Inverted V-shaped high tibial osteotomy compared with closing-wedge high tibial osteotomy for osteoarthritis of the knee

Bilateral Inverted V-shaped High Tibial Osteotomy: A Case Report

The article describes the case of a young patient with bilateral genu varum deformity, limiting her mobility. The therapeutic decision was a staged reverse V-shaped tibial osteotomy on both knees at a six-month interval. The surgery faced infectious complications on the left side, requiring additional treatment. Despite this, the patient achieved successful correction, with wound healing and bone consolidation. Preoperative planning was crucial, determining specific correction angles for each knee. The reverse V-shaped osteotomy demonstrated satisfactory functional outcomes compared to other techniques. The conclusion emphasizes the effectiveness of reverse V-shaped high tibial osteotomy (HTO) in addressing varus tibial deformities, providing an alternative before considering total knee arthroplasty. Multicenter studies and long-term evaluations are recommended to refine this surgical procedure.

Effect of Patient Age on Clinical and Radiological Outcomes After Medial Open-Wedge High Tibial Osteotomy: A Comparative Study With 344 Knees

Background

There exists some controversy regarding whether patient age is a predictive factor for outcomes after high tibial osteotomy (HTO).

Purpose/Hypothesis

The purpose of this study was to evaluate whether patient age affects clinical and radiological outcomes after medial open-wedge HTO (OWHTO) in a large population with a wider age range than previous studies. It was hypothesized that there would be no differences in outcomes when compared across age-groups.

Study Design

Cohort study; Level of evidence, 3.

Methods

A retrospective comparative study was conducted using 344 patients (303 knees) who underwent OWHTO from 2009 to 2018. These patients were divided into 3 groups based on age at the time of surgery: ≥55 years (group Y: 76 knees in 57 patients), 56 to 64 years (group M: 129 knees in 120 patients), and ≤65 years (group O: 139 knees in 126 patients). Clinical and radiological evaluations were performed immediately before surgery and at the final follow-up period, at a mean of 5.1 years (range, 3-11 years). Comparisons among the 3 groups were conducted with 1-way analysis of variance for continuous variables. When a significant result was obtained, a post hoc test with Bonferroni correction was conducted for multiple comparisons.

Results

In clinical evaluations, there were no significant differences among the 3 groups either preoperatively or postoperatively concerning the Japanese Orthopaedic Association score, the Lysholm score, or the Knee injury and Osteoarthritis Outcome Score (KOOS), with the exception of the preoperative KOOS Symptoms subscale, which was significantly higher in group Y versus group O (48.9 ± 18.7 vs 58.7 ± 15.4, respectively; P = .011). The Tegner activity score was significantly different among the groups, both preoperatively and postoperatively (P < .001 for both). There was no significant difference in the occurrence of complications or the survival rate at final follow-up among the 3 groups.

Conclusion

The study findings suggest that patient age does not affect clinical and radiological outcomes after OWHTO.

Clinical relevance of joint line obliquity after high tibial osteotomy for medial knee osteoarthritis remains controversial: a systematic review

PURPOSE

To systematically review the literature on the association between knee joint line obliquity (KJLO) and clinical outcome after high tibial osteotomy (HTO) for medial knee osteoarthritis and summarize the KJLO cut-off value used when studying this association.

METHODS

A systematic search was conducted in three databases (PubMed, Embase, and Web of Science) on September 2022, updated on February 2023. Eligible studies describing postoperative KJLO in relation to clinical outcome after HTO for medial knee osteoarthritis were included. Nonpatient studies and conference abstracts without full-text were excluded. Two independent reviewers assessed title, abstract and full-text based on the inclusion and exclusion criteria. The modified Downs and Black checklist was used to assess the methodological quality of each included study.

RESULTS

Of the seventeen studies included, three had good methodological quality, thirteen fair quality, and one had poor quality. Conflicting findings were shown on the associations between postoperative KJLO and patient-reported outcome, medial knee cartilage regeneration, and 10-year surgical survival in sixteen studies. Three good-quality studies found no significant differences in lateral knee cartilage degeneration between postoperative medial proximal tibial angle > 95° and < 95°. Joint line orientation angles by the tibial plateau of 4° and 6°, joint line orientation angle by the middle knee joint space of 5°, medial proximal tibial angles of 95° and 98°, and Mikulicz joint line angle of 94° were KJLO cut-off values used in the included studies.

CONCLUSION

Based on current evidence, the actual association between postoperative KJLO and clinical consequences after HTO for medial knee osteoarthritis cannot be ascertained. The clinical relevance of KJLO after HTO remains controversial.

LEVEL OF EVIDENCE

IV.

