Patellar height modification after high tibial osteotomy by either medial opening-wedge or lateral closing-wedge osteotomies

Surgical strategy and complication management of osteotomy around the painful degenerative varus knee: ESSKA Formal Consensus Part II

PURPOSE

The purpose of the European consensus was to provide recommendations for the treatment of patients with a painful degenerative varus knee using a joint preservation approach. Part II focused on surgery, rehabilitation and complications after tibial or femoral correction osteotomy.

METHODS

Ninety-four orthopaedic surgeons from 24 countries across Europe were involved in the consensus, which focused on osteotomies around the knee. The consensus was performed according to the European Society for Sports Traumatology, Knee Surgery and Arthroscopy consensus methodology. The steering group designed the questions and prepared the statements based on the experience of the experts and the evidence of the literature. The statements were evaluated by the ratings of the peer-review groups before a final consensus was released.

RESULTS

The ideal hinge position for medial opening wedge high tibial osteotomy (MOW HTO) should be at the upper level of the proximal tibiofibular joint, and for lateral closing wedge distal femoral osteotomy (LCW DFO) just above the medial femoral condyle. Hinge protection is not mandatory. Biplanar osteotomy cuts provide more stability and quicker bony union for both MOW HTO and LCW DFO and are especially recommended for the latter. Osteotomy gap filling is not mandatory, unless structural augmentation for stability is required. Patient-specific instrumentation should be reserved for complex cases by experienced hands. Early full weight-bearing can be adopted after osteotomy, regardless of the technique. However, extra caution should be exercised in DFO patients. Osteotomy patients should return to sports within 6 months.

CONCLUSION

Clear recommendations for surgical strategy, rehabilitation and complications of knee osteotomies for the painful degenerative varus knee were demonstrated. In Part 2 of the consensus, high levels of agreement were reached by experts throughout Europe, under variable working conditions. Where science is limited, the collated expertise of the collaborators aimed at providing guidance for orthopaedic surgeons developing an interest in the field and highlighting areas for potential future research.

LEVEL OF EVIDENCE

Level II, consensus.

The Influence of Tibial Tubercle-Sparing Slope-Reducing Osteotomy on Patellar Height in Patients Undergoing Revision ACL Reconstruction

BACKGROUND

A posterior tibial slope (PTS) >12° is an independent risk factor for anterior cruciate ligament (ACL) graft rupture, and a high tibial osteotomy (HTO) for slope correction can help avoid it. Management of patellar height is of major concern when performing HTO.

PURPOSE

To evaluate the effect of tibial tubercle-sparing anterior closing-wedge osteotomy on patellar height in revision ACL reconstruction (ACLR).

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients who underwent arthroscopic revision ACLR combined with retro-tibial tubercle anterior closing-wedge HTO (ACW-HTO) between January 1, 2016, and March 31, 2021, were assessed for eligibility. Patellar height was measured on full weightbearing lateral radiographs according to the Insall-Salvati index (ISI) and Caton-Deschamps index (CDI) or frontal radiographs using the femoral patellar height index. The PTS was evaluated using the proximal anatomic axis of the tibia on standard short lateral radiographs. The delta (postoperative - preoperative) and the ratio (preoperative/postoperative) of the 3 patellar height indices and PTS were calculated. Preoperative and postoperative patellar heights were compared using independent t tests for each index. Also investigated was whether patients changed patellar height category (baja, normal, or alta) after slope osteotomy.

RESULTS

Among 475 revision ACLRs, 47 tibial tubercle-sparing ACW-HTOs were retained for analysis. No significant difference in patellar height was found between pre- and postoperative radiographs regardless of the index (preoperative - postoperative) (ISI: 1.0 ± 0.2 - 0.9 ± 0.2, P = .1729; CDI: 1.0 ± 0.2 - 1.0 ± 0.2, P = .4034; femoral patellar height index: 1.5 ± 0.2 - 1.5 ± 0.2; P = .5130). Fifteen patients (31.9%) exhibited a postoperative change in their patellar height category when measured by the ISI (6 moved up a category, 9 moved down one), and 18 patients (38.3%) changed category according to the CDI (10 moved up a category, 8 moved down one). No significant difference was found between pre- and postoperative patellar height among these patients (ISI: P = .2418; CDI: P = .3005).

CONCLUSION

Changes in patellar height ratio are common after tibial tubercle-sparing ACW-HTO in patients undergoing revision ACLR. The clinical effect of these changes is unknown, and further study is needed to investigate whether they may result in patellofemoral symptoms.

Radiographic Investigation of Coronal Plane and Patellar Height and Changes Following Tibial Deflection Osteotomy for Correction of Tibial Slope in Combination With ACL Reconstruction

BACKGROUND

A tibial deflexion osteotomy (TDO) is performed to decrease the sagittal tibial slope to reduce the relative risk of anterior cruciate ligament (ACL) reconstruction (ACLR) graft failure. Given that coronal plane osteotomies can cause consequential changes in the sagittal plane to patellar height and tibial slope, potential changes to coronal plane alignment and patellar height can result after a sagittal plane osteotomy.

PURPOSE

To compare preoperative and postoperative coronal plane alignment after TDO, as well as to analyze the effect of the osteotomy on patellar height.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

This study was conducted on a consecutive series of patients with primary and revision ACLR with concomitant TDO between 2011 and 2022. Inclusion criteria were 1-stage autograft ACLR combined with supratubercular TDO with pre- and 3 months postoperative radiographs of sufficient quality. Indications for TDO were anterior instability requiring ACL revision surgery and a posterior tibial slope (PTS) >9° or a PTS >14° in the primary ACL surgery patients. Anteroposterior and lateral knee radiographs were reviewed, and the medial proximal tibial angle (MPTA), PTS, Caton-Deschamps index (CDI), and modified Insall-Salvati ratio were measured directly from the radiographs by 2 independent reviewers.

RESULTS

A total of 68 patients were included in this study. Pre- and postoperative radiographs were performed 1 month before and 3 months after surgery, respectively. There was a significant increase in the mean MPTA of 0.95° varus (SD, 2.1°; range, increase of 4.23° valgus to increase of 7.74° varus; P < .01), a decreased PTS of 8.86° (SD, 3.03°; P < .01), and an increased CDI of 0.08 (range, decrease of 0.27 to increase of 0.64) (P < .01; SD, 0.17) in patients undergoing TDO. Insall-Salvati ratio measurements showed no difference. There was good intra- and interobserver reliability, with intraclass correlation coefficients of 0.97 and 0.91 for MPTA, 0.97 and 0.87 for PTS, 0.87 and 0.93 for CDI, and 0.88 and 0.76 the Insall-Salvati ratio.

CONCLUSION

This study, the largest series on TDO for ACLR, demonstrates that the TDO can be performed safely without large changes to coronal alignment or patellar height. The tibial slope was reduced by a mean of 8.86° (range, 2.3°-11.5°; P < .01). The TDO produces a small statistically significant change to coronal alignment, inducing a mean increased varus of <1° and an increased patellar height of 0.1 CDI. Therefore, TDO can be performed safely without dramatic changes to coronal alignment or patellar height, this study highlights technical aspects to minimize iatrogenic varus.

Maintaining Posterior Tibial Slope and Patellar Height During Medial Opening Wedge High Tibial Osteotomy

BACKGROUND

Increased posterior tibial slope (PTS) and decreased patellar height (PH) after medial opening wedge high tibial osteotomy (MOWHTO) have been repeatedly reported in the literature. However, this has been disputed in more recent biomechanical studies.

HYPOTHESIS

No change in PTS or PH would result after MOWHTO with the freehand technique, regardless of the degree of the coronal plane correction.

STUDY DESIGN

Case series.

