Opening Wedge Proximal Tibial Osteotomy Research Articles

Biplanar Anterior Opening Wedge Proximal Tibial Osteotomy to Correct Reverse Tibial Slope

Background: Anatomically, native posterior tibial slope (PTS) ranges from 6° to 10° and have significant effects on cruciate ligament stability. PTS <6° is correlated with increased posterior tibial translation (PTT) and force on the posterior cruciate ligament (PCL), predisposing individuals to PCL injuries and an increased risk of PCL graft attenuation. In rare cases, a reverse tibial slope can occur (<0°) as a result of trauma, physeal arrest, or abnormal development. This results in increased PTT and can lead to posterior tibial subluxation. Reverse tibial slopes in patients can be treated with an anterior opening wedge proximal tibial osteotomy, which increases the PTS to a more anatomic position. Indications: Biplanar anterior opening wedge proximal tibial osteotomies are indicated in patients with a reverse tibial slope both with the absence of PCL insufficiency or in conjunction with PCL reconstruction. Technique Description: Under fluoroscopic imaging, 2 guide pins were placed perpendicular to the tibial shaft. An oscillating saw and osteotomes completed the osteotomy in line with the guide pins with the posterior cortex remaining intact. The osteotomy site was slowly opened with a spreader device to 9 mm until the posterior drawer was such that the palpable step-off between the anterior aspect of the medial femoral condyle and the medial tibial plateau was comparable to the contralateral knee. Due to the patient having slight valgus coronal plane alignment, an opening-wedge posteriorly sloped plate was then placed anterolaterally and fixed while wedges held the osteotomy open. Results: Biplanar anterior opening wedge osteotomies correct a flattened PTS and reverse tibial slope, and coronal malalignment, and has been shown to decrease PCL laxity, preventing future PCL failure. Discussion: Biomechanical studies have shown that decreased tibial slope is correlated with an increased risk of PCL injury and PCL graft failure. In patients with reverse tibial slope, experienced instability can mimic PCL insufficiency despite there being no ligamentous damage. We describe a technique that corrects reverse tibial slope and with a discussion of surgical pearls and pitfalls. This technique restores anatomic position and normal function of the knee while correcting the sagittal malalignment that could lead to future injuries. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Revision Transtibial Medial Meniscal Root Repair With Concomitant Medial Opening-Wedge Proximal Tibial Osteotomy

Background: Complete meniscal root tears disrupt dispersion of axial loading forces through hoop stresses. This increases point-loading on tibiofemoral cartilage and leads to chondromalacia and accelerated osteoarthritis (OA). Posterior root tears may be treated successfully with a transtibial pullout repair. Varus malalignment also leads to increased medial compartment pressures, increasing the risk of early OA and putting increased stress on the meniscus and stabilizing knee ligaments. In particular, revision medial meniscal root repairs without correction of varus malalignment are at increased risk of failure. Genu varum may be corrected with a medial opening-wedge proximal tibial osteotomy (OW PTO). Indications: Meniscal root repairs are indicated for acute or chronic tears in active patients with healthy cartilage. OW PTO is indicated for varus malalignment in ambulatory patients with healthy cartilage, or who are at risk for failure of meniscal or ligamentous procedures. Technique Description: After exposure of the osteotomy site, arthroscopy is performed through the incision and the revision posterior meniscus root repair is performed via a double-tunnel transtibial pullout technique. The positioning of these tunnels is modified superiorly so as to not cross the planned osteotomy site. The osteotomy is then performed by drilling 2 guide pins under fluoroscopy to delineate the plane of the cut. An OW plate is placed, and the root repair is tensioned last. Results: Double-tunnel transtibial pullout repairs increase meniscal fixation contact surface and have been shown to be biomechanically superior to all-inside fixation techniques. Medial OW PTO restores knee alignment and reduces supra-anatomic stresses in the medial compartment, additionally decreasing the risk of a revision medial meniscus repair failure. Discussion: Biomechanical studies have shown that meniscal root tears are functionally equivalent to complete meniscectomy. Varus malalignment increases the risk of medial meniscal tears, and reduces the risk of a successful long-term repair. We describe a technique for a revision transosseous posterior root repair with concomitant proximal tibial osteotomy, with discussion of surgical pearls and pitfalls. This technique restores anatomic position and native function of the medial meniscus while correcting tibiofemoral malalignment that could jeopardize the repair. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form.

Reliability of Preoperative Planning Method That Considers Latent Medial Joint Laxity in Medial Open-Wedge Proximal Tibial Osteotomy.

