Hemi-Arthroplasty — Cost, Top Hospitals & Success Rates | MyMedicPlus

Hemi-arthroplasty (also written hemiarthroplasty) is a partial hip replacement in which the femoral head and neck are excised and replaced with a metal prosthesis that articulates with the patient's native acetabular cartilage. Unlike total hip arthroplasty (THA), which replaces both the femoral and acetabular sides of the joint, hemi-arthroplasty replaces only the femoral component, preserving the native acetabulum and its surrounding ligamentous structures.

The procedure was first described in the 1940s by the Judet brothers and refined by F.R. Thompson and Austin T. Moore, whose designs remain in widespread use today. The fundamental rationale for hemi-arthroplasty in acute hip fracture management is speed and simplicity: in elderly, low-demand patients with displaced femoral neck fractures, replacing the fractured femoral head avoids the high failure rates of internal fixation (avascular necrosis, non-union) while being technically faster and less complex than THA.

Two principal categories of hemi-arthroplasty exist:

• Monoblock (unipolar) designs: A fixed-diameter metallic femoral head directly contacts the acetabular cartilage. The Austin Moore prosthesis (uncemented, fenestrated stem) and Thompson prosthesis (cemented smooth stem) are the canonical examples. The head-neck-stem assembly is a single cast unit.
• Bipolar designs: A modular system in which a small inner femoral head articulates within a larger outer shell, which in turn contacts the acetabulum. Theoretical motion distribution between the inner and outer bearings reduces acetabular erosion compared with monoblock implants, though clinical long-term evidence for this advantage is mixed.

Contemporary evidence positions hemi-arthroplasty as the preferred surgical treatment for displaced (Garden III and IV) intracapsular femoral neck fractures in elderly patients with low-to-moderate functional demand and acetabular cartilage that is radiologically intact. The procedure allows immediate full weight-bearing, minimises non-union and avascular necrosis risk, and facilitates early mobilisation — the most critical determinant of recovery in elderly fragility fracture patients.

Hemi-arthroplasty is used in a defined set of hip pathologies, predominantly acute trauma in the elderly:

Displaced Intracapsular Femoral Neck Fractures (Primary Indication)

Garden classification grades III (incomplete displacement) and IV (complete displacement) represent the core indication. These fractures disrupt the blood supply to the femoral head via the ascending cervical arteries, placing the head at high risk of avascular necrosis (AVN) — occurring in 15 to 30% of cases after internal fixation. Hemi-arthroplasty eliminates AVN and non-union as failure modes by removing the compromised femoral head entirely. The annual global incidence of hip fractures exceeds 1.5 million cases, with displaced intracapsular fractures comprising approximately 40 to 50% of all hip fractures.

Femoral Head Avascular Necrosis (Ficat-Arlet Stages III and IV)

Advanced AVN with femoral head collapse (Ficat-Arlet stage III/IV, ARCO stage III/IV) produces severe hip pain and loss of function when articular congruity is destroyed. In elderly patients with intact acetabular cartilage and low functional demand, hemi-arthroplasty provides reliable pain relief with shorter surgical time than THA. In younger or active patients, THA is generally preferred due to superior long-term outcomes.

Failed Internal Fixation of Femoral Neck Fractures

Cannulated screw fixation or dynamic hip screw (DHS) failure — through AVN, non-union, or implant cutout — may necessitate salvage hemi-arthroplasty. This scenario involves more complex reconstruction due to prior hardware and bone loss, and carries higher complication rates than primary hemi-arthroplasty.

Pathological Fractures of the Femoral Neck

Metastatic deposits in the proximal femur causing impending or actual femoral neck fractures in patients with limited life expectancy (<12 months) may be treated with hemi-arthroplasty when acetabular involvement is absent. Reconstruction nails or proximal femoral replacement prostheses are preferred for more extensive metastatic involvement.

Femoral Head Fractures

Pipkin type III and IV femoral head fractures (associated with acetabular fractures) in elderly patients may be managed with hemi-arthroplasty when head reconstruction is not feasible.