METHODS

A total of 62 patients who underwent MOWHTO between 2018 and 2020 were included. Surgery was performed using a dedicated step-by-step protocol to reduce the risk of unintentional slope changes. All patients were evaluated preoperatively and at a 2-year follow-up with the Knee injury and Osteoarthritis Outcome Score and the University of California, Los Angeles physical activity scale. Pre- and postoperative radiographic lower limb alignment parameters-including hip-knee-ankle angle (HKA), medial proximal tibial angle (MPTA), mechanical lateral distal femoral angle, proximal posterior tibial angle (PPTA), joint line convergence angle, and joint line obliquity-were measured on full-length lower limb radiographs. PH measurements assessed on lateral and anteroposterior knee radiographs included the Caton-Deschamps, Insall-Salvati, and Schröter indices.

RESULTS

A significant change was observed in the coronal plane alignment, with an increase in the MPTA from 84.38° to 90.39° (P < .001) and a consequent increase in the HKA from 172.19° to 180.15° (P < .001). No significant changes were observed in the PTS, as evidenced by a postoperative PPTA of 80.6° versus a preoperative value of 80.4° (P = .2). No significant changes were detected in the mean PH on all 3 indices used-pre- versus postoperative Caton-Deschamps, Insall-Salvati, and Schröter indices measured 0.95 versus 0.93 (P = .2), 1.03 versus 1.03 (P = .5), and 1.56 versus 1.54 (P = .3), respectively.

CONCLUSION

In this study, MOWHTO did not result in significant changes in the PTS or PH when accurate preoperative planning and precise intraoperative freehand technique were adopted..

Open wedge high tibial osteotomy does not decrease patellar height relative to femur: A three-dimensional computer model analysis

BACKGROUND

Patellar height, which decreases after open wedge high tibial osteotomy (OWHTO), has conventionally been assessed by tibial references using lateral radiographs of the knee; however, changes in the proximal tibia shape after OWHTO may affect this method. We aimed to evaluate the changes in patellar height position relative to the transepicondylar axis of the femur after OWHTO using in vivo three-dimensional (3D) computer models.

METHODS

Fourteen patients who underwent 3D magnetic resonance imaging (MRI) at 30° and 50° knee flexion before OWHTO and after hardware removal were included. 3D computer models of the knee were created from the MRI scans and superimposed over the images taken in each position using voxel-based registration. For patellar height evaluation, a patellar reference point was established at each flexion angle and the femoral condylar planes (FCP) were set, including the transepicondylar axis. The patellar center angle was defined as the angle between an FCP that included the top of the intercondylar notch and an FCP that included the patellar reference point. The patellar center angle was evaluated at 30° and 50° knee flexion before and after OWHTO.

RESULTS

The patellar center angle at 30° and 50° knee flexion did not significantly decrease after OWHTO, whereas the Caton-Deschamps index and Blackburne-Peel index based on tibia-referenced measurements significantly decreased postoperatively.

CONCLUSION

Patellar height position relative to the femur in the 3D computer model did not decrease after OWHTO, whereas tibia-referenced conventional radiographic measurements significantly decreased. When evaluating patellar height, characteristics of each parameter should be considered.

Excellent short-term results of dome-shaped high tibial osteotomy combined with all-inside anterior cruciate ligament reconstruction

PURPOSE

This study aimed to evaluate short-term outcomes at least 2 years after dome-shaped high tibial osteotomy (HTO) combined with all-inside anterior cruciate ligament reconstruction (ACL) in patients with persistent ACL insufficiency accompanied by pain due to varus deformity.

METHODS

The study enrolled 19 knees of 18 patients. The mean age was 58.4 ± 13.4 years and the mean postoperative follow-up period was 31.4 ± 6.6 months (24-49 months). JOA(Japanese Orthopaedic Association)-OA(osteoarthritis) score, Lysholm score, radiographic outcomes such as femoro-tibia angle (FTA) in a standing position, side-to-side difference in KT-1000 measurements were evaluated at pre op. and post operative final follow up. And arthroscopic evaluation was evaluated at the time of the HTO plate-removal procedure.

RESULTS

Before surgery, the mean JOA-OA score was 65.0 ± 13.5, the mean Lysholm score was 47.2 ± 16.2, the mean femoro-tibia angle (FTA) in a standing position was 183.8 ± 3.4° (range;180-190°), and the mean side-to-side difference in KT-1000 measurements was 4.1 ± 1.3 mm. After surgery, the mean JOA-OA score, Lysholm score, and side-to-side difference in KT-1000 measurements improved to 93.1 ± 6.0 (P < 0.00001), 94.2 ± 5.9 (P < 0.00001), and -0.2 ± 0.8 mm (P < 0.00001), respectively. The mean FTA decreased to 168.0 ± 3.3 (P < 0.00001), and the mean posterior tibial slope angle decreased to 5.0 ± 3.6° from 6.9 ± 2.6° preoperatively (P = 0.024). Arthroscopic evaluation during the HTO plate-removal procedure of 17 knees were performed at a mean of 16 months after the surgery. The reconstructed ACL graft in 13 knees were successful, a cyclops lesion in one knee, and looseness of the graft in three knees.

CONCLUSIONS

Dome-shaped HTO allows for a relatively high degree of varus correction and decreases the steep posterior tibial slope that causes excessive load on the ACL. Therefore, its use in combination with ACL reconstruction seems to be effective.

Proximal tibia osteotomy with absorbable spacer combined with fibular osteotomy versus high tibial osteotomy for medial compartmental knee osteoarthritis

PURPOSE

The study aimed to compare the perioperative complications, short-term clinical outcomes, patient-reported outcomes, and radiographic parameters of tibiofibular proximal osteotomy combined with absorbable spacer insertion (TPOASI) and open-wedge high tibial osteotomy (OWHTO) in a two year postoperative time period.

METHODS

A total of 160 patients with Kellgren-Lawrence classification grade 3 medial compartmental knee OA were randomized to receive either TPOASI (n = 82) or OWHTO (n = 78). The primary and secondary outcomes were measured preoperatively, postoperatively, and at each follow-up examination. The primary outcomes were the between-group change in the Western Ontario and McMaster Universities Global score (WOMAC). Secondary measures included visual analog scale (VAS), radiographic parameters, American Knee Society Score (KSS), operation time, blood loss, length of incision, hospital stay, and relevant complications. Postoperative radiographic parameters, including the femorotibial angle (FTA), varus angle (VA), and joint line convergence angle (JLCA), were measured to evaluate the correction of varus deformity.

RESULTS

No significant differences were found in the baseline data between the two groups. Both methods improved functional status and pain postoperatively. For primary outcomes of both groups, statistical difference was observed in WOMAC scores at the 6-month follow-up (P < 0.001). For secondary outcomes, no statistical difference was observed between the groups during the 2-year follow-up (P > 0.05). For TPOASI vs. OWHTO, the mean hospital stay (6.6 ± 1.3 days vs. 7.8 ± 2.1 days) was shorter (P < 0.001), and both blood loss (70.56 ± 35.58 vs. 174.00 ± 66.33 mL) and complication rate (3.7% vs. 12.8%) were significantly lower (P < 0.005 for both).

CONCLUSIONS

Both approaches showed satisfactory functional outcomes and alleviated pain. However, TPOASI is a simple, feasible method with few complications, and it could be widely used.

The effects of open wedge high tibial osteotomy for knee osteoarthritis on the patellofemoral joint. A systematic review

BACKGROUND (INCLUDING AIMS OF THE STUDY)

To investigate the impact medial opening wedge high tibial osteotomy (MOWHTO) has on the progression of patellofemoral (PF) OA, patella height, contact pressure within the PF joint and clinical outcomes.

METHODS

A systematic review was conducted in January 2022 according to PRISMA guidelines. The ICRS cartilage grade of the PF joint at the initial MOWHTO surgery and at second look surgery was compared and relative risk of progression of PF OA was calculated. Evaluation of patella height was assessed by Caton-Deschamps index, Blackburne-Peel index or Insall-Salvati index pre and post MOWHTO. Cadaveric studies assessing contact pressures in the PF after MOWHTO were included.