Efficacy of intravenous tranexamic acid administration in medial opening-wedge distal tibial tuberosity osteotomy (MOWDTO) for varus knee osteoarthritis: a randomized control trial

BACKGROUND

This randomized controlled study was undertaken to investigate the efficacy of intravenous tranexamic acid (TXA) administration in reducing perioperative blood loss in patients undergoing medial opening-wedge distal tibial tuberosity osteotomy (MOWDTO). It was hypothesized that TXA would reduce perioperative blood loss in MOWDTO.

METHODS

A total of 61 knees in 59 patients who underwent MOWDTO during the study period were randomly assigned to either of the groups with intravenous TXA administration (TXA group) or without TXA administration (control group). In the TXA group, patients received 1000 mg of TXA intravenously before skin incision and 6 h after the first dose. The primary outcomes was the volume of perioperative total blood loss which calculated using the blood volume and hemoglobin (Hb) drop. The Hb drop was calculated as the difference between preoperative Hb and postoperative Hb at days 1, 3, and 7.

RESULTS

The perioperative total blood loss was significantly lower in the TXA group (543 ± 219 ml vs. 880 ± 268 ml, P < 0.001). The Hb drop was significantly lower at postoperative days 1, 3 and 7 in the TXA group than in the control group (day 1: 1.28 ± 0.68 g/dl vs. 1.91 ± 0.69 g/dl, P = 0.001; day 3: 1.54 ± 0.66 g/dl vs. 2.69 ± 1.00 g/dl, P < 0.001; day 7: 1.74 ± 0.66 g/dl vs. 2.83 ± 0.91 g/dl, P < 0.001).

CONCLUSION

Intravenous TXA administration in MOWDTO could reduce the perioperative blood loss. Trial registration The study was approved by the institutional review board. (Registered on 26/02/2019 Registration Number 3136). Level of Evidence Level I, randomized controlled trial.

Influence of lateral hinge fractures on biplanar medial closing-wedge distal femoral osteotomy for valgus knee: a new classification of lateral hinge fracture

BACKGROUND

The purpose of this study was to examine the influence of lateral hinge fractures in medial closing-wedge distal femoral osteotomy (MCWDFO) on bone union.

METHODS

Twenty-one patients were followed-up for more than 1 year after MCWDFO. The incidence and type of hinge fracture, as well as the course of bone healing, were investigated. Slow healing was defined as bone union was not obtained until 3 months after surgery.

RESULTS

Hinge fractures were observed in 12 cases (57%). There were three types of hinge fractures. Type 1: the lateral cortex was completely cut through (4 cases), type 2: the osteotomy line was too proximal (6 cases), and type 3: the hinge point was significantly medial (2 cases). There was a significant difference in the mean correction angles between hinge fracture and no-fracture cases, with the mean angles being 13.8 ± 4.0° and 9.6 ± 3.1°, respectively. Sixty-seven percent (8/12) of cases with hinge fractures developed slow healing. Among the hinge fracture cases, when there was no displacement of the hinge fracture and good contact with the anterior flange, 40% (2/5) of cases developed slow healing. If there was displacement of the hinge or no contact of the anterior flange, 86% (6/7) of cases developed slow healing. In contrast, only 11% (1/9) of subjects who did not have a hinge fracture, developed slow healing. In 67% (6/9) of cases with slow healing, a correction loss of 2° or greater (average: 4.3 degrees valgus) was observed. There were no cases of non-union. Clinical outcomes at 1 year showed no significant difference between the groups with and without hinge fractures.

CONCLUSIONS

There is a very high risk of hinge fracture in patients undergoing MCWDFO. Hinge fractures often lead to slow healing and a loss of correction. We recommend the endpoint of the distal lateral cortex of the femur as the ideal hinge point for the prevention of hinge fractures. Bone union is obtained slowly in even all hinge fracture cases without revision surgery. Consequently, surgical results are not affected by the occurrence of hinge fracture at 1 year.

Early Changes in Postural Balance Following Inverted V-Shaped High Tibial Osteotomy in Patients With Knee Osteoarthritis

Patients with knee osteoarthritis and varus knee deformity have impaired postural balance, resulting in decreased walking performance and an increased risk of falls. This study aimed to investigate the early changes in the postural balance following inverted V-shaped high tibial osteotomy (HTO). Fifteen patients with medial knee osteoarthritis were recruited. Postural balance was assessed using the center-of-pressure (COP) data during single-leg standing before and 6 weeks after inverted V-shaped HTO. The maximum range, mean velocity, and area of COP movements in the anteroposterior and mediolateral directions were analyzed. Preoperative and postoperative visual analog scale for knee pain was assessed. The maximum range of COP in the mediolateral direction decreased (P = .017), whereas the mean velocity of COP in the anteroposterior direction increased 6 weeks postoperatively (P = .011). The visual analog scale score for knee pain significantly improved at 6 weeks postoperatively (P = .006). Valgus correction with inverted V-shaped HTO resulted in improved postural balance in the mediolateral direction and good short-term clinical outcomes early following surgery. Early rehabilitation after inverted V-shaped HTO should focus on postural balance in the anteroposterior direction.

