HTO or Unicompartmental Knee Arthroplasty? Choosing Between Two Options for Knee Osteoarthritis (2)

Current comparative data suggest that UKA usually has faster early recovery.

A 2019 analysis included 19 clinical comparative studies and 1359 knees. UKA showed overall advantages in excellent/good rate, Lysholm score, VAS pain, HSS score, time to ambulation, and hospital stay; HTO had an advantage in knee range of motion. No clear difference was found in Tegner activity score.

A 41-patient study with at least 1 year of follow-up showed a similar trend. At 3 and 6 months, function differed between groups and UKA improved faster; by 1 year, Lysholm and Oxford knee scores were not significantly different.

For patients focused on how soon daily walking and life can resume, UKA is often attractive. For younger patients wishing to preserve the joint and maintain greater motion, HTO retains special value.

This is a key difference. HTO changes proximal tibial shape to realign the lower limb, so varus caused by proximal tibial deformity can be corrected directly.

In a comparison of medial unicompartmental osteoarthritis with proximal tibial deformity, both HTO and UKA improved the femorotibial angle, but OWHTO corrected varus more strongly.

If pain and cartilage wear are closely related to obvious bow legs, doctors focus on where the deformity originates. When the main deformity is proximal tibial, osteotomy may better match the treatment goal.

UKA may also improve overall alignment, but its main task is resurfacing the worn joint surface, not large correction of bony deformity.

Usually UKA. Once UKA is completed, the prosthesis immediately carries the joint-surface function, and patients can often start weightbearing earlier if pain, strength, and general condition allow.

After HTO, bone healing is still required, so early weightbearing is more cautious.

Modern locking plates, biplanar osteotomy, and enhanced recovery have changed the older image of prolonged bed rest. In one HTO plus arthroscopy series, partial weightbearing with two crutches was allowed on day 2, continued for 4 to 6 weeks, and full weightbearing was decided after 6-week X-ray review.

HTO recovery speed therefore depends on osteotomy technique, fixation stability, bone healing, and rehabilitation plan.

Both methods can produce good final function if indications are appropriate.

In 60 patients with medial unicompartmental osteoarthritis, 30 underwent UKA and 30 underwent Tomofix-fixed HTO. Postoperative HSS score, pain score, and femorotibial angle showed no clear difference, while HTO had greater knee range of motion.

The 2019 analysis also found UKA advantages in several early clinical indicators, better range of motion after HTO, and no statistically significant difference in revision rate between common medial opening-wedge HTO and UKA.

HTO requires osteotomy, so risks relate mainly to bone healing, correction angle, and internal fixation.

Potential problems include delayed union or nonunion, lateral cortical hinge fracture, undercorrection or overcorrection, implant irritation, infection, neurovascular injury, and venous thrombosis.

Medial opening-wedge HTO preserves bone stock and corrects alignment, but the osteotomy gap must heal. Poor bone quality, smoking, or other healing risks require caution.

If osteoarthritis has clearly involved multiple compartments, shifting the weightbearing axis alone cannot solve all joint-surface wear.

UKA implants an artificial prosthesis, so prosthesis-related issues must be considered.

Risks include infection, thrombosis, loosening, wear, polyethylene bearing dislocation, periprosthetic fracture, and later surgery because osteoarthritis progresses in other compartments.

UKA has indication requirements. Marked ligament instability, severe multi-compartment disease, or inflammatory arthritis requires reassessment.

Artificial joints have lifespan and revision considerations, especially in very young and highly active patients who will use the joint for decades.

Doctors evaluate medial and lateral joint spaces under weightbearing and use full-length standing X-rays to assess the mechanical axis, degree of varus, and whether deformity mainly comes from the femur or tibia.

MRI further assesses medial, lateral, and patellofemoral cartilage, plus meniscus, cruciate ligaments, and other soft tissues.

Range of motion, flexion contracture, collateral stability, age, job, exercise habits, and future activity demands are also reviewed.

Two reports both saying medial compartment osteoarthritis can still lead to different treatment plans.

For eligible younger, active patients with varus, HTO does preserve native joint structures.

It does not replace the medial compartment with an artificial surface and directly addresses abnormal loading. This appeals to patients who want to keep higher physical activity.

However, preserving the native joint does not guarantee avoiding future arthroplasty. Osteoarthritis may progress. HTO aims to improve symptoms, restore alignment, and delay further degeneration when possible.

If cartilage is already bone-on-bone, pain is significant, and age and activity demand fit UKA better, choosing HTO only to preserve the original joint may not give the desired result.

The two procedures can be compared through a practical framework.

Younger, active patients with clear varus, desire for joint preservation, and good lateral-compartment cartilage often have more reason to discuss HTO.

Older patients with severe medial wear, clear pain, desire for faster weightbearing and daily recovery, and suitable UKA indications may fit UKA better.

Patients aged 55 to 65 with both obvious varus and severe medial wear often sit in the overlap zone. Full-length X-rays, cartilage damage, ligament stability, activity demand, and personal expectations should be considered together.

Current evidence shows both procedures can improve unicompartmental knee osteoarthritis, but many comparisons have small samples and heterogeneous selection criteria, HTO techniques, and UKA implants. A 1359-knee analysis also noted heterogeneity and limited randomized trials, so no single indicator should be converted into one universal surgical answer.