RESULTS

Forty-two studies comparing 2419 patients were included. The mean age was 53.1 years (16-84), 61.3% female. The risk of progression of PF OA was highest in the uniplanar and biplanar MOWHTO with proximal tubercle osteotomy groups (RR = 1.28-1.51) compared to biplanar MOHWTO with distal tubercle osteotomy (RR = 0.96-1.04). Patella height was not affected after biplanar MOWHTO with distal tubercle osteotomy (p < 0.001). Cadaveric studies demonstrate that PF contact pressures increase with more severe corrections (15°) but suggest biplanar MWOHTO and distal tubercle osteotomy induces lower contact pressures within the PF joint than other MOWHTO techniques. Significant over correction is associated with worse clinical outcomes and anterior knee pain.

CONCLUSION

Biplanar MOWHTO and distal tubercle osteotomy has minimal effect on the contact pressures in the PF joint resulting in less severe progression of PF OA and has minimal impact on patella height.

Precise Patellar Tendon Insertion Protection and Osteotomy Surface Advantage of Transtibial Tuberosity-High Tibial Osteotomy

OBJECTIVE

Medial opening wedge high tibial osteotomy (HTO) is successful in the treatment of knee osteoarthritis with medial compartment stenosis and tibial varus deformity, but patella infera is the main complication. This study aims to design a new medial tibial open osteotomy scheme, transtibial tuberosity-high tibial osteotomy (TT-HTO), which can fully protect the patellar tendon insertion. In addition, the area of the osteotomy surface and wedge volume were evaluated in TT-HTO, biplanar distal tibial tuberosity osteotomy (biplanar-DTO), and uniplanar-DTO to evaluate the potential advantages of this technology in bone healing.

METHODS

The tibial tubercle was divided into four equal sections from proximal to distal, which were defined as zones A, B, C, and D. From September to December 2020, the imaging examinations of 200 patients (95 males and 105 females) with a mean age of 40.6 years (range 19-60 years) were evaluated to observe the zonation of the tibial tubercle where the insertion of the patellar tendon is located. Then, 59 patients (23 males and 36 females) with a mean age 59.6 years (range 43-77 years), for a total of 69 knees (32 right and 37 left), who underwent routine knee surgery were observed and verified. According to the position of the patellar tendon insertion, TT-HTO was designed. Fifteen tibial sawbones were divided equally into three groups: TT-HTO; biplanar-DTO; and uniplanar-DTO. The total area of the osteotomy surface was compared using the graph paper method. The wedge volume at wedge heights of 10 mm was compared among osteotomy types using the plasticine Archimedes principle. One-way repeated-measures analysis of variance was used to compare the total area of the osteotomy surface and the wedge volume.

RESULTS

The osteotomy line of TT-HTO passes through the boundary point of zones B and C of the tibial tubercle to fully protect the insertion point of the patellar tendon. The total area of the osteotomy surface in TT-HTO and biplanar-DTO was significantly larger than that in uniplanar-DTO (P < 0.05). The wedge volume in uniplanar-DTO was significantly smaller than that in TT-HTO and biplanar-DTO (P < 0.05). No significant differences in the osteotomy surface and the wedge volume were identified between TT-HTO and biplanar-DTO.

CONCLUSION

TT-HTO can protect the patellar tendon insertion and avoid postoperative patella infera. The osteotomy surface is large and located in an area of cancellous bone, which ensures its good healing characteristics.

Patellofemoral Joint after Opening Wedge High Tibial Osteotomy: A Comparative Study of Uniplane versus Biplane Osteotomies

OBJECTIVE

To the best of our knowledge, there has been no comparative study of changes in radiographic parameters in the sagittal plane between biplane opening wedge high tibial osteotomy (OWHTO) with plate fixation and uniplane OWHTO with spacer implantation. The aim of the study was to compare sagittal radiographs between the procedures of biplane and uniplane OWHTOs in patients with genu varum and to investigate the impact on the patellofemoral joint.

METHODS

A retrospective study of 71 patients (58.0 ± 5.0 years of age, 58 females and 13 males) with varus-aligned medial compartment knee osteoarthritis treated with OWHTO was performed during the period from January 2016 to February 2019. Thirty-three patients underwent biplane osteotomy with plate fixation (biplane group), and 38 patients underwent uniplane osteotomy with absorbable wedged spacer fixation (uniplane group). Independent t tests were used to compare the two groups according to the preoperative and postoperative radiographic parameters of hip-knee-ankle (HKA) angle, posterior tibial slope (PTS), tibial tubercle prominence (TTP), Caton-Deschamps (CD) index, and Blackburne-Peel (BP) index. During the last follow-up assessment, patients were asked to rate their patellofemoral joint status using the Samsung Medical Center (SMC) patellofemoral (PF) scoring system. The visual analog scale (VAS) was also used to rate knee joint pain when walking.

RESULTS

There was no significant difference between the two groups in any of the demographic, clinical, or radiological characteristics at baseline (p > 0.05). Comparisons of postoperative sagittal radiographic parameters between patients in the uniplane group and patients in the biplane group showed significant differences in the PTS (13.4° vs 16.6°, t = 4.465, p < 0.001), TTP (9.0 mm vs 4.2 mm, t = 7.950, p < 0.001), and CD index (0.81 vs 0.70, t = 4.035, p < 0.001). At the final follow-up assessment (minimum, 2 years), the SMC PF function score was significantly lower in patients in the uniplane group than in patients in the biplane group (27.8 vs. 32.1, t = 2.458, p = 0.016), but there were no significant differences in the SMC PF pain score or VAS score (p > 0.05).

CONCLUSION

The essential difference in the postoperative sagittal radiographic changes between biplane and uniplane OWHTO was the tibial tubercle prominence, indicating the posterior displacement of the tibial tubercle. Uniplane OWHTO may yield better function of the patellofemoral joint compared to biplane OWHTO.

Changes in patellar baja progress until 3 months after medial open-wedge high tibial osteotomy

PURPOSE

The purpose of this study was to evaluate sequential patellar height changes as well as the factors leading to these changes after medial open-wedge high tibial osteotomy (MOWHTO).

METHODS

The study cohort constituted 37 knees from 36 patients who underwent MOWHTO for varus knee. The Caton-Deschamps index (CDI) for patellar height was measured preoperatively and at 2 weeks and 3, 6, and 12 months postoperatively. The factors related to sequential changes in patellar height were evaluated.

RESULTS

Significant differences were observed between preoperative CDI and postoperative CDI at all time points (p < .05). Two-week postoperative CDI and postoperative CDI at 3,6,12-months was also significantly different (p < .05). The only significant factor for the change in patellar height between preoperative CDI and postoperative CDI at 2-weeks and 12-months was the change in the Δ medial proximal tibial angle (ΔMPTA) (postoperative MPTA-preoperative MPTA). We could not identify the factor that affected the change in patellar height change from 2-weeks postoperatively.

CONCLUSION

The change in patellar height continued sequentially until at least 3 months postoperatively. ΔMPTA was associated with the change in patellar height at 2 weeks postoperatively compared with preoperatively; however, no factors associated with the change in patellar height from 2 weeks postoperatively to 3, 6, and 12-months postoperatively were identified.

Patellar Height after High Tibial Osteotomy of the Distal Tibial Tuberosity: A Retrospective Study of Age Stratification

Objective

To explore the effect of age stratification on patellar height after single-plane high tibial osteotomy of the distal tibial tuberosity (DTT-HTO).