High Rate of Radiographic Union at the Fibular Osteotomy Site With No Complications After an Acute Oblique Osteotomy and Ligation Procedure to Shorten the Fibula in High Tibial Osteotomy

Background:

A fibular shortening osteotomy is needed to perform lateral closing-wedge high tibial osteotomy (LCW-HTO). To achieve this shortening, we have recently developed an acute oblique osteotomy and ligation (AO/L) procedure for the center of the fibular shaft, based on the AO procedure.

Purpose:

To compare the 2-year follow-up outcomes between the AO/L procedure and the AO procedure.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

A prospective comparative cohort study was conducted involving 83 patients (83 knees) who underwent shortening osteotomy of the fibula in LCW-HTO between April 2017 and March 2019. The first consecutive 41 knees (AO group) underwent fibular osteotomy with the AO procedure. The remaining 42 knees (AO/L group) underwent fibular osteotomy with the AO/L procedure. All of the patients were evaluated for at least 2 years postoperatively via clinical and radiological assessments. To determine the time needed for complete union at the osteotomy site, we evaluated the radiographs using a radiographic union score for tibial fractures, which was modified for fibular osteotomy. Comparison of outcomes between the 2 groups was performed using the Student t test for continuous variables and the Mann-Whitney U test or Fisher exact test for discrete variables.

Results:

Around the fibular osteotomy site, no perioperative complications were found in either group. The radiographic union score was significantly higher in the AO/L group than in the AO group (P < .0001 at 2, 3, and 6 months; P = .0290 at 12 and 24 months). The union rate at the fibular osteotomy site was significantly higher in the AO/L group (97.6%) than in the AO group (82.9%) at 12 months (P = .0290).

Conclusion:

The AO/L procedure significantly accelerated the formation of bridging callus at the fibular osteotomy site and provided a significantly higher union rate compared with the AO procedure. Both AO/L and AO procedures were free from perioperative complications. These results suggest that the AO/L procedure is clinically useful as an osteotomy procedure to shorten the fibula in LCW-HTO.

Effect of the Inverted V-Shaped Osteotomy on Patellofemoral Joint and Tibial Morphometry as Compared With the Medial Opening Wedge High Tibial Osteotomy

BACKGROUND

Recent studies have reported that medial opening wedge (OW) high tibial osteotomy (HTO) induces patella baja, resulting in degenerative changes in the patellofemoral joint. We have developed an inverted V-shaped (iV) HTO, which is classified as a neutral wedge osteotomy.

HYPOTHESES

The study hypotheses were as follows: (1) patellar height, posterior tibial slope, and tibial length will not change between pre- and postoperative evaluations after iV-HTO; (2) the lateral shift ratio of the patella and the distance between the tibial tubercle and the trochlear groove may be significantly decreased after iV-HTO.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 191 patients (220 knees) who underwent HTO for medial osteoarthritis were enrolled retrospectively in this study: 107 knees underwent OW-HTO and 113 knees underwent iV-HTO. Clinical and radiological evaluations were performed before and at least 3 years after surgery.

RESULTS

Postoperatively, the mean Caton-Deschamps ratio was significantly decreased (P < .0001) from 0.95 to 0.79 in the OW group, while there were no significant changes in the iV group. The mean posterior tibial slope was significantly increased (P < .0001) from 8.5° to 10.5° in the OW group, while there were no significant differences in the iV group. Although the entire leg length was significantly increased (P < .0003) in both groups after HTO, there were no significant differences in tibial length between the pre- and postoperative periods in the iV group. Regarding the congruity of the patellofemoral joint, the mean lateral shift ratio did not significantly change in the OW group, whereas it was significantly decreased (P = .0012) from 11.5% to 8.8% in the iV group. The mean tibial tubercle-trochlear groove distance was significantly decreased (P < .0001) from 12.8 to 9.7 mm in the iV group, while it was significantly increased in the OW group (P < .0001). Concerning the clinical outcome, the Japanese Orthopaedic Association (JOA) and Lysholm knee scores at final follow-up (OW vs iV: JOA, 91.2 vs 90.1; Lysholm, 92.5 vs 89.0) were significantly increased (P < .0001) as compared with the preoperative values (OW vs iV: JOA, 68.3 vs 66.8; Lysholm, 67.9 vs 61.0).

