Precision of Pacient-specific Instrumented Open Wedge High Tibial Osteotomy vs Conventional Technicque

University of Malaga50 enrolled

Overview

This study is a randomized clinical trial that will compare two surgical techniques for patients with knee osteoarthritis and varus deformity who are candidates for medial opening wedge high tibial osteotomy. The goal is to evaluate whether using patient-specific 3D-printed surgical guides improves the accuracy of the bone cut compared with the conventional technique performed with anatomical landmarks and fluoroscopy. A total of 50 adult patients will be randomly assigned to one of two groups: conventional osteotomy or osteotomy assisted by patient-specific instrumentation (PSI). The main outcome is the accuracy of the osteotomy cut, measured by comparing preoperative planning with the postoperative CT scan. Secondary outcomes include leg alignment, surgical time, radiation exposure, complications, and functional recovery assessed with validated questionnaires (KOOS, WOMAC, IKDC, EQ-5D) and gait analysis using depth cameras. Patients will be followed for up to 12 months after surgery to evaluate clinical and radiological outcomes.

Medial opening wedge high tibial osteotomy is a well-established surgical procedure to correct knee alignment in patients with medial knee osteoarthritis and varus deformity. The accuracy of the bone cut is critical for surgical success. However, conventional techniques performed with anatomical landmarks and fluoroscopy may result in variability and suboptimal correction. Recent advances in 3D imaging and printing allow the creation of patient-specific surgical guides designed from preoperative CT scans. These guides may improve the accuracy and reproducibility of the osteotomy. This single-center randomized clinical trial will include 50 adult patients, randomly assigned to undergo conventional osteotomy or osteotomy assisted by patient-specific instrumentation. The main outcome is the accuracy of the osteotomy cut compared with preoperative planning. Secondary outcomes include leg alignment, surgical efficiency, radiation exposure, complications, and functional recovery. Patients will be followed for 12 months.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Eligibility

Sex: ALLMin age: 18 YearsMax age: 70 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Informed consent: able to sign informed consent * Clinical: predominantly medial pain/limitation refractory ≥3-6 months * Mobility: flexion ≥90º and flexion contracture ≤10º Stability: varus/valgus and pivot-shift ≤ grade 1. * Radiology: * Medial gonarthrosis Ahlbäck I-III with preserved lateral compartment. * Patellofemoral Iwano 0-2 without disabling patellofemoral pain. * Varus alignment: HKA 4-10°. * Predominantly tibial deformity (decreased MPTA; LDFA close to normal) according to planning. * Anatomy/technical feasibility: proximal tibial morphology suitable for medial opening osteotomy and PSI guide placement. Exclusion criteria: * Comorbidity/clinical situations: * Inflammatory arthritis (e.g., RA, spondyloarthropathies), unresolved previous joint infection or osteomyelitis. * Severe peripheral vasculopathy (ABI \<0.7), advanced peripheral neuropathy or Charcot foot. * Poorly controlled diabetes (HbA1c \>8.5%), advanced renal/hepatic failure (eGFR \<30 ml/min/1.73 m²; Child-Pugh B/C). * Smoking \>20 cigarettes/day without commitment to cessation; active IV drug use or uncontrolled alcoholism. * BMI \>35 kg/m². * Disorder affecting gait (e.g., neurological disease). * Inability to walk at a speed of at least 0.8m/s * Anatomy/radiology * Multiplanar deformities not correctable with isolated medial opening tibial valgus osteotomy (e.g., dominant femoral deformity). * Severe medial subchondral bone defect or extensive necrosis. * Sequelae of proximal tibia fracture or previous ipsilateral HTO that prevent correction or guide use. * Treatments/medication and logistics * Anticoagulation/antiplatelet therapy that cannot be suspended or bridged. * Systemic corticosteroids \>10 mg/day or high-risk immunosuppressants without possibility of adjustment. * Intra-articular infiltration (HA/CS/PRP) within the previous 60 days (respect defined wash-out). * Pregnancy. * Participation in another interfering trial. * Inability to undergo CT (e.g., uncontrollable claustrophobia). * Inability to complete ≥12 months of follow-up.