Selecting between hemi-arthroplasty (HA) and total hip arthroplasty (THA) for displaced femoral neck fractures is the central decision in hip fracture surgery, driven by pre-fracture functional status, cognitive state, acetabular integrity, life expectancy, and patient preference.

Factors Favouring Hemi-Arthroplasty

• Age and functional demand: Patients over 75 to 80 years with moderate-to-low pre-fracture mobility (walking with a walking frame, housebound, or community walking with one stick) are well suited to HA. The procedure is faster, has lower intraoperative blood loss, and avoids the acetabular component positioning complexity of THA.
• Cognitive impairment: Patients with dementia or delirium are at higher risk of hip dislocation (increased risk with THA due to more demanding precautions). HA has somewhat lower dislocation rates than THA in cognitively impaired patients, though this difference is modest with modern anterolateral approaches.
• Normal acetabular cartilage: Hemi-arthroplasty is only appropriate when the acetabulum has no significant osteoarthritis. If moderate-to-severe acetabular arthrosis is present (Toennis grade 2 to 3), THA is mandated to avoid persistent groin pain from a metal head articulating with damaged articular cartilage.
• High anaesthetic risk: HA is shorter (45 to 60 minutes versus 80 to 120 minutes for THA), reducing anaesthetic exposure in medically frail patients.

Factors Favouring Total Hip Arthroplasty

• Pre-fracture high activity level (community ambulator without aids, active lifestyle)
• Age below 70 to 75 years with good bone quality
• Pre-existing ipsilateral hip osteoarthritis or inflammatory arthritis
• Normal or near-normal cognitive function facilitating THA dislocation precautions
• Patient expectation for high-level physical activity and long-term function

Cemented vs Uncemented Fixation

UK NICE guidelines and the NICE HipArthroplasty for Hip Fracture guideline (2022) recommend cemented fixation for all hemi-arthroplasties in elderly patients with osteoporotic bone, citing lower periprosthetic fracture rates and superior early stability versus press-fit uncemented stems. The HEALTH and TRIGEN trials have reinforced this recommendation. Cement implantation syndrome (hypotension, cardiac arrhythmia during cement pressurisation) is a rare but serious complication, managed by haemodynamic monitoring during cement insertion.

The operative choices in hemi-arthroplasty span prosthesis design, fixation method, and surgical approach, each with distinct biomechanical and clinical implications.

Austin Moore Prosthesis (Uncemented Monoblock)

Introduced in 1952, the Austin Moore prosthesis has a fenestrated stem that allows bony ingrowth through the stem fenestrations for biological fixation. It is press-fitted into the proximal femoral canal. The Austin Moore is technically simpler and avoids cement-related risks (fat embolism, cement implantation syndrome). However, in osteoporotic bone, press-fit fixation can be inadequate, leading to subsidence, thigh pain, and early mechanical failure. Contemporary evidence and most national guidelines now recommend cemented alternatives over Austin Moore in the elderly.

Thompson Prosthesis (Cemented Monoblock)

The Thompson prosthesis has a smooth, tapered stem fixed with polymethylmethacrylate (PMMA) bone cement. Cemented fixation achieves immediate rotational stability and pain-free early weight-bearing superior to uncemented designs in osteoporotic bone. The monoblock design makes head size selection less flexible than modular systems, but the simplicity and reliability of cemented fixation have maintained its widespread use in high-volume hip fracture programmes.

Bipolar Hemi-Arthroplasty

Bipolar implants (e.g., Stryker Exeter Bipolar, DePuy Pinnacle Bipolar) consist of a femoral stem bearing a modular inner femoral head that articulates within a larger outer bearing shell. The outer shell contacts the acetabulum. The dual-mobility design theoretically distributes load and motion between the inner and outer bearings, potentially reducing acetabular erosion in long-term survivors. In practice, RCT data comparing bipolar to monoblock designs show similar functional outcomes and re-operation rates at 5 years, with bipolar prostheses costing significantly more.