Background:Soft tissue laxity around the knee joint has been recognized as a crucial factor affecting correction error during medial open-wedge proximal tibial osteotomy (MOWPTO). Medial laxity in particular, which represents the changes in joint-line convergence angle (JLCA), affects soft tissue correction.Purpose:The purpose of this study was to quantify medial laxity and develop a preoperative planning method that considers medial laxity.Study Design:Cohort study; Level of evidence, 3.Methods:This study retrospectively reviewed 139 knees in 117 patients who underwent navigation-assisted MOWPTO from January 2014 to July 2019 for symptomatic medial compartment osteoarthritis with varus alignment >5°. We compared the results of 2 preoperative planning methods: conventional Miniaci (n = 47) and latent medial laxity reduction (LMLR) (n = 92). We evaluated the incidence of undercorrection, acceptable correction, and overcorrection. The radiologic parameters were analyzed using multiple linear regression with a stepwise selection model to establish an equation for the optimal preoperative planning method. The intraclass correlation coefficients (ICCs) of intraobserver, interobserver, and intermethod reliability were calculated.Results:The Miniaci method showed a higher incidence of overcorrection (55.3%) than the LMLR method (22.8%) at postoperative 6 months (P = .0006). Multiple linear regression with a stepwise selection model revealed a high correlation coefficient (R 2 = 0.888) for the following equation: Adjusted planned correction angle = 0.596 + 0.891 × Target correction angle – 0.255 × ΔJLCA valgus . Upon simplification, the following equation showed the highest intermethod ICC value (0.991): Target correction angle – ⅓ΔJLCA valgus , while the Miniaci method showed a relatively low ICC value of 0.875.Conclusion:There was a risk of overcorrection after MOWPTO using the conventional Miniaci method. An equation that considers medial laxity may help during preoperative planning for optimal correction during MOWPTO.

Medial Opening Wedge Proximal Tibial Osteotomy: Lessons Learned from a Series of 175 Consecutive Cases.

High tibial osteotomy (HTO) is a surgical procedure aimed at inhibiting the progression of osteoarthritis of the knee joint. The aim of this study was to identify factors influencing the functional outcome after opening wedge valgus HTO. A total of 175 cases (155 patients) of varus-correcting high tibial open-wedge osteotomies using the Tomofix plate were reviewed retrospectively. Patients answered the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire and 4 survey follow-up questions. A total of 76 of the 155 patients studied (84 of the 175 knees) completed the KOOS questionnaire, on average 3.1 years (SD 1.8 years) after the surgery. The median scores (with median absolute deviations [MAD]) for the KOOS pain, symptoms, daily activities, sports, and quality of life sections were, respectively, 76.4 (MAD 12.5), 75.0 (MAD 14.3), 85.3 (MAD 11.8), 50.0 (MAD 25.0), and 59.4 (MAD 21.9). No cases of nonunion were observed throughout the length of the study. Identified predictors of worse outcomes were higher weight and body mass index, limited knee flexion, genu varum and tibial varus of small magnitude, active smoking status at the time of surgery, further surgery for plate removal, and some grades of chondropathy in the patellofemoral, medial tibial, and femoral compartments. Patient gender, joint obliquity and over- or undercorrection were not associated with any of the outcomes. This study shows good results following valgus HTO that are comparable to outcomes following total knee arthroplasty, reinforcing the option of HTO as a valid alternative for total knee arthroplasty.

Tibial Slope Can Be Maintained During Medial Opening-Wedge Proximal Tibial Osteotomy With Sagittally Oriented Hinge, Posterior Plate Position, and Knee Hyperextension: A Cadaveric Study

The purpose of this study is (1) to determine if, when optimizing modern techniques, medial opening-wedge osteotomies can effectively maintain tibial slope and (2) to determine how different magnitude coronal plane corrections affect tibial slope. Proximal tibial osteotomies (PTOs) were performed on 10 fresh-frozen cadaveric knees leaving a consistent lateral hinge, using either a 5-mm or a 10-mm trapezoidal wedged osteotomy plate. Techniques including posterior plate placement; a trapezoidal, sloped plate; and knee hyperextension were used during plate fixation to help close the anterior osteotomy gap. Medial coronal proximal tibia angle and posterior tibial slope were measured preosteotomy, after a 5-mm implant, and after a 10-mm implant using true anteroposterior and lateral fluoroscopic images. Three independent observers performed all radiographic measurements, and intraclass correlation coefficients were calculated. The 5-mm and 10-mm osteotomy plates increased the coronal medial proximal tibia angle by a mean of 3.4° (range, 3.0°-3.7°) and 7.3° (range, 6.7°-7.7°), respectively. The 5-mm and 10-mm trapezoidal wedged osteotomy plates decreased the posterior tibial slope by a mean of 0.9° (range, 0.5°-1.2°) and 0.3° (range, 0°-0.6°), respectively. Intraobserver reliability was found to be high for both the coronal medial proximal tibia angle (intraclass correlation coefficient [ICC]= 0.897 [0.821-0.946]) and the tibial slope measurements (ICC= 0.761 [0.672-0.826]). When optimizing the medial opening-wedge proximal tibial osteotomy, including utilization of a sagittally oriented hinge, placement of a trapezoidal plate posteriorly, and fixation with knee hyperextension, posterior tibial slope can be maintained regardless of the degree of coronal correction. Tibial slope has a significant effect on cruciate ligament stress and a better understanding of coronal plane correction, and its effect on tibial slope is critical when performing proximal tibia osteotomies.