Methods

A retrospective analysis was performed on 110 knee joints undergoing DTT-HTO. Patients were divided into three groups according to age: under 60 years old, 28 cases; 60 to 70 years old, 61 cases; and over 70 years old, 21 cases. All patients were followed up for no less than 12 months, and at each follow-up, short-leg radiographs and whole-leg radiographs were taken. The values of the Caton-Deschamps index (CDI) and Blackburne-Peel index (BPI) of single-short-leg radiographs and the femoral-tibial angle (FTA) and weight-bearing line ratio (WBLR) of whole-leg radiographs were measured before and at the last follow-up. The Lysholm score before and at the last follow-up and the visual analogue scale (VAS) score before and 3 days after surgery and at the last follow-up were calculated. The frequency of classification of the normal-height patella, patella alta, and patella baja before and after surgery was recorded.

Results

There were no significant differences in CDI and BPI preoperatively or postoperatively among the three groups (P > 0.05), and there were no statistically significant differences in FTA and WBLR. There were no significant differences in CDI, BPI, FTA, or WBLR between the three groups before and after the operation (P > 0.05). The Lysholm score increased from 48.84 ± 10.10 before surgery to 91.96 ± 3.082 after surgery (P < 0.05); the VAS score decreased from 8.23 ± 0.99 before surgery to 1.93 ± 0.953 at 3 days after surgery and 1.07 ± 0.53 at the last follow-up (P < 0.01). No significant difference was observed in the incidence of each patellar height classification between the three groups preoperatively and postoperatively.

Conclusion

Patellar height is not influenced by DTT-HTO. The age of patients is not a limiting factor for the selection of this surgical procedure. Without affecting the height of the patella, DTT-HTO can effectively reduce pain in the knee joint, restore the function of the knee joint, and delay the progression of patellar arthritis.

Does arthroscopic patellar denervation with high tibial osteotomy improve anterior knee pain?

PURPOSE

Patellofemoral (PF) joint osteoarthritis (OA) is a major cause of anterior knee pain. Combined PF and medial tibiofemoral (TF) OA is common in older adults. We evaluated the effect of arthroscopic patellar denervation (PD) in patients with combined TF and PFOA after malalignment correction.

METHODS

Forty-five patients [females/males, 27/18; age, 30-59 years (45.5 ± 8.50); mean body mass index, 25.15 ± 3.04 kg/m²] were treated in our department from March 2017 to March 2019. The patients were randomised into 2 groups: group A included 22 patients who underwent open-wedge high tibial osteotomy (OWHTO) and arthroscopic PD and group B included 23 patients who underwent OWHTO without denervation. The effect of denervation was statistically and clinically evaluated using the Knee injury and Osteoarthritis Outcome Score (KOOS) and Kujala (anterior knee pain score) score.

RESULTS

After 24 months, 40 patients were available for the final follow-up. The final values of KOOS and the Kujala score were significantly different between the groups (p < 0.001). For group A, the average KOOS improved from 42.73 to 72.38 (p < 0.001) and the Kujala score improved from 42 to 74.1 (p < 0.001), whereas in group B, the average KOOS improved from 39.22 to 56.84 (p < 0.001) and the Kujala score improved from 39.7 to 56.4 (p < 0.001).

CONCLUSION

Adding arthroscopic PD to OWHTO relieves anterior knee pain in patients with combined TF and PFOA and improves knee joint function and quality of life.

LEVEL OF EVIDENCE

Level I prospective randomised control clinical trial.

Patellar height is not modified after isolated open-wedge high tibial osteotomy without change in posterior tibial slope

INTRODUCTION

Open-wedge high tibial osteotomy (OWHTO) corrects coronal deformity and can impact sagittal parameters such as posterior tibial slope and patellar height. The aim of the present study was to analyze change in patellar height after medial OWHTO with respect to tibial and femoral-referenced indices.

MATERIAL AND METHOD

This single-center retrospective study included 129 patients undergoing isolated posteromedial OWHTO, without change in tibial slope, using patient-specific cutting-guides. Patellar height was assessed on Caton-Deschamps (CD), Insall-Salvati (IS) and Schröter indices. Posterior tibial slope and coronal femoral and tibial angles were also measured. X-rays were taken preoperatively and at 12 months, and analyzed by 2 independent observers.

RESULTS

OWHTO modified the global lower-limb alignment (Δ=6.3±0.95̊, p<0.0001) and the proximal tibial deformity (Δ=7±0.88̊, p<0.0001). Posterior tibial slope and tibial (CD and IS) and femoral (Schröter) patellar height indices were unchanged. Intra- and inter-observer reproducibility was excellent (ICC 0.79-0.91). There were no correlations between HKA or MPTA angles and change in patellar height.

CONCLUSION

The present clinical series showed that patellar height was unchanged by isolated posteromedial OWHTO without change in tibial slope, using patient-specific cutting-guides, with whichever femoral or tibial reference index. The Schröter patellar femoral height index was highly reliable and is independent of proximal tibial changes in assessing patellar height, and can thus be recommended in the follow-up of OWHTO.

LEVEL OF EVIDENCE

III; retrospective cohort study.

Retro-Tubercle Biplanar Opening Wedge High Tibial Osteotomy Is Favorable for the Patellofemoral Joint But Not for the Osteotomized Tubercle Itself Compared With Supra-Tubercle Osteotomy

PURPOSE

To identify whether retro-tubercle opening-wedge high tibial osteotomy (RT-OWHTO) produces more favorable radiographic outcomes on patellofemoral joint alignment and clinical outcomes than supra-tubercle opening-wedge high tibial osteotomy (ST-OWHTO).

METHODS

From January 2017 to July 2018, patients who underwent biplanar OWHTO were allocated to 1 of 2 groups (ST-OWHTO and RT-OWHTO). Plain radiographs and computed tomography were used to analyze patellofemoral alignment and other radiologic parameters representing osteotomy configurations. Clinical outcomes were assessed using American Knee Society Score and Western Ontario and McMaster Universities Osteoarthritis Index.

RESULTS

In total, 50 knees that underwent ST-OWHTO and 44 knees that underwent RT-OWHTO were enrolled. Patellar height was significantly decreased only after ST-OWHTO (Caton-Deschamps ratio: P = .007; Blackburne-Peel ratio: P = .012). Patellar tilt angle was decreased in both groups (P = .009 and .004, respectively). Postoperative posterior tibial slope (PTS) (P = .013), PTS (Δ) (P < .001), retro-tuberosity gap distance (P = .001), and retro-tuberosity tip distance (P = .001) were significantly larger in RT-OWHTO. Retro-tuberosity tip distance was significantly correlated with retro-tuberosity gap distance (P = .002), thickness of second plane osteotomy fragment (P = .027), and anterior osteotomy ratio (P = .031) in ST-OWHTO. In RT-OWHTO, it was significantly correlated with PTS (△) (P < .001), retro-tuberosity gap distance (P < .001), and sagittal angle of bi-planar osteotomy (P = .005). There were 2 cases of tibial tuberosity fracture, 9 cases of delayed union on second plane osteotomy and 5 cases of tuberosity protrusion in RT-OWHTO.

CONCLUSIONS

Although the RT-OWHTO technique maintains patellofemoral joint alignment, no difference in clinical outcome was detected. The RT-OWHTO has increased risk of tuberosity fracture, delayed union, and prominent tibial tuberosity. The surgeon should consider these negative aspects of the technique and consider adjusting additional stabilization.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Effects of High Tibial Osteotomy Combined with Arthroscopy on Pain and Inflammation Markers in Patients with Medial Knee Osteoarthritis

OBJECTIVE

To investigate the effect of high tibial osteotomy (HTO) combined with arthroscopy on pain and serum inflammatory factors in patients with medial knee osteoarthritis.

METHODS

A total of 82 patients with medial knee osteoarthritis were admitted to our hospital. They were randomly divided into HTO-arthroscopy (HTO-A, treated with HTO combined with arthroscopy) group or HTO group (treated with HTO). The pain degree and serum inflammatory factors were primary outcomes. Moreover, the operation time, intraoperative blood loss, hospital stay, postoperative complications, hip-knee-ankle angle (HKA), medial proximal tibial angle (MPTA), posterior tibial slope angle, function of the knee joint [based on American knee society knee score (KSS) and hospital for special surgery knee score (HSS)] were also collected.