Outcomes

Primary Outcomes

Angular precision in AP and lateral planes

Difference between planned and executed angles in AP and lateral planes

Time frame: Immediate postoperative period

Distance to joint line

Difference between planned and executed distance between osteotomy cut and and joint line

Time frame: Immediate postoperative period

Secondary Outcomes

Postoperative alignment (HKA angle)

Difference between planned and achieved hip-knee-ankle angle

Time frame: Immediate postoperative period

Posterior tibial slope (PTS)

Difference between planned and achieved tibial slope

Time frame: Immediate postoperative period

Surgical time

Duration from skin incision to closure

Time frame: Day of surgery

Number of fluoroscopic images

Total intraoperative fluoroscopy shots

Time frame: Day of surgery

Radiation dose

Cumulative radiation exposure during surgery (mGy)

Time frame: Day of surgery

Intraoperative complications

Events such as hinge fracture or neurovascular injury

Time frame: Day of surgery

Postoperative complications

Infection, delayed bone healing, thrombotic events

Time frame: From surgery to end of 12 month follow-up

Reoperation

Need for additional surgical intervention

Time frame: From surgery to end of 12 month follow-up

Functional recovery

Time to full weight-bearing without assistance

Time frame: From surgery to end of 12 month follow-up

Radiographic consolidation

Time to radiographic evidence of bone healing

Time frame: From surgery until the end of the 12 month follow-up

30 Sit to Stand Test

Amount of sit-to-stands that can be achieved by the patient in a 30 second window

Time frame: From surgery until the end of the 12 month follow-up

Visual Analog Scale (VAS for pain)

Range 0-10, where 0 = no pain and 10 = worst imaginable pain. Higher scores indicate worse outcome.

Time frame: From surgery until the end of the 12 month follow-up

Percentage of patients with a +-2º correction within the planned osteotomy

Precision of the alignment of the knee with respect tot he planned osteotomy

Time frame: Immediate postoperative period

Timed-Up-and-Go

Time that it takes the patient to stand up from a chair and walk 10 meters, turn 180º and return to the starting position

Time frame: From surgery until the end of the 12 month follow-up

Balance Test (from the Short Physical Performance Battery, SPPB)

The balance component of the Short Physical Performance Battery (SPPB) assesses the ability to maintain three standing positions: feet together, semi-tandem, and tandem stand, each for up to 10 seconds. The test is scored from 0 to 4, where 0 = unable to hold any position, and 4 = able to hold the tandem position for 10 seconds. Higher scores indicate better balance performance.

Time frame: From surgery to end of 12 month follow-up

Knee injury and Osteoarthritis Outcome Score (KOOS)

Each subscale scored from 0-100, where 0 = extreme problems and 100 = no problems. Higher scores indicate better outcome.

Time frame: From surgery to end of 12 month follow-up

International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form

Score range 0-100, where 0 = worst knee function and 100 = no limitations. Higher scores indicate better outcome.

Time frame: From surgery to end of 12 month follow-up

Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)

Scored 0-96, where higher scores indicate worse pain, stiffness, and physical function.

Time frame: From surgery to end of 12 month follow-up

EuroQol 5 Dimensions Questionnaire (EQ-5D-5L)

Index score range usually from -0.59 (worst health state) to 1 (perfect health); higher scores indicate better quality of life.

Time frame: From surgery to end of 12 month follow-up

Lower Limb Functional Index (LLFI)

Patient-reported questionnaire that measures lower limb functional status. It consists of 25 items scored as "yes" (1 point), "sometimes" (0.5 points), or "no" (0 points). The raw score is summed and converted to a percentage (0-100). Higher scores indicate greater disability, while lower scores indicate better functional status. Ranges from 0-100. Higher scores mean a worse outcome.

Time frame: From surgery to end of 12 month follow-up

Foot Health Status Questionnaire (FHSQ)

Patient-reported questionnaire assessing foot health across several domains: pain, function, footwear, and general foot health. Each domain score is transformed to a 0-100 scale. Higher scores indicate better foot health and function. Range: 0-100 for each domain. Higher scores mean a better outcome.

Time frame: From surgery to end of 12 month follow-up

Foot Function Index (FFI)

Patient-reported measure assessing foot pain, disability, and activity limitation. Contains 23 items scored on a visual analog scale (0-10). The total score is normalized to a 0-100 scale. Higher scores indicate greater pain, disability, and activity limitation. Range: 0-100. Higher scores mean a worse outcome.

Time frame: From surgery to end of 12 month follow-up

Precision of Pacient-specific Instrumented Open Wedge High Tibial Osteotomy vs Conventional Technicque

Overview

Conditions

Interventions

Eligibility

Locations (1)

Outcomes

Primary Outcomes

Secondary Outcomes

Central Contacts