Preoperative Assessment and Planning
Preoperative assessment for anterior THA focuses on patient history, physical exam, and imaging. Key tests include X‑ray, CT, and MRI to evaluate bone stock and acetabular version. Labs screen for infection, anemia, and coagulation status. A detailed plan ensures optimal approach selection. follow.!
Key Preoperative Tests and Imaging
Before the operating room, a standardized pre‑operative work‑up establishes the foundation for a safe and successful anterior total hip arthroplasty. The core of this evaluation is a comprehensive imaging protocol that maps the bony anatomy, joint orientation, and soft‑tissue constraints. A true anteroposterior pelvis radiograph with the patient supine and both hips in neutral rotation provides the first glance at acetabular coverage, femoral offset, and any osteophyte burden. When the AP view is insufficient—such as in cases of severe deformity, previous hardware, or suspected dysplasia—a low‑dose computed tomography (CT) scan of the pelvis and proximal femur is obtained. The CT dataset is reconstructed in axial, coronal, and sagittal planes and imported into a three‑dimensional planning software that allows virtual implant sizing, cup orientation, and femoral stem selection. In selected patients, a magnetic resonance imaging (MRI) study is added to evaluate the integrity of the abductor mechanism, the sciatic nerve, and the gluteal musculature, especially when a revision scenario or a complex deformity is suspected. All imaging studies are reviewed by the surgeon and the radiologist in a multidisciplinary meeting to confirm implant positioning targets and to identify any contraindicating pathology.
Laboratory evaluation is equally critical. A complete blood count (CBC) screens for anemia that could compromise intra‑operative hemostasis. Coagulation studies—prothrombin time (PT), activated partial thromboplastin time (aPTT), and international normalized ratio (INR)—ensure that the patient is within therapeutic ranges for anticoagulants. C‑reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are measured to rule out occult infection. In patients with a history of chronic kidney disease or liver dysfunction, serum creatinine and liver function tests are obtained to guide peri‑operative fluid management and drug dosing. A pre‑operative cardiology assessment, including an electrocardiogram (ECG) and, if indicated, a stress test, is performed for patients over 65 or those with significant cardiac risk factors. Finally, a thorough medication review is completed to identify agents that may increase bleeding risk or interact with peri‑operative analgesics. All these tests and imaging studies are compiled into a single pre‑operative dossier that is reviewed with the patient, ensuring that the surgical plan is tailored to the individual’s anatomy, functional status, and comorbidities. This meticulous preparation is the cornerstone of a predictable, low‑complication anterior THA pathway.
Patient Selection Criteria
Ideal candidates for anterior THA are active, low‑BMI patients with isolated osteoarthritis, abductor mechanism, and no prior hip surgery. Contraindications include severe dysplasia, infection, or significant femoral deformity that precludes safe exposure.
Indications and Contraindications for Anterior THA
Anterior total hip arthroplasty (THA) is indicated for patients with primary osteoarthritis, avascular necrosis, or mild dysplasia who desire rapid recovery and minimal postoperative pain. Candidates typically have a BMI <30, good abductor strength, and no previous hip surgeries that alter anatomy. The approach offers direct access to the acetabulum and femur, reducing muscle damage and facilitating early mobilization.
Contraindications include severe acetabular retroversion, significant femoral deformity, or a history of infection. Patients with a high risk of dislocation—such as those with neuromuscular disease, severe hip instability, or a history of recurrent dislocations—should be evaluated for alternative approaches. Additionally, extensive soft‑tissue scarring from prior surgeries or trauma can impede safe exposure and increase complication rates.
Preoperative imaging, including AP pelvis radiographs, lateral hip views, and CT scans, is essential to assess bone stock, version, and potential anatomical variations. A multidisciplinary review involving the surgeon, anesthesiologist, and physiotherapist ensures that the chosen approach aligns with the patient’s functional goals and comorbidities.
Multifactorial risk assessment, including frailty scores and cardiopulmonary assessment, care and informs patient counseling.
Surgical Approach and Technique
The anterior approach places the patient supine, a 10‑cm incision medial to the tensor fascia lata, and dissects between sartorius and tensor fascia lata. Key steps: retract sartorius, protect femoral neurovascular bundle, expose acetabulum, cup placement, femoral preparation, and secure fixationfast.