RESULTS

The hospital stay in HTO-A group was significantly lower than that in the HTO group (P < 0.05). On 1 month, 3 months and 6 months after operation, the KSS and HSS scores were higher and the pain degree was lower in HTO-A group than those in HTO group (P < 0.05). The operations of all patients were successful, and during the 6-month follow-up, there were no complications occurred in both groups, such as nerve or vascular injury, incision infection, fracture nonunion or delayed union, internal fixation failure and deep vein thrombosis.

CONCLUSION

HTO combined with arthroscopy could shorten the hospital stay, and effectively relieve pain degree and reduce serum inflammatory factors in patients with medial knee osteoarthritis, which is worthy of further clinical application.

Changes in patellar height and posterior tibial slope angle following uniplanar medial opening wedge high tibial osteotomy using a novel wedge-shaped spacer implanation concurrent with proximal partial fibulectomy

PURPOSE

The purpose of this study was to evaluate changes of patellar height and posterior tibial slope angle following uniplanar medial opening wedge high tibial osteotomy using a novel wedge-shaped spacer implanation concurrent with proximal partial fibulectomy.

METHODS

All patients who underwent uniplanar medial opening wedge high tibial osteotomy using a novel wedge-shaped spacer implanation concurrent with proximal partial fibulectomy between January 2017 and February 2019 were included and assessed retrospectively. Radiological assessment was made in terms of the changes in patellar height and posterior tibial slope angle between pre-operative and post-operative radiographs.

RESULTS

Thirty-five patients (9 males and 26 females) with a mean age of 57.3 years (range 50.8-64.2 years) were enrolled in this study protocol and demonstrated decreased posterior tibial slope angle post-operatively (9.7° ± 2.5° pre-operatively and 7.3° ± 1.8° post-operatively, P < 0.001). Patellar height was unchanged significantly post-operatively (Caton-Deschamps: 0.83 ± 0.12 pre-operatively and 0.82 ± 0.09 post-operatively, P > 0.05).

CONCLUSIONS

Uniplanar medial opening wedge high tibial osteotomy using a novel wedge-shaped spacer implanation concurrent with proximal partial fibulectomy can decrease posterior tibial slope and maintain the patellar height.

Changes in patellar height and patellofemoral alignment following double level osteotomy performed for osteoarthritic knees with severe varus deformity

Purpose

To evaluate the effect of double level osteotomy (DLO), a combination of a lateral closed distal femoral osteotomy (LCWDFO) and medial opening wedge high tibial osteotomy (MOWHTO), on patellar height and patellofemoral alignment as compared to those of isolated MOWHTO.

Methods

Twenty-six consecutive knees in 26 patients who underwent DLO (DLO group) constituted the study population. For comparative purpose, a control cohort (N: 26) matched for age, sex, and body mass index with the study group were selected from the patients who underwent isolated MOWHTO with an opening gap of more than 10 mm during the same period (MOWHTO group). Patellar height and patellofemoral alignment were assessed on radiographs preoperatively and at 2 years after surgery. For the patellar height, following parameters were measured on a lateral radiograph: Modified Insall-Salvati Index (mISI), modified Caton–Deschamps Index (mCDI), and modified Blackburne-Peel Index (mBPI). In the assessment of patellofemoral alignment, lateral patellar tilt (LPT) and lateral patellar shift (LPS) were measured on a skyline view. The measured values were statistically compared using the Student’s t-test.

Results

In the DLO group, the patellar height measured by mCDI and mPBPI significantly decreased after surgery. As regards the patellofemoral alignment, LPT significantly decreased with no significant postoperative change detected for LPS. When the amounts of postoperative changes in radiological indices were compared between the DLO and isolated MOWHTO groups, no significant differences were detected for all parameters.

Conclusion

DLO induced reduction in patellar height and decreased lateral patellar tilt. Those changes in patellar position and orientation were similarly observed in isolated MOWHTO knees. Although DLO is specifically indicated for knees with severe varus deformity, the two surgical options for correction of varus knee deformity exerted similar influences on patellofemoral biomechanics.

Five years of clinical and radiological results with biplanar tibial open-wedge osteotomy: feasible option to prevent patella infera?

INTRODUCTION

High tibial osteotomy (HTO) was a treatment option for relatively young active patients with isolated medial compartment arthritis of the knee. This report showed clinical and radiological results of a new HTO technique, that uses a particular open-wedge high tibial osteotomy by incorporating the tibial tubercle into osteotomy line (TT-OWHTO) to preserve patella height.

MATERIALS AND METHODS

Preoperative and postoperative function was recorded on the IKDC score, Kujala PF score, EQ-VAS and Tegner activity scale. Radiological patella height was measured with Insall-Salvati index. All this clinical and radiological recorded data on 45 active patients, with an average age of 40.2 years who underwent this procedure, allowed to do a retrospective analysis.

RESULTS

All the patients reported improvement in symptoms with an average preoperative IKDC score from preoperative value 49.7-92.3 at last follow-up. Kujala PF score improves from 67.2 preoperative value to 91.4. EQ-VAS self-assessment of quality of life reported a preoperative value of 41.2-92.2 at last follow-up. There was 2.5 point average improvement in Tegner activity scale. Patella height was not altered with median preoperative value of 0.84 ± 0.1 and final follow-up value of 0.81 ± 0.2 on Insall-Salvati index.

CONCLUSIONS

TT-OWHTO showed to be able to achieve good clinical and radiological results maintaining patella height unchanged and ensuring safety and reproducibility as much as the traditional technique.

Postoperative change in patellofemoral alignment following closing-wedge distal femoral osteotomy performed for valgus osteoarthritic knees

Purpose

To evaluate the postoperative change in patellar position after medial closed distal femoral osteotomy (DFO) performed for valgus osteoarthritic knees.

Methods

The study included 21 consecutive knees in 20 patients undergoing DFO. A minimum of 2-year follow-up data was obtained for all subjects with a mean follow-up period of 42 months (range 31–59 months). The patellar position was evaluated on plain radiographs preoperatively, 1-year postoperatively, and 2-year postoperatively. For patellar height, the modified Insall–Salvati Index (mISI), modified Caton–Deschamps Index (mCDI) and modified Blackburne–Peel Index (mBPI) were measured on the standing lateral radiographs. Patellofemoral alignment on the axial plane was assessed on skyline views with 30° flexion based on the measurements for lateral patellar tilt (LPT) and lateral patellar shift (LPS). Measured values at pre- and postoperative phases were statistically compared using a two-way analysis of variance.

Results

All indices including mISI, mCDI, mBPI, LPT and LPS showed no statistically significant postoperative changes.

Conclusion

Medial closed-wedge DFO performed for valgus osteoarthritic knees did not significantly influence patellofemoral alignment either on the sagittal or axial plane. Therefore, to highlight the clinical relevance of our findings, medial closed-wedge DFO for the valgus knee does not adversely affect the patellofemoral joint.

Level of evidence

Level IV, case series.

Tibial rotational alignment after opening-wedge and closing-wedge high tibial osteotomy

A lot of good outcomes have been reported after opening-wedge high tibial osteotomy (OWHTO) and closing-wedge high tibial osteotomy (CWHTO).The purpose of this study was to examine the rotational alignment after OWHTO and CWHTO performed by the same surgeon in one hospital.