Treatment for Symptomatic Genu Recurvatum: A Systematic Review.

Background:Symptomatic genu recurvatum is a challenging condition to treat. Both osseous and soft tissue treatment options have been reported to address symptomatic genu recurvatum.Purpose/Hypothesis:The purpose of this article was to review the current literature on surgical treatment options for symptomatic genu recurvatum and to describe the associated clinical outcomes. We hypothesized that anterior opening-wedge proximal tibial osteotomy (PTO) would be the most common surgical technique described in the literature and that this intervention would allow for successful long-term management of symptomatic genu recurvatum.Study Design:Systematic review; Level of evidence, 4.Methods:A systematic review was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, with the inclusion criterion of surgical treatment options for symptomatic genu recurvatum. Recurvatum secondary to polio, cerebrovascular accident, or cerebral palsy was excluded from this review.Results:A total of 311 studies were identified, of which 6 studies with a total of 80 patients met the inclusion criteria. Causes of genu recurvatum included physeal arrest; soft tissue laxity; and complications related to fractures, such as prolonged immobilization and malalignment. Mean follow-up times ranged from 1 to 14.5 years postoperatively. There were 5 studies that described anterior opening-wedge PTO, 2 of which used the Ilizarov distraction technique. All 3 studies that used PTO without the Ilizarov technique reported correction of recurvatum and increased posterior tibial slope; 2 of these studies also included subjective outcomes scores, reporting good or excellent outcomes in 70% (21/30) of patients. Of the studies that used the Ilizarov technique, both reported correction of recurvatum and increased posterior slope from preoperative to postoperative assessments. Both of these studies reported good or excellent subjective outcomes postoperatively in 89.5% (17/19) of patients. Additionally, 1 study successfully corrected recurvatum by performing a retensioning of the posterior capsule to address knee hyperextension, although follow-up was limited to 1 year postoperatively.Conclusion:Anterior opening-wedge PTO, with or without postoperative external fixation with progressive distraction, was found to be a reliable surgical treatment for symptomatic genu recurvatum. After surgical management with PTO, patients can expect to achieve correction of knee hyperextension, restoration of a more posterior tibial slope, and increased subjective outcome scores.

Return to Work and Sport After Proximal Tibial Osteotomy and the Effects of Opening Versus Closing Wedge Techniques on Adverse Outcomes: A Systematic Review and Meta-analysis

Background: Although many studies have reported successful functional outcomes after proximal tibial osteotomy (PTO), a paucity of literature has sought to quantify outcomes and current rates of return to sport (RTS) and return to work (RTW) after PTO. Purpose: To (1) determine current rates of RTS and RTW after PTO and (2) quantify the incidence of complications and conversion to total knee arthroplasty (TKA) after PTO for all patients as well as those undergoing opening and closing wedge PTO. Study Design: Systematic review and meta-analysis; Level of evidence, 4. Methods: The Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed (2008-2019), EMBASE (2008-2019), and MEDLINE (2008-2019) databases were queried. Data pertaining to article information, patient demographics, surgical techniques, rates of complication and conversion to TKA, patient-reported outcome scores, RTS, and RTW were extracted. Data were synthesized, and a random effects meta-analysis of proportions using continuity correction methods was performed to determine the proportion of patients receiving opening and closing wedge PTO who experienced adverse events. Results: The review and meta-analysis included 33 studies involving 1914 patients who underwent PTO with a weighted mean ± SD age of 50.3 ± 9.9 years and body mass index of 26.9 ± 2.3 kg/m2. The pooled RTS and RTW rates were 75.7% (range, 55%-100%) in 814 patients and 80.8% (range, 41%-100%) in 505 patients, respectively. The pooled TKA rate was 12.5% (range, 0%-35.7%) at a mean of 70.6 months and the pooled complication rate was 11.1% (range, 0%-28.6%). The overall random pooled summary estimate of the proportion of patients who underwent opening wedge PTO and subsequently converted to TKA was 2.0% (95% CI, 1.0%-4.0%; I2 = 63.65) at a mean of 43.4 ± 31.9 months and who experienced a complication was 6.0% (95% CI, 3.0%-9.0%; I2 = 87.10%). For closing wedge PTO, the proportion of patients who converted to TKA was 5.0% (95% CI, 1.0%-9.0%; I2 = 93.1%) and experienced a complication was 2.0% (95% CI, 1.0%-3.0%; I2 = 90.0%). Only 53.8% of studies that referenced RTS provided postoperative RTS rates, and 80% of studies that referenced RTW provided RTW rates. Only 1 study defined RTS criteria, no studies defined RTW criteria, and 31 different outcome measures were reported across all studies. Conclusion: Patients undergoing PTO for osteoarthritis, cartilage defects, and symptomatic malalignment of the knee experience high rates of RTS and RTW. These patients also experience low rates of complications and conversion to TKA, regardless of opening or closing wedge technique. Significant heterogeneity exists with regard to criteria used to define RTS and RTW and patient-reported outcome measures used to assess clinical and functional improvements after PTO.