Surgical Approaches

• Posterolateral (Southern) approach: Most widely used; provides excellent femoral stem access but requires posterior capsule repair and has a 3 to 5% dislocation rate without capsular repair, falling to 1 to 2% with meticulous repair
• Anterolateral (Watson-Jones) approach: Preserves the posterior capsule and short external rotators; lower dislocation rate (1 to 2%); slightly more demanding exposure for femoral stem preparation
• Direct anterior approach (DAA): Intermuscular plane; lower early dislocation risk; used by specialist hip arthroplasty surgeons but less universally adopted in hip fracture emergencies

Hemi-arthroplasty provides reliable pain relief and early mobility in elderly patients with displaced hip fractures, with outcomes closely tied to pre-operative functional status and systematic perioperative care.

Immediate Mobilisation

The primary advantage over internal fixation is the ability to bear full weight from postoperative day 1. Immediate weight-bearing is critical in elderly patients — prolonged bed rest carries risk of pressure sores, pneumonia, deep vein thrombosis, deconditioning, and delirium. Hip fracture programmes using systematic orthogeriatric co-management and next-day mobilisation protocols have reduced 30-day mortality to below 5% at high-volume centres.

Elimination of Avascular Necrosis and Non-Union

The defining advantage over internal fixation is that by removing the femoral head, HA eliminates avascular necrosis (15 to 30% after fixation) and non-union (10 to 15% after fixation) as failure modes. Reoperation rates after HA are 4 to 8% versus 20 to 30% after internal fixation for displaced fractures, driving strong guideline consensus in favour of arthroplasty for Garden III and IV fractures in the elderly.

Functional Recovery

At 12 months, 60 to 70% of hemi-arthroplasty patients recover to their pre-fracture ambulatory level. Harris Hip Score (HHS) and Oxford Hip Score (OHS) at 1 year are comparable between HA and THA in low-demand patients. THA demonstrates superiority over HA in active patients (HHS improvement of 5 to 8 points at 24 months) but this difference diminishes in sedentary elderly patients.

Pain Relief

Over 85% of patients report satisfactory pain relief at 6 months post-HA. Anterior groin pain from acetabular erosion (occurring in 5 to 10% of long-term HA survivors with monoblock designs) is the main long-term pain driver and may indicate conversion to THA in sufficiently active patients.

Surgical Efficiency

Hemi-arthroplasty is shorter (45 to 60 minutes), requires less blood transfusion (mean 0.8 units versus 1.2 units for THA), and has lower intraoperative complication rates in non-specialist hands compared to THA, making it well-suited to high-volume hip fracture programmes with trainees or non-specialist arthroplasty surgeons.

Hemi-arthroplasty in elderly hip fracture patients carries meaningful perioperative and long-term risks, amplified by the typically frail population and the urgency of surgery.

Dislocation

Dislocation is the most common early mechanical complication of HA, occurring in 2 to 4% with the posterolateral approach and 1 to 2% with anterolateral approaches. Risk factors include poor tissue quality, obesity, revision surgery, cognitive impairment impairing compliance with precautions, and inadequate posterior capsule repair. Acute dislocations are usually reduced closed under sedation; recurrent dislocations may require revision to constrained liners, Girdlestone excision arthroplasty, or conversion to THA.

Periprosthetic Fracture

Intraoperative calcar or shaft fractures occur in 1 to 3%, particularly with uncemented press-fit stems in osteoporotic bone — a primary reason guideline bodies favour cemented fixation. Postoperative periprosthetic fractures (B-type, Vancouver classification) around well-fixed stems are managed with plate fixation; those around loose stems require revision with long cemented or uncemented revision implants.

Infection

Deep periprosthetic joint infection (PJI) affects 1 to 3% of hip fracture arthroplasty patients — higher than elective THA (0.5 to 1%) due to urgent non-sterile emergency presentations, higher frailty burden, and impaired immune response. Early acute PJI is managed with debridement, antibiotics, and implant retention (DAIR) if the prosthesis is well-fixed and symptoms began within 3 to 4 weeks of implantation. Chronic or late PJI usually requires two-stage revision.

