Bilateral periacetabular osteotomy: Definition, Uses, and Clinical Overview

Posted on February 27, 2026 | by drhip

Bilateral periacetabular osteotomy Introduction (What it is)

Bilateral periacetabular osteotomy is a hip-preserving surgery performed on both hips.
It reshapes and reorients the hip socket (acetabulum) to improve how it covers the femoral head.
It is most commonly used for symptomatic hip dysplasia in adolescents and adults with relatively preserved cartilage.
It may be done as two staged operations or, in selected cases, during one surgical setting.

Why Bilateral periacetabular osteotomy used (Purpose / benefits)

The main purpose of a periacetabular osteotomy (PAO) is to correct abnormal hip socket alignment—most often acetabular dysplasia, where the socket is shallow or angled in a way that under-covers the femoral head. Under-coverage can increase contact stress on the cartilage and overload the labrum (the fibrocartilage rim around the socket), contributing to pain, mechanical symptoms, and reduced function.

Bilateral PAO applies this concept to both hips when dysplasia affects each side. In some people, both hips are structurally similar but symptoms may be worse on one side. In others, both hips are symptomatic.

At a high level, the potential benefits of Bilateral periacetabular osteotomy include:

Improved joint mechanics: By repositioning the acetabulum, the goal is to distribute load across a broader, more stable surface area of cartilage rather than concentrating force on the rim.
Improved stability: Better coverage can reduce functional instability (a “giving way” sensation) in some patients with dysplasia.
Symptom reduction: Many patients pursue PAO primarily to address pain and functional limitations that have not improved with conservative management.
Hip preservation: PAO is generally considered a joint-preserving option, aiming to improve the mechanics of the native hip rather than replacing the joint.

It’s important to note that outcomes and durability depend on factors such as cartilage health, degree of deformity, and surgical planning; these details vary by clinician and case.

Indications (When orthopedic clinicians use it)

Orthopedic hip-preservation specialists may consider Bilateral periacetabular osteotomy in scenarios such as:

Symptomatic acetabular dysplasia affecting both hips, especially with activity-related groin or lateral hip pain
Imaging findings consistent with insufficient acetabular coverage and hip instability patterns
Relatively preserved joint space/cartilage (advanced arthritis typically shifts consideration toward other options)
Persistent symptoms despite nonoperative care (for example, activity modification, structured rehabilitation, and anti-inflammatory strategies)
Coexisting labral pathology thought to be driven primarily by dysplasia (labral tears are common in dysplastic hips)
Patients for whom hip preservation is a priority and whose anatomy is amenable to socket reorientation on both sides
Bilateral symptoms that significantly affect walking tolerance, sport participation, or work demands

Contraindications / when it’s NOT ideal

Bilateral periacetabular osteotomy is not appropriate for every patient with hip pain or even every patient with hip dysplasia. Situations where it may be less suitable, or where other approaches may be favored, include:

Advanced hip osteoarthritis (substantial cartilage loss), where reorientation may not address pain drivers
Poor femoral head–acetabulum congruency (the ball and socket do not match well even after repositioning), depending on the underlying anatomy
Severe stiffness or limited hip range of motion that would limit function after correction
Complex deformity patterns that require different or additional procedures (for example, prominent femoral deformities needing femoral-sided correction)
Medical conditions that significantly increase surgical risk (risk assessment varies by clinician and case)
Inability to participate in the rehabilitation process or follow-up monitoring, which can influence safety and outcomes
Situations where total hip arthroplasty (hip replacement) is more aligned with the clinical picture (often considered when arthritis is the dominant issue)

Because “bilateral” implies treating both hips, candidacy also includes whether it is safer to do staged operations versus a single setting; this decision is individualized.

How it works (Mechanism / physiology)

Core biomechanical principle

Bilateral periacetabular osteotomy works by reorienting the acetabulum around the femoral head to improve coverage and load distribution. In dysplasia, forces can concentrate at the rim of the socket, increasing stress on cartilage and the labrum. By repositioning the socket, the intended effect is to shift contact forces to a more favorable area and improve stability.

Relevant hip anatomy (in simple terms)

Acetabulum: The “cup” of the pelvis that forms the hip socket.
Femoral head: The “ball” at the top of the thigh bone (femur).
Articular cartilage: Smooth lining covering the joint surfaces; cartilage health strongly influences outcomes.
Labrum: A ring of tissue around the socket that can be overloaded in dysplasia.
Pelvic bone around the socket: PAO involves controlled cuts in the pelvic bone to allow the socket segment to be repositioned.

Onset, duration, and reversibility

PAO is a structural surgical correction, not a medication or temporary device. Its mechanical effect begins once the acetabular fragment is repositioned and stabilized.
The correction is intended to be long-lasting, but long-term durability depends on cartilage status, joint congruency, and multiple patient-specific factors; results vary by clinician and case.
It is not readily reversible in the way a brace or injection might be. Later procedures, if needed, may include additional hip-preservation work or hip replacement depending on how the joint evolves over time.