Hinge Fractures Are Underestimated on Plain Radiographs After Open Wedge Proximal Tibial Osteotomy: Evaluation by Computed Tomography

Background: Lateral hinge fracture (LHF) after medial open wedge high tibial osteotomy (MOWHTO) may not be recognized on perioperative plain radiographs. Such cases may be identified at follow-up and misdiagnosed as delayed LHF. Purpose: This study aimed to investigate the extent of LHF misdiagnosis and to determine whether patients with LHFs have inferior clinical outcomes after MOWHTO. Study Design: Case series; Level of evidence, 4. Methods: Fifty-one knees in 50 patients (36 women, 14 men; mean age, 51.8 years; range, 24-64 years) who had undergone MOWHTO with locking plate fixation between October 2013 and April 2016 were retrospectively reviewed. LHFs identified on intraoperative fluoroscopy and immediate postoperative radiographs were compared with the actual incidence based on computed tomography (CT) scans performed within 2 days of surgery. Delayed LHFs, not visible on the CT scans but found on later follow-up radiographs, were also assessed. More frequent radiographic check-ups were recommended in patients with LHFs, and weightbearing was delayed until evident callus formation was seen on follow-up radiographs for type 2 or 3 fractures. The loss of correction, the time of union, and complication rate were compared between the knees with LHF and those without LHF. Clinical outcome was measured according to the Knee Society (KS) scores. Results: Overall, 14 early LHFs (27.5%) were identified on CT scans. Of these, 7 LHFs (13.7%) were observed on perioperative radiographs, and the remaining 7 LHFs were identified on later radiographs. Delayed LHFs occurred in 2 cases (3.9%). In the 16 knees with LHF, minimal loss of correction was observed 1 month to 1 year postoperatively without statistical significance. No alignment changes were seen in the 35 knees without LHFs. In the LHF versus no LHF groups, no significant differences were seen regarding time of union (5.3 ± 1.7 months vs 5.4 ± 1.8 months, respectively; P = .898) and postoperative KS scores (knee score, 96.6 ± 2.5 vs 95.3 ± 6.4, P = .435; functional score, 94.4 ± 9.6 vs 89.1 ± 10.9, P = .107). No other complications occurred in either group. Conclusion: Most LHFs after MOWHTO occurred intraoperatively, but half (7/14) were not identified on postoperative radiographs. CT scans would enable detection of early LHFs that would otherwise have been mistaken for delayed LHF. However, clinical outcomes did not differ between patients with and without LHF.

A patellar tendon length conservation method: Biplanar retrotubercle open-wedge proximal tibial osteotomy.

OBJECTIVE:The early-period results of our technique for performing a medial biplanar retrotubercle open-wedge proximal tibial osteotomy for the surgical treatment of varus gonarthrosis were evaluated and compared with those reported in the literature.METHODS:The clinical and radiological results of a medial biplanar retrotubercle open-wedge proximal tibial osteotomy performed on 23 knees in 22 patients with medial gonarthrosis with varus alignment were analyzed.RESULTS:Twenty patients were female and 2 were male. At the time of surgery, the mean age was 56.22 years (44–66 years), the mean body mass index was 31.95 kg/m2 (23.4–44.9 kg/m2), and the mean Hospital for Special Surgery (HSS) score was 68.7 (48–83). The mean preoperative femorotibial anatomical axis angle was 186.39° (173–194°), and the mean Insall-Salvati index value was 1.04 (0.94–1.171). The mean length of follow-up was 30.19 months (6–42 months). At the last follow-up examination, the mean HSS score was 86.48 (74–100), the mean femorotibial anatomical axis angle was 175° (168–171°), and the mean Insall-Salvati index value was 1.06 (0.857–1.32). Comparison of the final follow-up values with the preoperative values demonstrated significant improvement in the HSS score and femorotibial anatomical axis angle, but no significant difference in the Insall-Salvati index value.CONCLUSION:The results of this study indicated that frontal and sagittal plane deformities in patients with varus gonarthrosis can be treated with biplanar retrotubercle open-wedge proximal tibial osteotomy with good clinical results that achieve patellar tendon length stability and avoid patellofemoral problems.