The sample included 30 knees from 24 patients. In all cases, the same orthopaedic surgeon performed the osteotomy surgeries using the same method. The tibial external rotation angle (TERA) was measured using the CT images of proximal tibial plateau and distal tibial malleolus from the consecutive axial CT slices of tibia. In this study, two considerations were examined. The first was the change in rotation angle, which was defined by TERA noted before and after the operation. The second was the relationship between the correction angle of the osteotomy and the rotation angle change of the distal tibia. The first was evaluated using the paired-Student’s t-test, while the second was analyzed with Pearson’s correlation coefficient. In the OWHTO group, the mean TERA was 21.4± 7.0° preoperatively and 20.2 ± 8.0° postoperatively, but no significant difference was seen between pre- and post-operation measurements (p = 0.21). Significant TERA increasing (that is, external rotation of the distal tibia) was seen postoperatively in only three knees. In the CWHTO group, the mean TERA was 19.9 ± 10.5° preoperatively and 16.5 ± 9.5° postoperatively, and significant difference was seen between pre- and post-operative TERA (p < 0.05). No significant correlation was seen between the correction angle and the change of the rotation angle in either group (r = 0.40, r = 0.12) .

In the OWHTO group, both internal and external rotation of the distal tibia can occur after surgery. In the CWHTO group, the distal tibia rotated internally postoperatively. No significant correlation was seen between the correction angle and the change in the rotation angle in either group

Effect of increased posterior tibial slope on the anterior cruciate ligament status in medial open wedge high tibial osteotomy in an uninjured ACL population

PURPOSE

The purpose of this study was to clarify the relationship between posterior tibial slope angle (PTSA) and anterior cruciate ligament (ACL) status in medial open wedge high tibial osteotomy (OWHTO). Our hypothesis was that even though OWHTO may improve anteroposterior laxity of the knee, an increase in PTSA after OWHTO would be associated with ACL degeneration.

METHODS

Seventy-five patients treated with OWHTO were retrospectively analyzed. PTSA were evaluated radiographically pre- and postoperatively. The ACL was evaluated during the index arthroscopy at the time of OWHTO and a second-look arthroscopy during the plate removal, and scored from 1 (normal ACL) to 4 (complete tear). An anterior tibial translation (ATT) test was performed.

RESULTS

The mean time period from the index to second-look arthroscopy was 15.0±4.4months. PTSA significantly increased from 5.3±3.4° preoperatively to 7.5±4.0° postoperatively (p<0.001). The average ACL score significantly increased from 1.9±0.5 at the index arthroscopy to 2.2±0.5 at the second-look arthroscopy (p=0.0025). The average ATT on the operated side significantly decreased from 7.1±2.6mm preoperatively to 5.3±2.3mm at the second-look arthroscopy (p<0.0001). There was a significant positive correlation between the increase in PTSA and the change of ACL grade [correlation coefficient (r)=0.221, p<0.05].

CONCLUSION

Even though OWHTO reduces anteroposterior knee laxity, an increase in PTSA is associated with ACL degeneration. It is important for the surgeon to avoid an increase in PTSA during the intervention to prevent ACL degeneration after OWHTO.

LEVEL OF EVIDENCE

IV, therapeutic retrospective case series.

Risk of patella baja after opening-wedge high tibial osteotomy

PURPOSE

Medial opening-wedge high tibial osteotomy (OWHTO) induces a lower patellar position, and the subsequent degree of patellar movement may not be predicted preoperatively. The purpose of this study was to clarify the relationship between preoperative and postoperative patellar height based on the correction angle of OWHTO and to create a formula to predict the appearance of patella baja following OWHTO.

MATERIALS AND METHODS

Seventy-five knees with varus knee osteoarthritis treated with OWHTO were included in this study. The Caton-Deschamps index was used to evaluate patellar height preoperatively and postoperatively, and the cut-off value for preoperative parameters was determined by a receiver operating characteristic curve to determine the risk ratio for postoperative patella baja.

RESULTS

The Caton-Deschamps index significantly decreased from 0.93 to 0.77 after OWHTO ( p < 0.01). The OWHTO correction angle negatively correlated with the delta Caton-Deschamps index ( r = -0.44, p < 0.01), and a 1.7% decrease in the Caton-Deschamps index was shown with a 1° correction angle. Receiver operating characteristic curve analysis revealed that a Caton-Deschamps index of 0.8 was the cutoff for OWHTO; knees with a preoperative Caton-Deschamps index of < 0.8 tended to develop patella baja after OWHTO, with a risk ratio of 9.5 (95% confidence interval [4.3-20.7]).

CONCLUSIONS

OWHTO can induce patella baja, and a 1.7% decrease in the Caton-Deschamps index was shown with a 1°-correction angle. A preoperative Caton-Deschamps index < 0.8 should be considered a risk factor for postoperative patella baja.

LEVEL OF EVIDENCE

Retrospective study, Level IV.

Radiographic changes and clinical outcomes after open and closed wedge high tibial osteotomy: a systematic review and meta-analysis

BACKGROUND

The purpose of this meta-analysis is to examine changes in radiological variables and clinical outcomes between open and closed wedge high tibial osteotomy (OWHTO and CWHTO, respectively), which have ongoing controversial issues in numerous quantitative clinical studies.

METHODS

PubMed, Embase, and the Cochrane Library were systematically searched for suitable controlled trials between Jan 1, 1999, and Feb 2, 2018. The inclusion criteria included studies written in English, studies with a level of evidence of I-IV, and studies presenting comparisons between OWHTO and CWHTO. The main clinical and radiographic results were extracted and pooled using Stata 12.0.

RESULTS

After searching for and screening trials, 28 trials involving 2840 knees were eligible for the meta-analysis. After OWHTO or CWHTO, clinical scores, including the American Knee Society Score, Hospital for Special Surgery Knee Score, Lysholm score, and Visual Analog Scale pain score, improved (p < 0.05), but the range of motion was unchanged (p > 0.05). The anatomical femorotibial angle (SMD 0.04, 95% CI - 0.66 to 0.74) and hip-knee-ankle angle (SMD 0.11, 95% CI - 0.11 to 0.33) data suggested that the OWHTO and CWHTO groups were similar in function of correction. Posterior tibial slope increased (SMD - 0.71, 95% CI - 1.04 to - 0.37) after OWHTO but decreased (SMD 0.72, 95% CI 0.35 to 1.08) after CWHTO. OWHTO decreased patellar height (p < 0.05), while patellar height did not change significantly after CWHTO (p > 0.05).

CONCLUSION

This meta-analysis indicates that compared with CWHTO, OWHTO increases the posterior slope, decreases the patellar height, and provides a similar accuracy of correction; however, CWHTO leads to a decreased posterior slope and an unchanged patellar height. Therefore, programs should be personalized and customized for the specific situation of each patient.

Hybrid high tibial osteotomy is superior to medial opening high tibial osteotomy for the treatment of varus knee with patellofemoral osteoarthritis

PURPOSE

To evaluate patellofemoral congruity after opening wedge high tibial osteotomy (OWHTO) and hybrid HTO.

METHODS

Twenty-four knees with hybrid HTO and 24 with OWHTO were evaluated in this study. The Caton-Deschamps and modified Miura-Kawamura indices were used to evaluate pre- and post-operative patellar heights for both types of surgery. Tibial tuberosity-trochlear groove (TT-TG) distance, patellar tilt, and medial and lateral joint space at the patellofemoral joint were compared. Anterior knee pain was assessed using the Kujala anterior knee pain scale.

RESULTS

There was no significant difference between the correction angles of the hybrid HTO and OWHTO. Pre- and post-operative values for the Caton-Deschamps and modified Miura-Kawamura indices in patients who underwent hybrid HTO changed from 0.90 to 0.94 and from 0.95 to 1.03, respectively, with no significant differences noted. Following OWHTO, these values decreased significantly from 0.91 to 0.73 and from 1.06 to 0.84, respectively (p < 0.01). The post-operative patellar height after OWHTO was significantly lower than that after hybrid HTO (p < 0.01). After hybrid HTO, the TT-TG distance decreased significantly from 11.4 to 7.4 (p < 0.01), but it did not change significantly after OWHTO. Although pre- and post-operative patellar tilt were not altered significantly in either group, the medial joint space of the patellofemoral joint was significantly increased post-operatively following hybrid HTO (p = 0.035). The pre-operative Kujala scores were significantly lower in the hybrid HTO group, but post-operative scores improved in both groups.