Acetabular Erosion (Long-Term)

Protrusio acetabuli (medial migration of the femoral head through the acetabulum) and cartilage erosion by the metal monoblock head occur in 5 to 15% of long-term survivors, typically appearing 5 to 10 years post-implantation. This complication is more common with monoblock designs and is the main driver of late conversion to THA. Bipolar designs were developed to reduce this risk by distributing motion, but long-term superiority over monoblock has not been conclusively demonstrated in RCTs.

Leg Length Discrepancy

Leg length discrepancy (>1 cm) occurs in 5 to 10%, related to femoral neck resection level and stem siting. Most patients tolerate discrepancies below 1.5 cm without functional impairment. Shoe lifts correct symptomatic discrepancy.

Mortality Considerations

30-day mortality after hip fracture surgery (all types) ranges from 5 to 10%, reflecting the frail, elderly population rather than the surgical procedure itself. 1-year mortality is 20 to 30% in those over 80 years. Systematic orthogeriatric co-management and time-to-surgery within 36 hours (NICE guideline target) substantially reduce mortality.

Recovery after hemi-arthroplasty depends heavily on pre-fracture function, perioperative medical optimisation, and systematic physiotherapy-led rehabilitation.

Immediate Postoperative Period

Full weight-bearing with a walking frame begins on postoperative day 1 under physiotherapy supervision. Pre-operative anaemia correction (target haemoglobin >100 g/L before surgery) and cell salvage during surgery minimise transfusion requirements. Pain is managed with multimodal analgesia (paracetamol, NSAIDs where tolerated, regional nerve blocks — fascia iliaca block, pericapsular nerve group block) to facilitate early mobilisation while minimising opioid-related sedation and delirium risk. Urinary catheterisation is removed as soon as feasible (typically day 1 to 2) to reduce UTI risk.

VTE Prophylaxis

Pharmacological VTE prophylaxis is mandatory for at least 28 to 35 days post-surgery. Low molecular weight heparin (LMWH — enoxaparin, dalteparin) or direct oral anticoagulants (rivaroxaban, apixaban — preferred in patients not at high bleeding risk) are guideline-recommended per NICE CG92 and ACCP guidelines. Mechanical prophylaxis (intermittent pneumatic compression devices) is used from the day of surgery until mobile and while pharmacological agents are temporarily withheld.

Physiotherapy and Mobilisation Goals

• Day 1 to 2: Sit out of bed, transfer training, begin walking with a walking frame
• Day 3 to 5: Stair practice, longer corridor distances, assessment of home environment needs
• Week 2 to 6: Transition from walking frame to crutches or stick where appropriate; community physiotherapy or inpatient rehabilitation facility for patients unable to return home safely
• Week 6 to 12: Outdoor mobility, driving assessment (typically 6 weeks post-surgery), return to social activities

Hip Precautions

Standard posterior hip dislocation precautions — avoiding hip flexion beyond 90 degrees, adduction, and internal rotation — are maintained for 6 weeks post-posterolateral approach surgery. These precautions allow scar tissue to mature around the capsular repair. With anterolateral or anterior approaches, precautions are less restrictive.

Radiographic and Clinical Follow-Up

Outpatient review at 6 weeks includes clinical assessment and plain anteroposterior pelvis and lateral hip radiographs to check stem position, cement mantle integrity, and early periprosthetic fracture. Further follow-up at 12 months assesses functional recovery (Harris Hip Score, Oxford Hip Score) and identifies early acetabular erosion or stem subsidence. Annual review is recommended in long-term survivors to detect progressive acetabular erosion requiring conversion to THA.

Hemi-arthroplasty is performed as an emergency procedure in most countries and is therefore covered by national health systems in high-income countries. Medical tourism for planned hemi-arthroplasty (e.g., for AVN or delayed fracture management) follows elective hip surgery pricing.