CONCLUSION

Patellar height, posterior tibial slope, and tibial length did not change after the iV-HTO, while they were significantly changed after the OW-HTO. Although the preoperative degrees of varus knee and patellofemoral osteoarthritis were more severe in the iV group than the OW group, the iV-HTO led to altered patellofemoral joint congruity.

Inverted V-Shaped High Tibial Osteotomy Decreases the Posterior Tibial Slope More but Shortens the Tibia Less Than Closed-Wedge High Tibial Osteotomy

PURPOSE

To assess the postoperative anatomical changes in the lower extremity after inverted V-shaped high tibial osteotomy (IVHTO) using 3-dimensional (3D) computed tomography (CT) bone models and compare those changes after closed-wedge high tibial osteotomy (CWHTO).

METHODS

Preoperative and 3-week postoperative CT scanning of the lower extremity were obtained from patients who underwent IVHTO and CWHTO between October 2019 and March 2021. 3D CT bone models were reconstructed using ZedKnee software. The postoperative changes (Δ) in (1) posterior tibial slope (PTS), (2) knee rotation angle (KRA), (3) tibial torsional angle (TTA), (4) patella tilt (PT), (5) Insall-Salvati ratio (ISR), and (6) tibial length (TL) were compared between IVHTO and CWHTO.

RESULTS

Thirty-seven knees (18 IVHTO and 19 CWHTO) in 34 patients were retrospectively enrolled in this study. ΔPTS at the medial and lateral tibial plateau in the IVHTO group (-6.5° and -5.0°) was larger compared with that in the CWHTO group (-3.3° and -2.0°; P = .024 and P = .002, respectively). No significant differences exist between the IVHTO and CWHTO groups in ΔKRA (0.8 ± 4.5° and -1.5 ± 6.5°; P = 0.631), ΔTTA (-3.9 ± 6.2° and -4.1 ± 7.3°; P = .951), ΔPT (-2.0 ± 4.8° and -0.6 ± 4.1°; P = .353), and ΔISR (0.0 and 0.0; P = .829). ΔTL in the IVHTO group (-1.6 ± 2.3 mm) was smaller compared with that in the CWHTO group (-4.1 ± 1.6 mm; P < .001).

CONCLUSIONS

(1) The postoperative PTS in the IVHTO group was further decreased compared to the CWHTO group; (2) no significant differences in ΔKRA, ΔTTA, ΔPT, and ΔISR exist between the 2 groups; and (3) the ΔTL in the IVHTO group was significantly smaller compared with the CWHTO group.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Editorial Commentary: An Inverted V-Shaped High Tibial Osteotomy Combining a Lateral Closing Wedge and Medial Opening Wedge May Have Advantages

High tibial osteotomy (HTO) is enjoying somewhat of a resurgence as a treatment for medial compartment arthritis with a varus deformity. An inverted V-shaped high tibial osteotomy (IVHTO), which is essentially a combined lateral closing-wedge high tibial osteotomy (CWHTO) and medial opening-wedge high tibial osteotomy (OWHTO), has some theoretical benefits over more conventional techniques. This also has been termed a combined HTO or a hemi-wedge osteotomy. After valgus correction is performed, the osteotomy is fixed with the bone wedge resected from the lateral side being inserted into the medial side. There may be a clinical advantage of an IVHTO over a CWHTO, and retrospective evidence has shown some postoperative radiologic differences between the techniques, but there are some inconsistencies between the studies. Proponents have argued that an IVHTO can correct a severe varus deformity more easily than a CWHTO, and that an IVHTO will not change the posterior tibial slope, the patellar height, or the length of the lower limb because the hinge point is located at the centre of rotation of angulation of the lower limb deformity. However, there may be disadvantages of this technique, including the technical difficulty of performing a precise inverted V-shaped osteotomy and the need to perform a fibular osteotomy, with the associated risk of peroneal nerve injury. Prospective clinical and radiological studies are needed, particularly comparing an IVHTO with an OWHTO, to help decide where the hinge of an HTO should be placed: lateral, medial, or central. My view is that the argument for adopting the IVHTO technique over other techniques is not yet persuasive, particularly as the IVHTO is more technically demanding than an OWHTO, my current preferred technique.

Discrepancy in the Distribution Patterns of Subchondral Bone Density Across the Ankle Joint After Medial Opening-Wedge and Lateral Closing-Wedge High Tibial Osteotomy

BACKGROUND

High tibial osteotomy (HTO) changes the alignment and dynamics of the ankle joint; however, differences in the stress distribution of the ankle joint after opening-wedge HTO (OWHTO) and closing-wedge HTO (CWHTO) are not understood. It is believed that subchondral bone density of the articular surface reflects the pattern of cumulative stress distribution across the joint surface.