Posteromedially placed plates with anterior staple reinforcement are not successful in decreasing tibial slope in opening-wedge proximal tibial osteotomy.

To document the effectiveness of a novel technique to decrease tibial slope in patients who underwent a proximal opening-wedge osteotomy with an anteriorly sloped plate placed in a posteromedial position. The hypothesis was that posteromedial placement of an anteriorly sloped osteotomy plate with an adjunctive anterior bone staple on the tibia would decrease, and maintain, the tibial slope correction at a minimum of 6months following the osteotomy. All patients who underwent biplanar medial opening-wedge proximal tibial osteotomy with anterior staple augmentation to decrease sagittal plane tibial slope were included, and data were collected prospectively and reviewed retrospectively. Indications for decreasing tibial slope included medial compartment osteoarthritis with at least one of the following: ACL deficiency, posterior meniscus deficiency, or flexion contracture. Preoperative, immediate postoperative, and 6-month postoperative radiographs were reviewed. Twenty-one patients (14 males and 7 females) were included in the study with a mean age of 36.5years. Intrarater and interrater reliability of slope measurements were excellent at all time points (ICC≥0.94, ICC≥0.85). The osteotomy resulted in an average tibial slope decrease of 0.8 from preoperative (n.s.). At 6-month postoperative, average slope was not significantly different from time-zero postoperative slope (mean=+0.2°). The most important finding of this study was that posteromedial placement of an anteriorly angled osteotomy plate augmented with an anterior staple during a biplanar medial opening-wedge proximal tibial osteotomy did not decrease sagittal plane tibial slope. Whether a staple was effective in maintaining tibial slope from time zero to 6months postoperatively was unable to be assessed due to no significant change in tibial slope from the preoperative postoperative states. The results of this study note that current osteotomy plate designs and surgical techniques are not effective in decreasing sagittal plane tibial slope. IV.

Medial Opening Wedge Proximal Tibial Osteotomy

Genu varus malalignment can lead to medial compartment overload and progression of ipsilateral compartment osteoarthritis. To slow this process, a medial opening wedge proximal tibial osteotomy (PTO) can be performed. This type of PTO is indicated in patients with genu varus malalignment and isolated medial compartment osteoarthritis of the knee, prior to or concurrent with medial compartment cartilage procedures or meniscal transplants, chronic posterolateral corner deficiency, or chronic anterior cruciate ligament deficiency. When treating ligamentous instability, a PTO can be performed in isolation, with simultaneous ligament reconstruction, or as a staged procedure with the osteotomy first, followed by ligament reconstruction if instability persists. Failure to address malalignment in cases of concurrent ligament reconstruction leads to increased stress on the graft and potential graft failure. One distinct advantage of this procedure is the ability to correct deformities in the sagittal and coronal planes. The purpose of this article was to describe our technique used to perform a medial opening wedge PTO.

Opening-Wedge Proximal Tibial Osteotomy

Varus knee malalignment caused by medial compartment arthritis results in progressive asymmetric wear of the tibiofemoral joint. This wear can cause progressively painful gonarthrosis. Surgical methods to address varus knee malalignment include lateral closing-wedge proximal tibial osteotomy, medial opening-wedge osteotomy, and arthroplasty. Medial opening-wedge proximal tibial osteotomy is an effective procedure for restoring proper coronal alignment and reducing knee pain. In this technical note, we present a reproducible technique for proximal tibial osteotomy.

Changes in posterior tibial slope angle in patients undergoing open-wedge high tibial osteotomy for varus gonarthrosis.

In this study, postoperative changes in the posterior tibial slope angle and clinical outcomes following open-wedge high tibial osteotomy were evaluated. This study included 39 knees (18 left, 21 right) of 35 patients (three male, 32 female; median age, 53years; age range 37-64years) with symptomatic isolated medial joint osteoarthritis who underwent open-wedge high tibial osteotomy and fixation with a Puddu plate. The patients were clinically assessed according to the Lysholm knee score, a visual analogue pain scale, and a patient satisfaction questionnaire. Radiological assessment was made according to the changes in the posterior tibial slope angle and the correlation between these changes and clinical signs. The median follow-up period was 11years (range 7-14years). Significant improvements were observed in the preoperative and postoperative clinical scores of the Lysholm knee scale, visual analogue pain scale, and patient satisfaction questionnaire (p<0.05). Radiological assessment showed that the posterior tibial slope angle was significantly higher during the postoperative and follow-up periods (p0.05). There was no correlation between the postoperative Lysholm scores and the increase in the posterior tibial slope angle (p=n.s.). We conclude that both the conventional Puddu plate design and its anteromedial plate placement are what increase the tibial slope after an opening-wedge proximal tibial osteotomy. Therefore, current new plate design may help preserve the posterior tibial slope angle. IV.

