) showed significant improvements (p<0.001). Lasting improvements in patients' sex life, social life and ability to do sports nine to 12 years following PAO were reported. Such factors are important measures of outcome in a younger adult cohort.

The Bernese periacetabular osteotomy: is transection of the rectus femoris tendon essential?

BACKGROUND

The Bernese periacetabular osteotomy (PAO) traditionally is performed using the iliofemoral or the ilioinguinal approach with transection of the rectus femoris tendon attachments. Although a rectus-preserving approach has been developed, there is limited direct comparison data regarding the surgical safety, radiographic correction, and improvement in hip pain and function between the rectus-preserving and the classic approaches.

QUESTIONS/PURPOSES

The purposes of this study were to determine whether preserving the rectus femoris tendon attachment would (1) reduce intraoperative blood loss and length of surgery; (2) improve Harris hip scores (HHS); (3) decrease the rate of complications; and (4) affect the radiographic correction when compared with the classic approach.

METHODS

A retrospective matched cohort study was used to compare the endpoints listed above after PAO using a rectus-preserving approach versus the classic approach. Operative blood loss, preoperative and postoperative hematocrit, duration of surgery, HHS, and postoperative complications were recorded for the two groups. Pelvic radiographs were reviewed for measurement of the lateral center-edge angle, anterior center-edge angle, and Tönnis acetabular inclination angle. A total of 64 patients were included (32 in each group). Followup was at a minimum of 1 year (mean, 20 months; range, 13-44 months).

RESULTS

Blood loss (p = 0.2405), hematocrit change (p = 0.3277), and operative time (p = 0.3960) were similar between groups. At latest followup, the HHS improved in the rectus-preserving (mean improvement, 25; 95% CI, 21-29; p < 0.0001) and control groups (mean improvement, 21; 95% CI, 17-25; p < 0.0001) with no difference in HHS improvement between the groups (mean difference, 4.3; 95% CI, -1.6 to 10.1; p = 0.1523). The complication rate was 12.5% (four of 32) in the rectus-preserving group and 25% (eight of 32) in the classic approach groups, respectively (p = 0.2002). The rectus-preserving approach allowed for similar lateral center-edge angle (p = 0.4463), anterior center-edge angle (p = 0.0936), and Tönnis angle (p = 0.7953) improvement when compared with the classic approach.

CONCLUSIONS

The rectus-preserving approach for PAO is as safe and effective as the classic approach to achieve radiographic correction and HHS improvement at minimum 1 year. Additional investigation is needed to determine whether the rectus-preserving approach allows for improvement in functional recovery including hip flexion strength.

Is cup positioning challenged in hips previously treated with periacetabular osteotomy?

After periacetabular osteotomy (PAO), some patients develop osteoarthritis with need of a total hip arthroplasty (THA). We evaluated the outcome of THA following PAO and explored factors associated with inferior cup position and increased polyethylene wear. Follow-up were performed 4 to 10 years after THA in 34 patients (38 hips) with previous PAO. Computer analysis evaluated cup position and wear rates. No patient had dislocations or revision surgery. Median scores were: Harris hip 96, Oxford hip 38 and WOMAC 78. Mean cup anteversion and abduction angles were 22° (range 7°-43°) and 45° (range 28°-65°). Outliers of cup abduction were associated with persisting dysplasia (CE <25°). THA after PAO can produce excellent clinical results. Persisting acetabular dysplasia following PAO may lead surgeons to place the acetabular component in excessive cup abduction, and this tendency should be recognized at the time of the PAO.

Cyst volume in the acetabulum and femoral head decreases after periacetabular osteotomy

In a series of 26 consecutive patients scheduled for periacetabular osteotomy (PAO), we examined how many had acetabular or femoral head cysts, investigated whether the volume of the cysts changed after PAO, calculated the precision of the method applied and scored their hip symptoms. Magnetic resonance imaging (MRI) was performed before PAO and at 1 and 2½ years post-operatively. The number of cysts was noted and the total cyst volume in each patient was estimated with a design-based stereological method and the precision of the method was calculated.The patients filled out The Hip disability and Osteoarthritis Outcome Score (HOOS) four years after PAO. Preoperatively, 12 patients had acetabular or femoral head cysts (22 cysts), 1 year postoperative, 15 patients had cysts (23 cysts) and 2½ years postoperative, 15 patients had cysts (18 cysts). Mean total acetabular cyst volume per patient decreased significantly from 1 year (1.96 cm³, SD 3.97) to 2½ years (0.96 cm³, SD 1.70) after PAO (p= 0.04). The Limits Of Agreement for measurement of cyst volume was ± 1.73 cm³. The mean subscore for Pain was 75, Symptoms 75, ADL 83, Sport/recreation 63 and Quality Of Life 62. The number of patients having cysts did not change notably after PAO. But the mean total cyst volume/patient decreased significantly between 1 and 2½ years after PAO. The PAO patients rated their hip comparable to the scores for patients six months after total hip replacement.

What factors predict failure 4 to 12 years after periacetabular osteotomy?

BACKGROUND

The goal of periacetabular osteotomy (PAO) is to delay or prevent osteoarthritic development in dysplastic hips. However, it is unclear whether the surgical goals are achieved and if so in which patients. This information is essential to select appropriate patients for a durable PAO that achieves its goals.

QUESTIONS/PURPOSES

We therefore (1) determined hip survival rates; (2) determined how many preserved hips were functionally unsuccessful after PAO; and (3) identified demographic, clinical, and radiographic factors predicting failure after PAO.

METHODS

We retrospectively reviewed 316 patients (401 hips) who had PAO between December 1998 and May 2007. We evaluated radiographic parameters of dysplasia and osteoarthritis and obtained WOMAC scores. Through inquiry to the National Registry of Patients, we identified conversions to THA. Risk factors for conversion to THA were assessed. Minimum followup was 4 years (mean, 8 years; range, 4-12 years).

RESULTS

The overall Kaplan-Meier hip survival rate was 74.8% at 12.4 years. A WOMAC pain score of 10 or more, suggesting clinical failure, was observed in 13% of preserved hips at last followup. Higher age, preoperative Tönnis grade of 2, incongruent hip, postoperative joint space width of 3 mm or less, and postoperative center-edge angle of less than 30° or more than 40° predicted conversion to THA.

CONCLUSIONS

PAO preserved three of four hips with most functioning well at 4- to 12-year followup. When planning surgery, surgeons should attempt to achieve hip congruence and a center-edge angle of between 30° to 40° to improve the durability of PAO.

LEVEL OF EVIDENCE

Level II, prognostic study. See Instructions for Authors for a complete description of levels of evidence.

Periacetabular osteotomy for hip preservation

The Bernese PAO has now been performed for nearly 30 years. In that time, it has proved itself a technically complex procedure with the potential to considerably improve the natural history of the dysplastic hip. Significant refinements in the surgical technique combined with the recognition of FAI, improvements in the understanding of hip biomechanics and acetabular orientation, and more discerning patient selection have improved the outcomes related to this procedure. Although the recovery can be demanding and the potential for complications exists, the results are reproducible and the technique has become the gold standard for acetabular reorientation.