Approximate Costs (USD)

• United States: USD 20,000 to 45,000 all-inclusive (hospital charges, surgeon, anaesthesia, implant). The Austin Moore or Thompson prosthesis costs USD 500 to 1,500; cemented bipolar systems USD 2,000 to 5,000. Inpatient rehabilitation adds USD 5,000 to 15,000 for 5 to 10 days.
• United Kingdom (NHS): Fully funded for NHS patients; private sector HA GBP 10,000 to 18,000.
• India: USD 3,000 to 7,000 including implant and 5 to 7 days hospitalisation at accredited centres. Implant costs are significantly lower due to local manufacturing and generic imports.
• Thailand: USD 6,000 to 12,000 including rehabilitation.
• Germany: EUR 12,000 to 22,000.
• Turkey: USD 5,000 to 10,000.

Key Cost Drivers

• Implant design: Monoblock Austin Moore or Thompson prostheses are the least expensive; cemented bipolar systems cost 3 to 5 times more per implant
• Cement versus uncemented: PMMA bone cement, mixing system, and pressurisation equipment add USD 300 to 500 but reduce reoperation costs from mechanical failure
• Length of inpatient stay: Hip fracture rehabilitation is the largest cost driver — inpatient rehabilitation facility stays of 5 to 14 days represent 30 to 50% of total episode cost in the US
• Orthogeriatric co-management: Dedicated hip fracture units with orthogeriatric care have higher upfront costs but reduce 30-day readmissions and 1-year care costs significantly
• Revision surgery: Acetabular erosion requiring conversion to THA adds USD 25,000 to 50,000 (US) to the total treatment cost over the implant lifetime

The decision between hemi-arthroplasty and its alternatives is determined primarily by fracture pattern, patient age and activity level, and acetabular status.

Total Hip Arthroplasty (THA)

THA replaces both the femoral head and the acetabular socket, eliminating acetabular erosion as a long-term failure mode and delivering superior functional outcomes in active patients. The HEALTH trial (2017), the largest RCT comparing THA versus HA for displaced femoral neck fractures, found higher Harris Hip Scores and fewer secondary procedures (6.4% versus 11.1%) with THA at 24 months in active patients. NICE guidance (NG111, 2017) recommends THA for patients with displaced intracapsular hip fractures who were walking independently outdoors before the fracture and are not cognitively impaired. The key trade-off is longer operative time (80 to 120 minutes), greater surgical complexity, and a modestly higher dislocation risk requiring stricter patient compliance with precautions.

Internal Fixation (Cannulated Screws or Dynamic Hip Screw)

Cannulated screw fixation is the preferred treatment for undisplaced or minimally displaced femoral neck fractures (Garden I and II), where the femoral head blood supply is largely intact and AVN risk is below 5 to 10%. For displaced fractures (Garden III to IV) in patients under 60 years with good bone quality, internal fixation is sometimes attempted to preserve the native femoral head, with conversion to THA if AVN or non-union supervenes. Reoperation rates after fixation for displaced fractures in the elderly are 20 to 30%, versus 4 to 8% for arthroplasty — the primary reason guidelines recommend arthroplasty for elderly patients with displaced fractures.

Conservative (Non-Surgical) Management

Non-operative management (analgesia, bed rest, early mobilisation with traction) is reserved for patients unfit for any anaesthetic — extreme frailty, end-stage illness, or active patient refusal. Outcomes are poor: 6-month mortality approaches 50 to 60%, and persistent pain, pressure sores, and institutional care dependency are near-universal. Non-operative management is only appropriate in palliative or comfort-focused care settings after informed discussion with the patient and family.

Resurfacing and Novel Implants

Hip resurfacing (capping the femoral head rather than replacing it) is used in younger patients with femoral head disease but requires intact femoral head bone stock and is contraindicated in acute fractures. Proximal femoral replacement prostheses (megaprostheses) are used for extensive metastatic disease or failed revision arthroplasty where standard stem fixation is not feasible.