Does Open Wedge Proximal Tibial Osteotomy Really Affect Tibial Slope and Patellar Height?

Objectives:Open wedge proximal tibial osteotomy has gained popularity over recent years. This technique has several advantages over lateral closed wedge osteotomy, like lack of any need for fibular osteotomy and freedom from peroneal nerve complications, easier and more precise correction, no limb shortening and easier access for an eventual total knee arthroplasty. However it was been shown that open wedge osteotomy may reduce patellar height and increase sagittal tibial slope which can cause patellofemoral problems. The aim of the study was to evaluate the alterations in the angle of posterior slope of the tibia and the degree of patellar height following medial opening wedge proximal tibial osteotomy in our patients.Methods:26 females and 7 males, with a mean age of 48, who underwent medial opening wedge proximal tibial osteotomy were included in the study. In all cases, the preoperative measured varus angle was overcorrected to between 5-8° valgus. The posterior slope of the tibia was determined by the proximal tibial anatomical axis and patellar height was measured retrospectively by the Caton index on the pre- and postoperative radiograms at the end of the second month.Results:Preoperatively, on the standing orthoroentgenograms, the mean mechanical axis deviation was 12,36° (8-20) and the mean posterior tibial slope in the sagittal view was 16,24° (10-23). The mean postoperative tibial slope was 17,85° (6-25). Using paired samples test, this increase was statistically significant (p=0.049). Preoperative mean Caton index was 1,35 (1,01-1,92) and the postoperative average was 1,73 (1,11-2,76). There was also a statistical significant increase between the pre-and postoperative values (p<0.001) with paired samples test. There was a positive correlation between preoperative mechanical axis deviation and postoperative slope angle (p=0,014) but there was no correlation between preoperative mechanical axis deviation and postoperative patellar height.Conclusion:In conclusion, tibial slope and patellar height are strongly affected by open wedge high tibial osteotomy and this might have an adverse effect on an eventual knee arthroplasty.

Injury risk to extraosseous knee vasculature during osteotomies: a cadaveric study with CT and dissection analysis.

Realignment osteotomies about the knee may be performed as distal femoral or proximal tibial osteotomies; both may be performed either on the medial or lateral sides of the knee, in closing- or opening-wedge fashion. Although rare, injury to neurovascular structures may occur, and the proximity of the vascular structures to the osteotomy saw cuts has been incompletely characterized. We performed a cadaver study to assess the risk of vascular injury in patients undergoing realignment osteotomies by (1) quantifying the distances between osteotomy saw cuts and blood vessels using three-dimensional CT reconstruction after distal femoral and proximal tibial osteotomies; and (2) qualitatively describing the small- and medium-sized vasculature around the knee, to provide the link between the CT analysis and wedge incision measures, and better show the potential extraosseous supply to the regions investigated. Twelve human cadaveric knees were injected with a latex and barium sulfate suspension into the superficial femoral artery. Each specimen underwent CT to evaluate vascular perfusion and was randomized to either a lateral opening-wedge distal femoral osteotomy and medial opening-wedge proximal tibial osteotomy group, or a medial closing-wedge distal femoral osteotomy and lateral closing-wedge proximal tibial osteotomy group. Postoperatively, knees underwent CT in extension to measure the shortest distance between the osteotomies and the popliteal artery, anterior and posterior tibial arteries, and genicular arteries. Vessels between 5 mm and 10 mm from the osteotomy cut were considered in a zone of moderate risk for damage, while vessels less than 5 mm from the cut were considered in a zone of high risk for damage. Vessels more than 10 mm from the cut were not considered to be at risk. Subsequently, knees underwent dissection and chemical débridement to qualitatively describe the smaller vessels. This part of the study added visual information and gave a comprehensive overview of the vessels at risk. All variations of the osteotomies put at least one artery at risk. The popliteal artery was found in a risk zone for injury in two specimens during closing-wedge distal femoral osteotomy (median distance, 11.6 mm; range, 5.2-14.6 mm). The superior lateral genicular artery was in a risk zone in all the specimens during opening-wedge distal femoral osteotomy (median distance, 3.0 mm; range, 0.7-6.5 mm), and in five specimens during closing-wedge distal femoral osteotomy (median distance, 4.5 mm; range, 1.3-11.2 mm). A concomitant risk for superior medial genicular artery injury was observed in five specimens during opening-wedge distal femoral osteotomy (median distance, 8.7 mm; range, 0.8-13.9 mm) and in four specimens during closing-wedge distal femoral osteotomy (median distance, 4.1; range, 0.5-41.7 mm). The popliteal artery was in a risk zone in four specimens during opening-wedge proximal tibial osteotomy (median distance, 9.6 mm; range, 6.6-12.9 mm), and in three specimens during closing wedge proximal tibial osteotomy (median distance, 9.6 mm; range, 4.4-11 mm). The inferior medial genicular artery could be classified at risk in five specimens during opening-wedge proximal tibial osteotomy (median distance, 2.1 mm; range, 0.3-32 mm) and in five specimens during closing-wedge proximal tibial osteotomy (median distance, 5.8 mm; range, 1.4-13 mm). Furthermore, the inferior lateral genicular artery was found in a risk zone in two specimens of closing-wedge proximal tibial osteotomies (median distance, 17.4 mm; range, 8-23.3 mm). There were no differences between opening-wedge and closing-wedge distal femoral osteotomies and proximal tibial osteotomies in the vessels at risk during the procedure. After chemical débridement, knees showed abundant vascularization of the distal femur and lateral tibia, whereas the medial tibia contained few arteries. With the numbers available, we found that none of the osteotomy techniques performed was safer than any other in terms of the proximity of the major arterial structures and some vessels appear to be at relatively high risk during these procedures. This study clarifies that the genicular arteries on the opposite side of the surgical field, which cannot be seen and protected during the procedure, can be at risk of injury, particularly when the cortical hinge is compromised. Additional studies are necessary to address the potential risk of the dissection needed for plate placement and injuries related to drilling and screw placement during osteotomies around the knee.