PURPOSE

To clarify the effects of OWHTO and CWHTO on the distribution patterns of subchondral bone density across the ankle joint using computed tomography (CT)-osteoabsorptiometry.

STUDY DESIGN

Cohort study; Level of evidence, 4.

METHODS

Radiographic and CT data of 18 cases who underwent OWHTO (OW group), 12 cases who underwent CWHTO (CW group), and 11 cases with unilateral anterior cruciate ligament injury serving as controls were retrospectively reviewed. The subchondral bone density of the distal tibia was assessed in the 3 groups using CT-osteoabsorptiometry. The distal tibial surface of the ankle joint was divided into 4 parts in the coronal direction, and the percentage of the high-density area (%HDA) to each subregion was compared before and after HTO.

RESULTS

Preoperatively, comparing %HDA among the 3 groups, there were no significant differences in any regions. In the OW group, postoperative %HDA in the most medial region was significantly increased compared with preoperative %HDA (49.3% to 53.0%; P = .011), and postoperative %HDA in the most lateral region was significantly decreased (21.4% to 17.2%; P = .003). On the other hand, in the CW group, postoperative %HDA in the most medial region was significantly decreased (55.7% to 35.7%; P = .001), and %HDA in the second lateral region was significantly increased (23.6% to 29.2%; P = .002).

CONCLUSION

The ankle distribution pattern of subchondral bone density shifted significantly medially after OWHTO without fibular osteotomy, whereas the distribution pattern shifted laterally after CWHTO with fibular osteotomy. When the OWHTO is performed for patients with medial ankle osteoarthritis, surgeons should pay attention to potential postoperative progression of ankle osteoarthritis due to medial shift of the stress distribution in the ankle joint.

The difficulty of continuing sports activities after open-wedge high tibial osteotomy in patient with medial knee osteoarthritis: a retrospective case series at 2-year-minimum follow-up

Purpose

This study aimed to investigate the rate at which patients returned to sports after open wedge high tibial osteotomy and identify the continuity of sports activity post-operatively.

Methods

Thirty-five patients (40 knees) who underwent open-wedge high tibial osteotomy (OW-HTO) in medial knee osteoarthritis were included in this study. The mean age of the patients who underwent surgery was 55.1 ± 10.7 years, and the mean follow-up period was 41.0 ± 24.7 months. Clinical results and radiographic parameters calculated in standing whole-leg radiographs preoperatively, post-operatively, and at the final follow-up were evaluated.

Results

Thirty-one patients (88.6%) were able to return to preoperative sports activity; however, only 14 patients (40.0%) completely returned to preoperative sports activity levels. Of the 31 patients who returned to sports activity, 10 patients (32.3%) maintained post-operative sporting activity levels at the final follow-up. In radiographic parameters, the weight-bearing line ratio was considered loss of correction in the post-operative period leading to the final follow-up. Patients who completely returned to sports and maintained sporting activity levels at the final follow-up had significantly higher the Knee Injury and Osteoarthritis Outcome Score pain subscale values and lower visual analogue scale of knee pain at pre-surgery and final follow-up than other patients, including those who partially returned to sports.

Conclusions

The proportion of patients who returned to sports after OW-HTO and were able to participate in competitions at the same activity level as before surgery was low and insufficient.

Level of evidence

Retrospective case series, IV

Effect of High Tibial Osteotomy on the Distribution of Subchondral Bone Density Across the Proximal Tibial Articular Surface of the Knee With Medial Compartment Osteoarthritis

BACKGROUND

The effect of high tibial osteotomy (HTO) on the stress distribution across the knee joint is not completely understood. Subchondral bone density is considered to reflect the pattern of stress distribution across a joint surface.

PURPOSE

To assess the distribution of subchondral bone density across the proximal tibia in nonarthritic knees and in the knees of patients with osteoarthritis (OA) before and after HTO.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

We retrospectively collected radiological and computed tomography data from 16 patients without OA (control group) and 17 patients with OA. Data from the OA group were collected before and 1.5 years after HTO. Subchondral bone density of the proximal tibia was assessed with computed tomography-osteoabsorptiometry. The locations and percentages represented by high-density areas (HDAs) on the articular surface were quantitatively analyzed.

RESULTS

The ratio of the HDA of the medial compartment to the total HDA (medial ratio) was significantly higher in the preoperative OA group (mean, 80.1%) than in the control group (61.3%) (P < .001). After HTO, the medial ratio decreased significantly to 75.1% (P = .035 in comparison with preoperative values) and was significantly correlated with the hip-knee-ankle angle in both groups: control (r = -0.551; P = .033) and OA (r = -0.528; P = .043). The change in medial ratio after HTO was significantly correlated with the change in hip-knee-ankle angle (r = 0.587; P = .035). In the medial compartment, the HDA in the most lateral region of 4 subregions increased after HTO, but that in 3 medial subregions decreased.