Bilateral periacetabular osteotomy Procedure overview (How it’s applied)

Below is a general, simplified workflow. Exact techniques differ across surgeons and centers.

Evaluation / exam – History focused on pain location (often groin), mechanical symptoms, stability sensations, and activity limitations – Physical examination of hip motion, impingement signs, gait, and core/hip strength patterns – Imaging to assess dysplasia and cartilage/joint status (commonly X-rays; MRI may be used to evaluate labrum and cartilage)
Preoperative planning – Measurement of hip coverage and version (socket orientation) – Discussion of whether treatment is staged (one hip first, then the other later) or simultaneous; selection depends on symptoms, health factors, and surgeon preference
Preparation – Anesthesia planning, perioperative risk assessment, and baseline function documentation – Planning for mobility support during early recovery (crutches/walker), as weight-bearing is commonly limited initially (varies by clinician and case)
Intervention (the osteotomy and reorientation) – Controlled bone cuts are made around the acetabulum to mobilize it – The acetabular fragment is repositioned to improve coverage and alignment – The fragment is fixed (often with screws) to allow bone healing
Immediate checks – Intraoperative or postoperative imaging checks alignment and hardware position (practice patterns vary) – Monitoring for early complications such as bleeding, nerve symptoms, or wound issues
Follow-up – Scheduled follow-ups for wound checks and imaging to assess bone healing – Progressive rehabilitation, often emphasizing protected weight-bearing early and gradual return of strength and function over time (timelines vary by clinician and case)

Types / variations

Bilateral periacetabular osteotomy can differ in meaningful ways even when the overall goal is the same.

Staged bilateral PAO
One hip is corrected first, followed by the other at a later date.
Often considered to allow recovery and mobility capacity between operations.
The interval between surgeries varies by clinician and case.
Simultaneous (same-setting) bilateral PAO
Both hips are corrected during one surgical setting in carefully selected patients.
Potential advantages and tradeoffs (blood loss, rehabilitation demands, hospital stay considerations) are individualized.
PAO with additional procedures
Femoral osteotomy (femoral-sided correction): Some patients have combined acetabular dysplasia and femoral deformity that may require complementary correction.
Hip arthroscopy or open labral/cartilage procedures: In selected cases, a surgeon may address labral pathology, cartilage injury, or femoroacetabular impingement (FAI)-type morphology. The sequencing and necessity of combined procedures are debated and vary by clinician and case.
Technique variations
Surgical approach, fixation choices (type/number of screws), and intraoperative imaging methods vary by surgeon training and institutional standards.

Pros and cons

Pros:

Preserves the native hip joint by correcting socket alignment rather than replacing the joint
Targets a root mechanical contributor to symptoms in dysplasia (under-coverage/instability mechanics)
May improve functional stability and load distribution across the joint
Can be tailored to each hip’s anatomy, including different correction angles on right vs left
Offers an option for patients with bilateral dysplasia when nonoperative measures are insufficient
Can be combined with other hip-preservation procedures when clinically appropriate (varies by clinician and case)

Cons:

Major surgery with a meaningful recovery and rehabilitation period
Not ideal when arthritis is advanced or cartilage damage is extensive
Early mobility is often limited due to protected weight-bearing and pain control considerations (varies by clinician and case)
Risks include infection, blood loss, blood clots, nerve irritation, nonunion (incomplete bone healing), and hardware irritation; overall risk profile varies
Some patients may still develop progressive joint degeneration over time despite correction (risk depends on cartilage status and other factors)
Bilateral treatment increases planning complexity (staged vs simultaneous) and can extend the overall recovery journey

Aftercare & longevity

Aftercare following Bilateral periacetabular osteotomy is centered on bone healing, restoring hip function, and monitoring alignment and symptoms over time. While individual protocols differ, the themes below are commonly relevant:

Weight-bearing status: Many surgeons use a period of protected or limited weight-bearing to support healing; the degree and duration vary by clinician and case.
Rehabilitation and movement retraining: Restoring hip strength (especially abductors), pelvic control, and gait mechanics often occurs progressively. The pace is typically guided by symptoms, functional milestones, and imaging.
Follow-up imaging: X-rays are commonly used to assess position and healing of the osteotomy site(s).
Return to work and sport: Job demands (sedentary vs heavy labor) and sport type influence timelines. Recovery is often discussed in terms of phases over weeks to months, and sometimes longer for higher-level athletics.
Bilateral considerations: With staged surgery, overall recovery may feel extended because each hip must heal and be rehabilitated. With simultaneous surgery, early rehabilitation demands may be higher because neither side is fully “normal” during early recovery.
Longevity factors: Outcomes can be influenced by baseline cartilage health, severity of dysplasia, presence of femoral deformities, smoking status, body weight, adherence to follow-up, and the development of osteoarthritis over time. No single factor determines durability, and results vary by clinician and case.
Hardware-related issues: Some patients experience irritation from fixation hardware; if removal is considered, the decision is individualized and depends on symptoms and healing.