Anterior Approach Key Steps and Instrumentation
Step 1: Positioning. The patient lies supine on a radiolucent table; the operative leg is abducted 15°. A 10‑cm incision is made medial to the tensor fascia lata. Step 2: Soft‑tissue dissection; The interval between sartorius medially and tensor fascia lata laterally is developed with a blunt dissector, protecting the femoral neurovascular bundle. Step 3: Acetabular exposure. The capsule is opened in a T‑shaped fashion; a specialized acetabular reamer set (Zimmer or DePuy) prepares the cup at 45° inclination and 15° anteversion. Step 4: Femoral preparation. The femur is exposed; a femoral broach system (Stryker or Smith & Nephew) sequentially reames the canal, and a trial component assesses offset and leg length. Step 5: Implant placement. The cup is press‑fit or cemented; the femoral stem is seated, and a modular head is attached. Step 6: Closure. The capsule is repaired, fascia closed with interrupted sutures, and skin closed subcuticularly. Instrumentation includes a 10‑cm incision guide, tensor fascia lata retractor, sartorius retractor, curved acetabular reamer, femoral broach set, modular head assembly, and closure kit. All instruments are sterilized and inspected. Fluoroscopy confirms component position and leg length. This systematic approach ensures accurate implant placement and minimizes soft‑tissue trauma, leading to faster recovery and reduced complications in anterior total hip replacement. The surgical team also monitors intraoperative neurophysiological signals to detect nerve irritation early. Post‑operative imaging is reviewed within 24 hours to verify component alignment. Patients receive a standardized pain regimen and early mobilization plan, which together reduce hospital stay and enhance functional outcomes, and early discharge! .
Intraoperative Management
ECG and pulse oximetry guide fluids during THA. The acetabulum is prepared at 45° inclination and 15° anteversion; a cup and femoral stem are implanted, ensuring leg length; A sterile drain placed, incision closed. Early tod now mobilization begins with a therapist!
Blood Conservation and Intraoperative Monitoring
During anterior THA, meticulous hemostasis is paramount to reduce transfusion risk. Surgeons employ a combination of bipolar cautery, topical tranexamic acid (TXA) 1 g IV 30 min pre‑incision, and a tourniquet‑free approach to preserve soft‑tissue integrity. Intra‑operative monitoring includes continuous ECG, pulse oximetry, capnography, and invasive arterial pressure for early detection of hypotension. A central venous line facilitates rapid fluid resuscitation and allows measurement of central venous pressure, guiding fluid balance. Serial hemoglobin checks daily fast via point‑of‑care testing guide transfusion decisions! The use of a cell‑saver system is considered when anticipated blood loss exceeds 500 mL. Post‑implantation, the field is irrigated with 0.5 L saline and fibrin sealant applied to the acetabular bed. The wound is closed in layers, with a closed suction drain left in place to evacuate residual blood. Post‑operative monitoring continues in the recovery area, with hourly hemoglobin checks for the first 24 h and strict observation for signs of bleeding, such as expanding hematoma or drop in blood pressure. Early mobilization is encouraged once hemodynamic stability is confirmed, as it promotes venous return and reduces thromboembolic complications. Protocol adherence is documented in the operative note, ensuring that each step of blood conservation and monitoring is recorded for audit and quality improvement purposes.
Immediate Postoperative Care
Analgesia (acetaminophen, ketorolac, local block) starts within 2 h. Mobilization begins with physiotherapy; elevation andDVT prophylaxis. Monitor for bleeding, neuro deficits, wound integrity. Discharge criteria: pain <4, ambulation >10 m, stable vitals!
Early Pain Control and Mobilization Protocols
Post‑operative pain management follows a multimodal strategy. Within the first hour, a continuous femoral nerve block delivers 0.25% ropivacaine, supplemented by intravenous acetaminophen 1 g q6 h and ketorolac 15 mg q6 h until day 2. Opioids are reserved for breakthrough pain, using a short‑acting agent at the lowest effective dose. Early mobilization is initiated on post‑operative day 0 with assisted standing and weight‑bearing as tolerated, guided by a physical therapist; The patient uses a walker or crutches for the first 48 h, transitioning to a cane when pain permits. Gait training emphasizes a straight‑line pattern, avoiding hip flexion beyond 90°, and maintaining a neutral pelvis. Continuous monitoring of pain scores (VAS) and functional milestones (e.g., 10 m walk, stair negotiation) informs progression. By day 3, the patient should ambulate independently for at least 30 m, with no assistive device, and perform single‑leg stance for 10 s. Pain control is adjusted based on these metrics, tapering local anesthetic infusions and opioid use. Early physiotherapy also includes active hip abduction and flexion exercises, progressing to resistance training by week 2. Adequate hydration, early ambulation, and DVT prophylaxis with low‑molecular‑weight heparin are integral to the protocol. The goal is to achieve pain scores below 3/10, independent ambulation, and a return to baseline activity levels by the 6‑week mark. All interventions are recorded in the chart for audit and improvement!