CONCLUSION

In this exploratory study, HTO shifted the HDA of the medial compartment of the proximal tibial articular surface toward the lateral compartment. In contrast, the HDA of the most lateral region of the medial compartment increased after HTO. This change in subchondral bone density may result from the change in stress distribution.

An Acute Oblique Osteotomy and Suture Ligation Procedure to Shorten the Fibula in Lateral Closing-Wedge High Tibial Osteotomy

The purpose of this description is to report an "acute oblique osteotomy and ligation" (AOOL) procedure to shorten the fibula in high tibial osteotomy (HTO). A 4-cm longitudinal skin incision is made at the lateral aspect of the leg. After the central portion of the fibula is circumferentially isolated from all the periosteal tissues, a simple osteotomy is performed at the mid-portion of the fibular diaphysis in the quasi-frontal plane, which is inclined by 25 to 30° to the long axis of the fibula. Two thin holes are created beside the osteotomy line on the lateral surface of the fibula. A polyester thread is passed through the 2 holes. After the HTO is completed, the surgeon easily reduces the displaced fibular ends using this thread. This thread is securely tied to keep the contact between the 2 osteotomized surfaces. The AOOL procedure is technically easy and safely performed. We believe that the AOOL procedure is clinically useful to shorten the fibular shaft in HTO.

The Ability to Achieve a Specific Target Angle on Weightbearing Radiographs After Valgus High Tibial Osteotomy for Medial Knee Arthritis Is Not Predictable

Purpose

Standing radiographs are commonly used to plan angular correction in valgus tibial osteotomy for varus gonarthrosis. Most clinical studies have reported postoperative alignment as overall averages or means. The purpose of this study was to compare the preoperatively planned angle of correction measured on weight-bearing radiographs to the follow-up angle measured on weightbearing radiographs in individual patients 6 weeks after surgery and to analyze factors that could potentially affect achieving the planned degree of surgical correction. Our objective was to analyze factors potentially affecting the accuracy and ability to achieve the preoperatively planned correction angle (the target angle) in the individual patient.

Methods

We studied 35 tibial osteotomies (13 Coventry closing wedge osteotomies and 22 Maquet barrel vault osteotomies) performed for varus gonarthrosis between 1981 and 2019 to determine how accurately the target angle, based on preoperative standing weight-bearing radiographs, was achieved according to the postoperative radiographs in each individual. We reviewed 35 knees in 34 patients who had complete pre- and postoperative radiographs for review.

Results

Overall, only 14 of 35 (40%) of the patients were corrected to within ± 2° of the planned target angle. Valgus tibial osteotomy based on preoperative weightbearing radiographs is unpredictable in its ability to achieve the target angle on postoperative weightbearing radiographs when using either the Coventry or the Maquet surgical technique. The tendency was to undercorrect with either of the techniques. Larger (greater than 10°) preoperative varus alignment did not make it more difficult to achieve the target angle. Male or female sex and body mass index had no effect on the ability to achieve the target angle.

Conclusions

Valgus tibial osteotomy planning based on preoperative weightbearing is unpredictable in its ability to achieve the target angle on postoperative weightbearing radiographs. Overall, only 40% of our patients were corrected to within ± 2° of the planned target angle. The tendency was to undercorrect, with either the Coventry or the Maquet technique. Contrary to our hypothesis, larger preoperative varus alignment (greater than 10°) did not make it more difficult to achieve the target angle. The Coventry technique was as accurate as the Maquet technique.

Level of Evidence

Level IV.

Mid-term CT assessment of bone healing after nanohydroxyapatite augmentation in open-wedge high tibial osteotomy

BACKGROUND

The aim of the present study was to confirm the effectiveness of adding nanohydroxyapatite (NHA) to a heterologous bone graft in open-wedge high tibial osteotomy (OWHTO) by measuring the bone density via multislice computed tomography (CT) of the tibial osteotomy gap in a mid-term follow-up (five years).

METHODS

Twenty-six patients undergoing OWHTO were randomly assigned to two groups: a pure graft group (Group A), in which the osteotomy gap was filled with only heterologous bone graft, and an NHA group (Group B), in which the osteotomy gap was filled with heterologous bone graft and NHA. CT was performed within one week of the operation, after two months, after 12 months and after five years. CT volume acquired in Hounsfield units (HU) was measured on three planes.

