Patient-Specific Instrumentation and Return to Activities After Unicondylar Knee Arthroplasty

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Key points

  • Unicompartmental knee arthroplasty (UKA) is an excellent surgical option for isolated medial or lateral unicompartmental osteoarthritis (OA). Initial studies were discouraging, but recent studies report greater than 85% survivorship at 10 years, with approximately 90% of patients reporting good to excellent subjective and objective outcomes.

  • When comparing function and return to recreational activity, UKA is at least equivalent to high tibial osteotomy (HTO).

  • Advantages of UKA versus total knee

Unicompartmental knee arthroplasty

This information is designed to help physicians and health care providers understand

  • Indications and contraindications for UKA

  • Expected outcomes for patients undergoing primary UKA and conversion to TKA

  • Potential complications of UKA

  • Discuss patient specific instrumentation and its impact on technique and preoperative planning

Indications

UKA is typically considered in younger and more active patients but also is considered in older sedentary patients with noninflammatory OA confined to a single tibiofemoral compartment (Fig. 1). To consider UKA, there should be minimal clinical patellofemoral or contralateral compartment symptoms. Knee range of motion (ROM) should include at least 100° of flexion and any fixed flexion contracture should be less than 10°. Historically, additional selection criteria included a maximum of 10° of

Surgical technique

The surgical goals of UKA are to replace damaged articular surfaces, restore limb alignment, and create a mechanical axis close to neutral to avoid overloading the contralateral compartment. Several different UKA guide systems can be used (intramedullary, extramedullary, spacer block, custom cutting blocks, and so forth) to ensure accurate osseous cuts and proper implant position. After surgical reconstruction, the joint line should be parallel to the floor and perpendicular to the mechanical

Outcomes

Outcomes from studies are summarized in Tables 2 and 3.10, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 These tables summarize articles with greater than 10-year follow-up (Table 3) as well as recent articles from post-2010 (see Table 3).2, 3, 4, 5, 6 The authors think that the recent articles highlight the newer implants available as well as many of the long-term studies that have recently been published. Because most current studies have shown survival rates of 85% to 90% at 10 to 15 years of

Complications

A complete list of potential complications is described in Box 1. As with TKR, UKA does also has the possibility of polyethylene wear and is more common with incongruity between the femoral component and the tibial insert. As longer follow-up studies have been performed, a distinction has been made between early and late failures (those occurring after 10 years), with late failures typically due to polyethylene wear. This was addressed by the development of the Oxford unicompartmental knee

Future areas of research

Future research on UKA will likely continue to expand on the indications of this procedure. Return to sports activity in increasingly active 50- to 60-year-old patients will likely necessitate further evaluation. Development of improved implant materials may be required as patients have increasing demands and a strong desire to return to preoperative function. Although the current generation of implants has shown good outcomes for 15 to 20 years with minimal wear, perhaps the next generation of

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References (32)

  • I. Ivarsson et al.

    High tibial osteotomy for medial osteoarthritis of the knee. A 5 to 7 and 11 year follow-up

    J Bone Joint Surg Br

    (1990)
  • A.E. Weale et al.

    Unicompartmental arthroplasty and high tibial osteotomy for osteoarthrosis of the knee. A comparative study with a 12- to 17-year follow-up period

    Clin Orthop Relat Res

    (1994)
  • F.D. Naal et al.

    Return to sports and recreational activity after unicompartmental knee arthroplasty

    Am J Sports Med

    (2007)
  • M.F. Pietschmann et al.

    Sports activities after medial unicompartmental knee arthroplasty Oxford III-what can we expect?

    Int Orthop

    (2013)
  • H.U. Cameron et al.

    A comparison of unicompartmental knee replacement with total knee replacement

    Orthop Rev

    (1988)
  • A.J. Price et al.

    Long-term clinical results of the medial Oxford unicompartmental knee arthroplasty

    Clin Orthop Relat Res

    (2005)
  • Cited by (8)

    • Sports activity and patient-related outcomes after fixed-bearing lateral unicompartmental knee arthroplasty

      2021, Knee
      Citation Excerpt :

      When conservative or joint-preserving methods fail, unicompartmental knee arthroplasty (UKA) has shown to be effective with good outcomes [5–10]. In particular, UKA has gained popularity especially among young and active patients [11–13]. These patients undergoing UKA often have high expectations concerning their postoperative level of activity [11,14–16].

    • Improved Survival of Computer-Assisted Unicompartmental Knee Arthroplasty: 252 Cases With a Minimum Follow-Up of 5 Years

      2017, Journal of Arthroplasty
      Citation Excerpt :

      Despite these drawbacks, we still feel that the results of our study still show that good 5-year survival rates can be achieved by using CAS in UKA surgery. If improvement in survival of UKA can be further demonstrated in large multicenter studies, then using CAS, or any other technique (eg, patient-specific instrumentation, robot-assisted surgery) that consistently improves component alignment [34-37], could improve outcomes and cause revision rates to fall. This shift in balance alongside proven reduced early mortality and morbidity would challenge the contention of not performing UKA for eligible patients because of high failure rates [4].

    View all citing articles on Scopus
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