Rehabilitation Progression
Phase‑wise rehab starts with gentle ROM, progressing to weight‑bearing as tolerated. Week 1 focuses on hip flexion/abduction, week 2 adds resistance, week 3 targets gait training, and week 4 aims for independent ambulation and stair use. Strengthening, balance, and functional tasks advance by week 6.!
Phase‑wise Physical Therapy Milestones
Week 1 (0–7 days): gentle passive ROM, isometric hip abductor activation, and pain control. Weight‑bearing as tolerated with crutches, targeting 20–30 lbs. Monitor wound and neurovascular status.
Week 2 (8–14 days): active‑assisted ROM, hip flexion to 90°, stationary cycling low resistance. Progress to full weight if tolerated. Begin single‑leg stance on a stable surface.
Week 3 (15–21 days): gait training with walker, heel‑to‑toe contact, and arm swing. Add closed‑chain strengthening: mini‑squats, glute bridges, hip abduction. Stair training without rail, single‑leg hops.
Week 4 (22–28 days): transition to cane or no assist, increase resistance, target 60–70 % pre‑injury strength. Functional tasks: stand from chair without arm support, stair descent only.
Weeks 5–6 (29–42 days): endurance walking 1–2 km, stair climbing without rail, dynamic balance drills. Continue progressive resistance, 60–70 % pre‑injury strength. Monitor instability signs.
Weeks 7–12 (43–84 days): return to daily activities, low‑impact sports, and endurance conditioning. Evaluate gait symmetry, hip stability, and functional performance with standardized tests. Adjust program per goals.
Beyond 6 months: maintain strength, flexibility, and proprioception with a structured exercise plan. Periodic reassessment ensures long‑term joint health and functional independence. Continue to monitor for complications, adjust exercises, and maintain proper form.!
Discharge Planning and Long‑Term Follow‑Up
Discharge criteria: pain <2/10, ambulation without assist, vitals Home exercise: gentle ROM, strengthening, gait training Follow‑up: 2 weeks, 6 weeks, 3 months, 6 months, 1 year Monitor implant, function and care Provide education on precautions.
Criteria, Home Exercise, and Outcome Tracking
Discharge criteria include pain <2/10, independent ambulation, stable vitals, and no wound complications. Home exercise focuses on gradual ROM, strengthening, and gait mechanics. Daily routine: gentle hip flexion/extension, abduction/adduction, and quadriceps sets. Progression: 2–3 times daily, 10–15 reps each, increasing resistance as tolerated. Outcome tracking utilizes patient‑reported outcome measures such as the Harris Hip Score, WOMAC, and SF‑12 at 6‑month and 1‑year intervals. Digital tools like mobile apps or wearable sensors provide real‑time data on activity levels and adherence, enabling clinicians to adjust rehabilitation protocols promptly. Regular telehealth check‑ins complement in‑person visits, ensuring sustained functional gains and early detection of complications. Additional criteria for safe discharge: patient can perform a 10‑step walk without assistance, sit‑to‑stand in 10 seconds, and maintain a single‑leg stance for 5 seconds. Home exercise progression schedule: week 1–2: passive ROM, week 3–4: active‑assisted ROM, week 5–6: active ROM with resistance bands, week 7–8: functional gait training with stair negotiation. Outcome tracking also includes radiographic assessment at 3 months to confirm component positioning and rule out loosening. Patients record pain, swelling, and functional milestones in a diary, which is reviewed at each follow‑up. This structured approach ensures objective measurement of recovery and facilitates timely interventions if progress stalls. The protocol emphasizes patient education on safe transfers, use of assistive devices, and fall prevention strategies. Weight‑bearing status is monitored through gait analysis, and progression to full weight bearing is guided by pain tolerance and radiographic stability. Clinicians also assess muscle strength using manual muscle testing, aiming for at least 4/5 in hip abductors and flexors before allowing independent ambulation. The use of a standardized outcome registry allows comparison across centers and contributes to evidence‑based improvements in care.