This information is general and should be interpreted as an overview rather than a personal recovery plan.

Alternatives / comparisons

Bilateral periacetabular osteotomy sits within a spectrum of care for hip dysplasia and related hip pain. Common alternatives include:

Observation / monitoring
Sometimes appropriate when symptoms are mild, function is good, or imaging does not suggest imminent structural risk.
May be combined with periodic reassessment.
Physical therapy and activity modification
Often used to optimize hip and core strength, movement patterns, and load management.
May help symptoms but does not change bony alignment.
Medications
Anti-inflammatory and analgesic strategies can reduce pain and inflammation but do not correct the underlying socket orientation.
Injections
Intra-articular injections may be used diagnostically (to confirm the joint as the pain generator) or for temporary symptom relief.
Response varies, and injections do not correct dysplasia mechanics.
Hip arthroscopy alone
Can address labral tears or impingement-related findings, but in a truly dysplastic hip, treating the labrum without addressing under-coverage may not resolve the primary mechanical issue. Appropriateness varies by clinician and case.
Femoral osteotomy (without PAO)
In some anatomy patterns, femoral correction may be prioritized, or combined correction may be needed.
Choice depends on whether the dominant problem is acetabular, femoral, or both.
Total hip arthroplasty (THA)
Often considered when arthritis is advanced or symptoms are driven by cartilage loss rather than instability mechanics.
THA replaces the joint surfaces rather than preserving and reorienting the native socket.

In practice, clinicians compare these options based on anatomy, cartilage status, symptom pattern, goals, and risk tolerance—factors that vary by clinician and case.

Bilateral periacetabular osteotomy Common questions (FAQ)

Q: What does “bilateral” mean in Bilateral periacetabular osteotomy?
“Bilateral” means both hips are treated. This can be done in one operation or as two separate operations (staged), depending on patient factors and surgeon preference. The decision is individualized.

Q: Is Bilateral periacetabular osteotomy meant to treat hip arthritis?
PAO is primarily used to correct structural under-coverage/instability from dysplasia, usually when cartilage is still relatively preserved. When arthritis is advanced, hip replacement is often discussed as a more fitting option. Which category a patient falls into depends on imaging and clinical findings.

Q: How painful is recovery after this surgery?
Pain experiences vary widely. Pain management typically involves a structured perioperative plan that may include multiple medication types and rehabilitation strategies. Many people describe the first phase as challenging, with gradual improvement over time.

Q: How long do the results last?
PAO is a structural correction intended to be durable because it changes socket orientation. Long-term results depend on factors like cartilage health, joint congruency, degree of correction, and overall hip biomechanics. Durability and the likelihood of needing future surgery vary by clinician and case.

Q: How long is recovery and when can someone return to work or sport?
Recovery is often discussed in phases: early healing over weeks, functional gains over months, and higher-demand sport readiness sometimes taking longer. Return-to-work timing depends heavily on job demands and whether one or both hips were operated on in a short window. Exact timelines vary by clinician and case.

Q: Will I be able to drive after Bilateral periacetabular osteotomy?
Driving depends on which side was operated on, pain control (especially use of sedating medications), strength and reaction time, and the ability to safely get in and out of the car. For staged bilateral cases, the non-operated side may help with basic function during early recovery, but restrictions still commonly apply. Clearance practices vary by clinician and case.

Q: Will I be non-weight-bearing?
Many postoperative pathways include protected or limited weight-bearing for a period to allow bone healing, but protocols differ. The specific restriction and how it changes over time depend on surgical technique, fixation, and healing progress. This detail varies by clinician and case.

Q: Is it safe to do both hips at once?
Simultaneous bilateral PAO is performed in some centers for selected patients, but it increases logistical and rehabilitation demands. Potential benefits (one anesthesia event, one overall timeline) must be weighed against potential downsides (more demanding early mobility, blood loss considerations). Safety assessment varies by clinician and case.

Q: What affects outcomes the most?
Commonly discussed factors include cartilage condition, severity and type of dysplasia, presence of femoral deformities, accuracy of correction, and adherence to rehabilitation and follow-up. Overall health factors and smoking status can also influence healing. No single factor guarantees a specific result.

Q: What does the cost typically look like?
Costs vary widely based on country, hospital setting, surgeon fees, imaging, physical therapy, and insurance coverage. Bilateral care may involve either one combined hospitalization or two separate episodes of care if staged, which can change overall cost. For any individual situation, cost details depend on local billing and coverage rules.