RESULTS

The normal bone density was 110.2 ± 11.7 HU. The value of mean density at five years in Group A was 296.8 ± 81.8 HU, while in Group B, it was 202.2 ± 45.1 HU, showing a density more similar to normal bone and greater bone uniformity inside the osteotomy. The difference between the two groups was statistically significant (p < 0.05). Furthermore, both groups showed excellent mid-term clinical outcomes without significant differences.

CONCLUSIONS

This study revealed that absorbability and bone formation at the osteotomy site in the NHA group was significantly higher as compared with the pure graft group at five years postoperatively.

Clinical Outcomes and Complications During and After Medial Open-Wedge High Tibial Osteotomy Using a Locking Plate: A 3- to 7-Year Follow-up Study

Background:

Outcomes and complications at mid- or long-term follow-up after medial open-wedge high tibial osteotomy (MOWHTO) with the TomoFix locking plate have not been fully evaluated.

Purpose:

To evaluate the complications and midterm clinical outcomes after MOWHTO using a TomoFix.

Study Design:

Case series; Level of evidence, 4.

Methods:

Enrolled in this study were 80 patients (85 knees) who underwent MOWHTO with the TomoFix locking plate between 2009 and 2013. There were 66 women and 14 men, with a mean age of 61.5 years at the time of surgery. The diagnosis was medial osteoarthritis in 76 knees and spontaneous osteonecrosis of the knee in 9 knees. Metal removal and second-look arthroscopy were performed in all cases. Clinical and radiological examinations were performed at final follow-up after surgery (mean, 4.5 years).

Results:

The mean Japanese Orthopaedic Association score and Knee injury and Osteoarthritis Outcome Score improved significantly from pre- to postoperatively (P < .0001). The weightbearing line percentage shifted to pass through a point 67.7% lateral from the medial edge of the tibial plateau. The Caton-Deschamps index changed significantly from 0.88 to 0.66 at final follow-up (P < .0001). The mean posterior tibial slope changed significantly from 8.9° to 11.9° at final follow-up (P < .0001). Limb length was significantly increased after MOWHTO (10.3 mm; P < .0001). During plate removal, 14 locking screws were found to be broken in 9 knees (10.6%). The articular cartilage grade of the patellofemoral joint was significantly higher in the second arthroscopy than in the first arthroscopy (P < .0001). The cumulative rate of all complications was 41.2%, with major complications (ie, those requiring additional or extended treatment) in 24.7%.

Conclusion:

Postoperative outcome scores indicated significant improvement after MOWHTO, although the cumulative rate of all complications was 41.2% and the rate of major complications was 24.7%. These results indicate that MOWHTO with the TomoFix is a technically demanding procedure. Careful preoperative planning and meticulous surgical technique are needed to decrease the incidence of complications associated with MOWHTO.

Plate removal without loss of correction after open-wedge high tibial osteotomy is possible when posterior cortex bone union reaches osteotomy gap center even in incompletely filled gaps

PURPOSE

The study aimed to evaluate the optimal timing for plate removal after open-wedge high tibial osteotomy (OWHTO) without loss of correction and to investigate risk factors for loss of correction after plate removal. The study presents the hypothesis that plate removal without loss of correction was possible when gap filling reached zone 2 (25-50%) on anteroposterior radiographs.

METHODS

Ninety-one patients (101 knees) who underwent OWHTO using the TomoFix^® plate were enrolled. Plate removal was performed at an average 16.4 ± 5.4 months after OWHTO. Clinical evaluation included plate-related symptoms, the Japanese Orthopedic Association Knee Score (JOA score), and Oxford Knee Score (OKS). Radiological outcomes, including the hip-knee-ankle angle (HKA), weight-bearing line ratio (WBLR), medial proximal tibial angle (MPTA), and posterior tibial slope (PTS), were evaluated preoperatively, at plate removal and at 1 year after plate removal. Computed tomography (CT) was performed at plate removal to evaluate the flange bone union, progression rates of gap filling, and posterior cortex bone union. In addition, the risk factors for loss of correction after plate removal were evaluated.

RESULTS

At plate removal, 63 (62.4%) knees had plate-related symptoms (mild, 56 knees; moderate, 7 knees; severe, 0). After plate removal, the JOA score did not change, whereas OKS further improved; six knees developed loss of correction. On CT evaluation at plate removal, the flange bone union was achieved in all cases; the progression rates of gap filling and posterior cortex bone union were 47.0% ± 16.6% and 62.8% ± 16.5%, respectively. A posterior cortex union rate of < 43.3% was the only predictor for loss of correction after plate removal (odds ratio: 1.38, P < 0.01).

CONCLUSIONS

Plate removal without loss of correction after OWHTO was possible when bone union of the posterior cortex reached the center of the osteotomy gap even in incompletely filled gaps.