CONCLUSIONS

Hybrid HTO provides a better post-operative patellofemoral joint than does OWHTO with regard to patellar position and reduction of the TT-TG distance, as well as improved clinical outcomes. Hybrid HTO, rather than OWHTO, is the preferred technique for the treatment of varus knees combined with patellofemoral osteoarthritis.

LEVEL OF EVIDENCE

Retrospective comparative study, Level III.

Biplane opening wedge high tibial osteotomy with a distal tuberosity osteotomy, radiological and clinical analysis with minimum follow-up of 2 years

Background

High tibial osteotomy is an established and helpful treatment for unicompatimental osteoarthritis associated with varus deformity. However, asupratubercle high tibial osteotomy leads to a decrease in patellar height making the technique not suitable in case of concomitant patella baja. Moreover, this kind of osteotomy can change in situ forces at patellofemoral joint and the lateral patellar tilt. With the aim to widen the indication of high tibial osteotomy was proposed a biplane opening wedge high tibial osteotomy with a distal tuberosity osteotomy (B-OWHTO). This technique provide that the tibial tuberosity remains joined to the tibial metaphysis so as not to theoretically alter the patellar height. However, some Authors claim that BOWHTO could lead to an increase in tibial slope. The purpose of the present study was to assess the tibial slope, patella-femoral changes and axial correction as well as functional outcomes following a B-OWHTO.

Methods

Patients operated on with a B-OWHTO and a minimum 24 months of follow-up were included. The mechanical alignment of the lower limb, patellar height, lateral patellar tilt and posterior tibial slope were calculated preoperatively, immediately after surgery and at the 24-month follow-up. The clinical results were evaluated using the Lysholm, Kujala and Hospital for Special Surgery knee scores. The possible postoperative development of patellofemoral pain or radiologic patellofemoral alteration was also evaluated.

Results

Twenty-three patients were included with a mean follow-up of 33 months (range 27-41). The mechanical alignment of the lower limb shifted from a mean 9.3º ± 2.5 varus preoperatively to a mean 0.2º ± 2.2 valgus postoperatively. No changes in patellar height, lateral patellar tilt or in the posterior tibial slope were observed. The mean Lysholm and HSS scores improved from 68.3 ± 9.1 and 64.2 ± 5.2 preoperatively to 93.2 ± 2.1 and 94.1 ± 3.6 at final follow-up (p < 0.01). The mean Kujala score improved from 67.3 ± 9.8 to 86.4 ± 7.6 at final follow up (p < 0.01). No patients developed both radiological or clinical symptoms at patellofemoral joint.

Conclusions

Open wedge high tibial osteotomy with a dihedral L-cut distal and posterior to the tibial tubercle accurately corrected axial malalignment without any change at patella-femoral joint or any modification to the posterior tibial slope while providing improved knee function at short-term follow-up. The radiographic as well as the clinical results support the use of this technique to treat medial compartment knee osteoarthritis and varus malalignment in young and middle-aged patients with a normal-to-low patellar height.

Level of evidence

Case series with no comparison group, Level IV.

Open-Wedge Valgus High Tibial Osteotomy Technique With Inverted L-Shaped Configuration

High tibial osteotomy (HTO) is a useful alternative in the treatment of symptomatic varus malalignment. However, among its drawbacks is the tendency to decrease patellar height and increase the posterior tibial slope. The increased tibial slope increases anterior cruciate ligament tension and may compromise its function. On the other hand, patella baja often causes anterior knee pain and, over time, may favor degeneration of the patellofemoral joint. The aim of this study is to describe a technical modification of the standard open-wedge HTO. It consists of a double inverted L-shaped cut, which includes the anterior tibial tuberosity in the proximal fragment, to avoid any alteration of patellar height and control the eventual increase of the posterior tibial slope.

No change in patellar height following open wedge high tibial osteotomy using a novel femur-referenced measurement method

BACKGROUND

Open wedge high tibial osteotomy (HTO) can influence the tibial slope and thereby the landmarks of currently used patellar height indices. The purpose of this retrospective study was to compare and validate a new femur-referenced patella height measurement method to currently used patellar height indices in a cohort of HTO patients.

METHODS

Patellar height (Caton-Deschamps, Blackburne-Peel and Insall-Salvati Indices and our newly developed Femoral Patellar Height Index) as well as tibial slope were analysed. Full-weight-bearing long-leg anteroposterior radiographs as well as anteroposterior and lateral radiographs of the knee in 0° of extension were used. Radiographs were performed preoperatively, and at six weeks, three, six, 12 and 18months postoperatively. Measurements were recorded twice by two observers. The second observation was performed after a delay of three months.

RESULTS

A total of 99 patients with a mean age of 46.2±8years were included. A statistically significant pre- to postoperative increase in tibial slope was found in all methods. Patellar height decreased according to Caton-Deschamps and Blackburne-Peel Indices. The Insall-Salvati Index as well as the novel Femoral Patellar Height Index remained unchanged. Intra-rater (interclass correlation coefficient (ICC) 0.914-0.998) and inter-rater (ICC 0.955-0.989) reliability were highest in the new index.

CONCLUSION

Detected changes of patellar height following open wedge HTO depend on the method used. Tibial slope increases following surgery. Our new index with a femoral reference for measuring patellar height was validated and good to excellent intra- and inter-rater reliability were demonstrated. Following HTO, the Femoral Patellar Height Index can be recommended as a standardized method to measure patellar height.

Radiological outcomes in a randomized trial comparing opening wedge and closing wedge techniques of high tibial osteotomy

PURPOSE

The aim of the present study was to examine changes in radiological variables in a prospective randomized study comparing opening wedge (OW) and closing wedge (CW) techniques of high tibial osteotomy (HTO). Our hypothesis was that there would be no differences in joint line angles or correction accuracy between the two groups, that patellar height would increase after CW HTO and decrease after OW HTO, and that leg length and posterior tibial slope would decrease after CW HTO and increase after OW HTO.

METHODS

Radiological data were collected from 70 patients participating in an ongoing prospective randomized clinical trial comparing OW and CW HTOs. Digital standing hip-knee-ankle (HKA) radiographs as well as lateral radiographs in 30° of flexion were obtained preoperatively and at 6 months for each patient. Joint line angles, HKA angle, leg length, Insall-Salvati index, Miura-Kawamura index and posterior tibial slope were measured using medical planning software. The complete preoperative radiological examinations of the first 50 patients were used in a study of intra- and inter-rater reliability of the measurements.

RESULTS

The mean posterior slope was reduced by 2.5° in CW HTO, whereas it remained unchanged in OW HTO (p < 0.001). Mean leg length decreased 5.7 mm in CW HTO and increased 3.1 mm in OW HTO (p < 0.001). Changes in joint line angles, patellar height indexes and the correction accuracy showed no significant differences comparing the two techniques. Frontal plane reliability measurement intra- and inter-rater intraclass correlation coefficient (ICC) varied from 0.81 to 0.99. Sagittal plane intra- and inter-rater ICC varied from 0.60 to 0.87. Posterior tibial slope intra- and inter-rater ICC showed the lowest values (0.70 and 0.60, respectively) corresponding to a smallest real difference of 4.5° and 5.5°, respectively.

CONCLUSIONS

Posterior tibial slope and leg length changes were significantly different in CW compared to OW HTOs. We recommend that possible alterations in tibial slope and leg length are considered when the technique of HTO is to be chosen. Landmark-based medical planning software shows good reliability and can be used in preoperative planning and postoperative evaluations of HTOs.

LEVEL OF EVIDENCE

I.

