Tom M. van Raaij

Opposite cortical fracture in high tibial osteotomy: lateral closing compared to the medial opening-wedge technique

Background and purpose The aim with high tibial valgus osteotomy (HTO) is to correct the mechanical axis in medial compartmental osteoarthritis of the knee. Loss of operative correction may threaten the long‐term outcome. In both a lateral closing‐wedge procedure and a medial opening‐wedge procedure, the opposite cortex of the tibia is usually not osteotomized, leaving 1 cm of bone intact as fulcrum. A fracture of this cortex may, however, lead to loss of correction; this was examined in the present study. Patients and methods We used a prospective cohort of 92 consecutive patients previously reported by Brouwer et al. (). The goal in that randomized controlled trial, was to achieve a correction of 4 degrees in excess of physiological valgus. In retrospect, we evaluated the 1‐year radiographic effect of opposite cortical fracture. Opposite cortical fracture was identified on the postero‐anterior radiographs in supine position on the first day after surgery. Results 44 patients with a closing‐wedge HTO (staples and cast fixation) and 43 patients with an opening‐wedge HTO (non‐angular‐stable plate fixation) were used for analysis. 36 patients (four‐fifths) in the closing‐wedge group and 15 patients (one‐third) in the opening‐wedge group had an opposite cortical fracture (p < 0.001). At 1 year, the closing‐wedge group with opposite cortical fracture had a valgus position with a mean HKA angle of 3.2 (SD 3.5) degrees of valgus. However, the opening‐wedge group with disruption of the opposite cortex achieved varus malalignment with a mean HKA angle of 0.9 (SD 6.6) degrees of varus. Interpretation Fracture of the opposite cortex is more common for the lateral closing wedge technique. Medial cortex disruption has no major consequences, however, and does not generally lead to malalignment. Lateral cortex fracture in the medial opening‐wedge technique, with the use of a non‐angular stable plate, leads more often to varus malalignment.

Total knee arthroplasty after high tibial osteotomy. A systematic review

BackgroundPrevious osteotomy may compromise subsequent knee replacement, but no guidelines considering knee arthroplasty after prior osteotomy have been developed. We describe a systematic review of non-randomized studies to analyze the effect of high tibial osteotomy on total knee arthroplasty.MethodsA computerized search for relevant studies published up to September 2007 was performed in Medline and Embase using a search strategy that is highly sensitive to find nonrandomized studies. Included were observational studies in which patients had total knee arthroplasty performed after prior high tibial osteotomy. Studies that fulfilled these criteria, were assessed for methodologic quality by two independent reviewers using the critical appraisal of observational studies developed by Deeks and the MINORS instrument. The study characteristics and data on the intervention, follow-up, and outcome measures, were extracted using a pre-tested standardized form. Primary outcomes were: knee range of motion, knee clinical score, and revision surgery. The grade of evidence was determined using the guidelines of the GRADE working group.ResultsOf the 458 articles identified using our search strategy, 17 met the inclusion criteria. Fifteen studies were cohort study with a concurrent control group, one was a historical cohort study and one a case-control study. Nine studies scored 50% or more on both methodological quality assessments. Pooling of the results was not possible due to the heterogeneity of the studies, and our analysis could not raise the overall low quality of evidence. No significant differences between primary total knee arthroplasty and total knee arthroplasty after osteotomy were found for knee range of motion in four out of six studies, knee clinical scores in eight out of nine studies, and revision surgery in eight out of eight studies after a median follow-up of 5 years.ConclusionOur analysis suggests that osteotomy does not compromise subsequent knee replacement. However, the low quality of evidence precludes solid clinical conclusions.