Does proximal tibial osteotomy with a novel osteotomy system obtain coronal plane correction without affecting tibial slope and patellar height?

To determine changes in tibial slope, patellar height, and coronal plane alignment after medial opening wedge proximal tibial osteotomy (PTO) using a modern osteotomy system. Patients undergoing medial opening wedge PTO for any indication with follow-up until radiographic union were identified. Pre- and post-operative tibial slope (referenced off the anterior tibial cortex, proximal tibial anatomic axis, and posterior tibial cortex), patellar height (Caton-Deschamps, Blackburne-Peel, and Insall-Salvati indices), and coronal plane [mechanical axis and weight-bearing line (WBL) ratio] measurements were taken by two observers and compared. Review of 27 patients demonstrated unchanged tibial slope and slightly decreased patellar height post-operatively (Caton-Deschamps: -0.10 ± 0.09; Blackburne-Peel: -0.11 ± 0.10). Coronal plane measurements showed 6.4° ± 1.8° mean change in mechanical axis. Mean post-operative WBL ratio was significantly lower (51.6 ± 11.5 %) than mean goal WBL ratio (62.2 ± 2.5 %). Preoperative mechanical axis >6° varus and osteoarthritis alone as the surgical indication were risk factors for undercorrection >10 %. Medial opening wedge PTO using a recently developed instrumentation system was found to have no effect on tibial slope. Patellar height was decreased after osteotomy using this system, although clinical significance of these findings is unknown. Coronal plane undercorrection of 10.6 % of the target WBL ratio was seen in the group as a whole, although secondary analysis of these results indicated that patients with medial compartment osteoarthritis and/or preoperative mechanical axis of >6° varus accounted for the majority of the cases of undercorrection. Retrospective case series, Level IV.

Corrective tibial osteotomy in young adults using an intramedullary nail.

PurposeThe purpose of this study was to document results of a less invasive technique of open wedge proximal tibial osteotomy (PTO) for the varus knee in young adults using an intramedullary tibial nail.Materials and MethodsWe prospectively studied 24 knees in 16 young patients with varus knee deformity. The mean follow-up was 54 months (range, 36 to 107 months) and the mean age of patients at the time of operation was 25.8 years (range, 18 to 40 years). The open wedge PTO was performed below tibial tuberosity using a percutaneous multiple drill-hole technique. Conventional intramedullary tibial nail was used for fixation without bone graft. Radiographic evaluations were made using mechanical alignment (MA), posterior tibial slope angle, and Insall-Salvati ratio. Union time, loss of correction, implant failure, and associated complications were also investigated.ResultsThe mean MA was significantly changed from -9.7° preoperatively to 1.1° at the final follow-up (p<0.001). There was no significant change in the proximal tibial anatomy and patellar height. All patients achieved radiographic bony union at an average of 3.1 months without loss of correction. The only complication was knee pain due to nail prominence in 3 patients.ConclusionsRadiographic evaluation indicated that PTO using an intramedullary tibial nail leads to significant improvement in radiographic parameters without changes in posterior tibial slope or patellar height. We found that this technique could be a less invasive and effective alternative for correction of the varus knee in young adults.