Comparison of clinical and radiological outcomes between opening-wedge and closing-wedge high tibial osteotomy: A comprehensive meta-analysis

High tibial osteotomy (HTO) has been widely used for clinical treatment of osteoarthritis of the medial compartment of the knee, and both opening-wedge and closing-wedge HTO are the most commonly used methods. However, it remains unclear which technique has better clinical and radiological outcomes in practice. To systematically evaluate this issue, we conducted a comprehensive meta-analysis by pooling all available data for the opening-wedge HTO and closing-wedge HTO techniques from the electronic databases including PubMed, Embase, Wed of Science and Cochrane Library. A total of 22 studies encompassing 2582 cases were finally enrolled in the meta-analysis. There was no significant difference regarding surgery time, duration of hospitalization, knee pain VAS, Lysholm score and HSS knee score (clinical outcomes) between the opening-wedge and closing-wedge HTO groups (P > 0.05). However, the opening-wedge HTO group showed wider range of motion than the closing-wedge HTO group (P = 0.003). Moreover, as for Hip-Knee-Ankle angle and mean angle of correction, no significant difference was observed between the opening-wedge and closing-wedge HTO groups (P > 0.05), while the opening-wedge HTO group showed greater posterior tibial slope angle (P < 0.001) and lesser patellar height than the closing-wedge HTO group (P < 0.001). On light of the above analysis, we believe that individualized surgical approach should be introduced based on the clinical characteristics of each patient.

Changes in Patellar Height After Opening Wedge and Closing Wedge High Tibial Osteotomy: A Meta-analysis

PURPOSE

To test that patellar height decreases (patellar baja) after opening wedge high tibial osteotomy (HTO) and increases (patellar alta) after closing wedge HTO. In addition, this meta-analysis evaluated whether the method of measuring patellar height affected the change in patellar height after opening and closing HTO.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, all studies comparing pre- and postoperative patellar height using various indices, including the Insall-Salvati index (ISI), Blackburne-Peel index, and Caton Deschamps index, in patients who underwent opening or closing wedge HTO were included. The main outcome of this meta-analysis, mean change in patellar height from before to after surgery, was analyzed with a random effects model. Publication bias was evaluated using funnel plots and Egger's test.

RESULTS

Twenty-three studies were included in the meta-analysis. Pooled data, including subgroups of the 3 measurement methods, showed that patellar height decreased 7% after opening wedge HTO (95% confidence interval [CI]: 0.05 to 0.10; P < .001), except when patellar height was assessed by ISI (95% CI: -0.02 to 0.06; P = .34), but that there was no change in patellar height after closing HTO (95% CI: -0.01 to 0.04; P = .29).

CONCLUSIONS

The patellar height decreased after opening wedge HTO, except when assessed by ISI. In contrast, patellar height was unchanged after closing wedge HTO, regardless of the measurement method.

LEVEL OF EVIDENCE

Level II, meta-analysis of Level I and II studies.

The biplanar open wedge high tibial osteotomy preserving the tibial tubercle

BACKGROUND

High tibial osteotomy (HTO) is a treatment option for relatively young patients with isolated medial compartment arthritis of the knee. Medial open wedge osteotomies allow easier control of correction, but can lead to patella infera as a result of distalization of the tibial tubercle. This retrospective study reports results of a biplanar tibial tubercle preserving HTO, designed to preserve patellar height.

METHODS

The study is a retrospective analysis of 12 consecutive patients (11 men, 1 woman) average age 39.6 years who underwent the procedure between 2009 and 2012. A biplanar open wedge tibial osteotomy was performed and stabilised with a medial locking plate. Patients were allowed full weight bearing at 6 weeks. Preoperative and postoperative function was recorded on the Oxford knee score, Lysholm score and Tegner activity scale. Minimum follow up was 26 months.

RESULTS

All patients had healing of the osteotomy with no delayed union. Eleven patients reported improvement in symptoms with an average preoperative Oxford score of 26 and postoperative score of 39 out of 48. The Lysholm score improved from 58 to 72 out of 100. There was one point improvement in Tegner activity scale. There was no statistical difference in patellar height before and one year after surgery. The correction in varus averaged 8.3°.

CONCLUSION

The biplanar High tibial Osteotomy allows preservation of patellar height, while achieving desired varus correction.

Opening-wedge high tibial osteotomy with a secure bone allograft (Osteopure™) and locked plate fixation: Retrospective clinical and radiological evaluation of 69 knees after 7.5years follow-up

BACKGROUND

Medial opening-wedge high tibial osteotomy (OWHTO) provides reliable and long-lasting benefits, despite the wide range of wedge-filling and internal-fixation techniques used. The purpose of this work was to assess the clinical and radiological outcomes in a case-series of OWHTO performed using a secure bone allograft and locked plate fixation.

HYPOTHESIS

The clinical and radiological outcomes of OWHTO with a high-safety bone allograft and locked plate fixation are similar to those reported in previous case-series studies.

MATERIALS AND METHODS

A single-centre retrospective design was used to study 69 knees in 64 patients with a mean age of 51.8years (31-53years) and a preoperative hip-knee-ankle (HKA) angle of 173° (165°-180°). The wedge was filled with secure Osteopure™ bone allograft and fixation was achieved using an Integra Surfix(®) locked plate. Mean follow-up was 7.5years (5-9.3years). Clinical and functional outcomes were assessed by determining the IKS and KOOS-PS scores and recording complications related or unrelated to the allograft. The main criterion for assessing OWHTO survival was the time to revision surgery for symptom recurrence. Radiological assessment criteria were the HKA angle, tibial slope, patellar height, and osteoarthritis grade. GESTO criteria were used to evaluate the behaviour of the allograft.

RESULTS

Of the 69 knees, 64 (92.8%) were re-evaluated. The survival rate after 9.3years was 95%±2.7% (3 failures managed with arthroplasty). The functional IKS score improved significantly, by 20 points (P<0.001). Mean increases of 7.8° for the HKA angle and 3.5° for tibial slope were recorded. Bone healing without radiological abnormalities was consistently achieved within 6months. There were no complications related to the allograft (infections, allergies; local or systemic toxicity).

DISCUSSION

The clinical, radiological, and safety outcomes documented in our study were similar to those reported in earlier work.

LEVEL OF EVIDENCE

IV, retrospective case-series study.

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

PURPOSE

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.

METHODS

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.

RESULTS

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 %.

CONCLUSIONS

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.

LEVEL OF EVIDENCE

Retrospective case series, Level IV.

Combined tibial tubercle osteotomy with medial opening wedge high tibial osteotomy minimizes changes in patellar height: a prospective cohort study with historical controls

BACKGROUND

Medial opening wedge high tibial osteotomy (HTO) for the treatment of varus gonarthrosis can be associated with inadvertent decreases in patellar height.

HYPOTHESIS

Decreases in patellar height observed after medial opening wedge HTO can be minimized with the addition of a tibial tubercle osteotomy (TTO).

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Twenty-nine patients undergoing medial opening wedge HTO with a concurrent TTO were matched with 29 controls who previously underwent medial opening wedge HTO without a TTO. Both groups had substantial varus malalignment (mean mechanical axis angle, -10° ± 3°) requiring large corrections. Measurements of patellar height and posterior tibial slope were calculated from standing lateral radiographs and compared preoperatively and 6 months postoperatively. Patellar height measures included the Blackburne-Peel index, Caton-Deschamps index, Miura-Kawamura index, Insall-Salvati ratio, and modified Insall-Salvati ratio.

RESULTS

The changes in the Blackburne-Peel, Caton-Deschamps, and Miura-Kawamura indices were significantly less in the HTO/TTO group versus the HTO group. There were 3 of 29 (10%) new cases that met the radiographic criteria for patella infera in the HTO/TTO group versus 11 of 29 (38%) new cases of patella infera found postoperatively in the HTO group, suggesting an absolute risk reduction of 28% with TTO. The changes in the Blackburne-Peel and Caton-Deschamps indices were correlated to a larger preoperative varus deformity in the coronal plane (r = 0.52 and r = 0.41, respectively).

CONCLUSION

The addition of a TTO when performing a medial opening wedge HTO minimizes the decreases in patellar height associated with the procedure.