High tibial osteotomy: closed wedge versus combined wedge osteotomy

BackgroundHigh tibial osteotomy is a common procedure to treat symptomatic osteoarthritis of the medial compartment of the knee with varus alignment. This is achieved by overcorrecting the varus alignment to 2-6° of valgus. Various high tibial osteotomy techniques are currently used to this end. Common procedures are medial opening wedge and lateral closing wedge tibial osteotomies. The lateral closing wedge technique is a primary stable correction with a high rate of consolidation, but has the disadvantage of bone loss and change in tibial condylar offset. The medial opening wedge technique does not result in any bone loss but needs to be fixated with a plate and may cause tibial slope and medial collateral ligament tightening. A relatively new technique, the combined valgus high tibial osteotomy, claims to include the advantages of both techniques without bone loss. Aim of this prospective randomized trial is to compare the lateral closing wedge with the combined wedge osteotomy in patients with symptomatic varus osteoarthritis of the knee.Methods/designA group of 110 patients with osteoarthritis of the medial compartment of the knee with 6-12° varus malalignment over 18 years of age are recruited to participate a randomized controlled trial. Patients are randomized to undergo a high tibial osteotomy, with either a lateral closing wedge technique or a combined wedge osteotomy technique. Primary outcome measure is achievement of an overcorrection of 4° valgus after one year of surgery, assessed by measuring the hip-knee-ankle angle. Secondary objectives are radiological scores and anatomical changes after high tibial osteotomy; pain, functional scores and quality of life will also be compared.DiscussionCombined high tibial osteotomy modification avoids metaphyseal tibial bone loss, decreasing transposition of the tibial condyle and shortening of the patellar tendon after osteotomy, even in case of great correction. The clinical results of the combined wedge osteotomy technique are very promising. Hypothesis is that the combined wedge osteotomy technique will achieve more accurate overcorrection of varus malalignment with fewer anatomical changes of the proximal tibia after one year.Trial registrationDutch Trial Registry (Netherlands trial register): NTR3898.

Technical aspects of revision and functional outcome after revision of the Oxford unicompartmental knee arthroplasty

BACKGROUND This study analysed the technical aspects of revision of the Oxford unicompartmental knee arthroplasty (OUKA) and functional results after revision. METHODS In a historic cohort study we analysed all revised OUKAs that were primarily implanted at our clinic over a 10-year period (1998-2009). The primary aim was to investigate surgical difficulties encountered during revision surgery of the OUKA. Outcomes were the knee society score (KSS), WOMAC (Western Ontario and McMaster Universities), SF-36, VAS pain and VAS satisfaction after revision. RESULTS During the study period, 331 OUKAs were inserted. With an average follow-up of six years and five months (range one month to nine years and eight months), there were 44 (13.3%) OUKAs that needed one or more revision surgery procedures. The average time to revision was three years and eight months (range one month to nine years and five months). The main reasons for revision surgery were bearing dislocation, malpositioning or loosening of a component and progression of osteoarthritis. Most revisions, mainly conversion to primary total knee arthroplasty (TKA), gave few surgical problems. Minor bone loss that needed no augmentation was seen most frequently. The functional outcomes after revision surgery were moderate. CONCLUSION A limited amount of surgical difficulty during revision of OUKA was found; in all total revision cases a primary TKA was implanted. However, in most patients there were moderate functional results as well as disappointing pain and satisfaction scores after revision.

Proximal Tibial Valgus Osteotomy: Lateral Closing Wedge

Valgus-producing high tibial osteotomy (HTO) is a well-accepted treatment modality in active patients with varus malalignment and symptomatic medial unicompartmental osteoarthritis (OA) of the knee. One of the key factors for long-term success of the osteotomy is the achievement of an even distribution of the mechanical load on the knee joint by obtaining an ideal alignment of the lower-extremity mechanical axis. Proper surgical techniques are very important, and lateral closing wedge proximal tibial valgus osteotomy (CWO) is highly effective in achieving the desired overcorrection of 3° to 7° of valgus. The major steps of CWO are (1) preoperative planning, in which the frontal plane varus knee deformity is assessed on a standard whole-leg radiograph; (2) a transverse anterolateral incision from the tubercle toward the posterior aspect of the proximal part of the fibular head; (3) exposure and snaring of the common peroneal nerve; (4) resection of the anterior aspect of the proximal part of the fibular head; (5) use of a calibrated slotted wedge resection guide to perform the osteotomy proximal to the tuberosity under fluoroscopic guidance; (6) removal of an osseous wedge and closure of the osteotomy site, with the medial opposite cortex acting as a hinge; and (7) fixation of the osteotomy site with two step staples. Complications (e.g., nonunion, deep infection, and peroneal neuropathy) are rare. At follow-up, CWO has been shown to improve knee function and reduce pain. Male patients with early-onset knee OA have an almost ten times lower probability of failure of a CWO than women with more degenerative disease. The survival rate, with knee replacement as the end point, is approximately 75% at ten years following CWO. CWO postpones primary total knee arthroplasty (TKA) for a median of seven years, and there is low-quality evidence that osteotomy does not compromise subsequent knee replacement.