The Effect of Medial Opening Wedge Proximal Tibial Osteotomy on Patellofemoral Contact

Background: It has been suggested that patellofemoral contact pressures and contact forces may be altered secondary to an opening wedge high tibial osteotomy, yet few data are available that quantify the effect of varying degrees of medial opening wedge osteotomy on the patellofemoral joint contact characteristics. Hypothesis: Opening wedge medial proximal tibial osteotomy will increase patellofemoral contact force and pressure. Study Design: Controlled laboratory study. Methods: Nine human cadaver knees were used. Pressure-sensitive film was placed in the suprapatellar pouch, leaving the patellar tendon and medial and lateral retinacula intact. The quadriceps tendon was attached to a materials testing machine along the axis of the femur, whereby a pulley mechanism generated 950 N of force. Patellofemoral contact characteristics were measured with pressure-sensitive film at 30°, 60°, 90°, and 120° of flexion for the native knee and after subsequent 10-mm and 15-mm medial opening wedge proximal tibial osteotomies. The film was analyzed with imaging software. Results: There was a statistically significant increase (P < .05) in mean contact pressure at 30° and 120° between the 10-mm osteotomy and native knee and across all flexion angles between the 15-mm osteotomy and native knee. Furthermore, a significant difference was seen in peak pressures when native knees were compared with 10-mm and 15-mm opening wedge osteotomies at all flexion angles. Conclusion: There was a significant increase in patellofemoral pressures at varying degrees of knee flexion after medial opening wedge proximal tibial osteotomies of only 10 mm; a larger osteotomy resulted in a greater increase. Clinical Relevance: When performing a medial opening wedge proximal tibial osteotomy, the surgeon should consider the negative effects of increased patellofemoral peak pressure.

Treatment for painful bone marrow edema by open wedge tibial osteotomy

We evaluated the results of patients who had undergone medial open wedge proximal tibial osteotomy, with painful bone marrow edema in the medial tibial plateau. The study included 21 patients who had presented with knee pain and whose MRIs showed bone marrow edema in medial plateau. The degree of osteoarthritis was evaluated radiologically according to the Kellgren-Lawrence criteria; 6 cases were Grade 1, 11 cases were Grade 2, and 3 cases were Grade 3. Preoperative varus angle was a mean of 2.19° (0-4). The bone marrow edema was classified according to the width of the lesions extending into the joint surface subchondral area on MRI T2 sequences. Open wedge osteotomy was performed in all patients. The postoperative results were evaluated by X-ray, MRI, and WOMAC (Western Ontario and McMaster Universities) knee scores. The preoperative 2.19° varus angle was evaluated postoperatively as valgus 6.57° (4-8°) (p < 0.05). The postoperative WOMAC knee scores revealed a significant decrease in pain (p < 0.05). In conclusion, we are of the opinion that medial open wedge proximal tibial osteotomy is an effective treatment in patients who have painful bone marrow edema in medial tibia plateau.

Monoplanar versus biplanar medial open-wedge proximal tibial osteotomy for varus gonarthrosis: a comparison of clinical and radiological outcomes

We compared clinical and radiological results of two proximal tibial osteotomy (PTO) techniques: monoplanar medial open-wedge osteotomy and biplanar retrotubercle medial open-wedge osteotomy, stabilised by a wedged plate. We evaluated 88 knees in 78 patients. Monoplanar medial open-wedge PTO was performed on 56 knees in 50 patients with a mean age of 55 ± 9 years. Biplanar retrotubercle medial open-wedge PTO was performed on 32 knees in 28 patients with a mean age of 57 ± 7 years. Mean follow-up periods were 40.6 ± 7 months for the monoplanar PTO group and 38 ± 5 months for the biplanar retrotubercle PTO group. Clinical outcome was evaluated using the hospital for special surgery scoring system, and radiological outcome was evaluated by the measurements of femorotibial angle (FTA), patellar height and tibial slope changes. In both groups, post-operative HSS scores increased significantly. No significant difference was found between groups in FTA alteration, but the FTA decreased significantly in both groups. Patellar index ratios decreased significantly in the monoplanar PTO group (Insall-Salvati Index by 0.07, Blackburne-Peel Index by 0.07), but not in the biplanar retrotubercle PTO group. Tibial slopes were increased significantly in the monoplanar PTO group, but not in the retrotubercle PTO group. Biplanar retrotubercle medial open-wedge osteotomy and monoplanar medial open-wedge osteotomy are both clinically effective for the treatment for varus gonarthrosis. Retrotubercle osteotomy also prevents patella infera and tibial slope changes radiologically.