LEVEL OF EVIDENCE

Therapeutic case series, Level IV.

Assessment of valgus laxity after release of the medial structure in medial open-wedge high tibial osteotomy: an in vivo biomechanical study using quantitative valgus stress radiography

Background

To perform medial open-wedge high tibial osteotomy (OWHTO), surgeons expose the medial-proximal tibia by releasing or cutting the superficial layer of the medial collateral ligament (sMCL). Biomechanically, the sMCL provides primary restraint against valgus forces. Therefore, any release of the sMCL can cause valgus instability of the knee joint. The purpose of this study was to assess valgus laxity after release of the medial structure of the knee during OWHTO.

Methods

Between 2009 and 2015, 84 consecutive patients (93 knees) who underwent OWHTO using a locking plate were enrolled in this study. All patients underwent radiological examinations before surgery, during surgery, 1 year after surgery, and after plate removal to objectively assess valgus laxity. The medial joint space (MJS) and the joint line convergence angle (JLCA) of the knee were evaluated using quantitative valgus stress radiography. Clinical evaluation was performed 2 years after surgery.

Results

The mean functional knee score improved significantly, from 65.5 to 91.1 points (p < 0.0001). The mechanical axis percentage shifted to pass through a point 69.7% lateral from the medial edge of the tibial plateau. The MJS and JLCA increased significantly during OWHTO surgery (11.0 mm, 7.4 °, p < 0.0001). However, no significant differences were noted in the MJS and JLCA among preoperative, 1-year postoperative periods and after plate removal.

Conclusion

Valgus laxity was significantly greater after release of the sMCL. However, no significant differences were noted in valgus laxity in preoperative, 1-year postoperative periods and after plate removal. Complete release of the sMCL did not cause postoperative valgus laxity after OWHTO surgery.

Trial registration

Trial registration number: No.012–0360.

Comparison of Clinical and Radiologic Outcomes Between Normal and Overcorrected Medial Proximal Tibial Angle Groups After Open-Wedge High Tibial Osteotomy

PURPOSE

To evaluate whether the overcorrected medial proximal tibial angle (MPTA) affects the clinical outcomes after open-wedge high tibial osteotomy (OWHTO) and to assess the correlation between knee joint line obliquity (KJLO) changes and the compensatory changes in the hip and ankle joints.

METHODS

Consecutive patients who underwent OWHTO from July 2006 to August 2015 were included. Exclusion criteria were bilateral OWHTO and follow-up of <2 years. The patients were retrospectively divided into 2 groups according to postoperative MPTA; a normal group (MPTA <95°) and an overcorrected MPTA group (MPTA ≥95°). The groups were compared with respect to the clinical and radiologic outcomes after OWHTO. Clinical parameters, including Japanese Orthopedic Association (JOA) score, Oxford Knee Score (OKS), and Knee Injury and Osteoarthritis Outcome Score (KOOS), were evaluated. Radiologic outcomes, including the hip-knee-ankle angle (HKA), joint line convergence angle (JLCA), MPTA, KJLO, ankle joint line obliquity (AJLO), and hip abduction angle (HAA), were evaluated preoperatively and at the final follow-up.

RESULTS

Ninety-four patients (normal group; n = 52, overcorrected group; n = 42) were included in this study. After OWTHO, the mean increases in HKA and MPTA were 11.0° ± 3.2° and 10.4° ± 2.7°, respectively, whereas the change in KJLO was only 3.7° ± 2.9°. The mean AJLO (4.3 ± 3.9 to -1.3 ± 3.3, P < .001) and HAA (3.7 ± 2.5 to -1.1 ± 2.3, P < .001) significantly decreased after OWHTO. The mean postoperative MPTA in the overcorrected group was 96.9° ± 1.5°, whereas the mean postoperative KJLO was only 3.1° ± 2.0°. No significant differences were noted in all clinical scores between the groups at the final follow-up.

CONCLUSIONS

A certain degree of overcorrected MPTA (≥95°) did not affect the clinical outcomes after OWHTO because of compensatory changes in the hip and ankle joints.

LEVEL OF EVIDENCE

Level Ⅲ, retrospective comparative study.

Assessment of unloading effects after open wedge high tibial osteotomy using quantitative bone scintigraphy

INTRODUCTION

We evaluated changes in bone tracer uptake (BTU) in open wedge high tibial osteotomy (OWHTO) and determined if BTU correlates with clinical symptoms, postoperative alignment, or cartilage regeneration after OWHTO.

MATERIALS AND METHODS

Seventy-five knees in 64 patients who underwent OWHTO for medial compartment osteoarthritis were enrolled in this retrospective study. All cases were assessed preoperatively and at plate removal using bone scintigraphy. Visual analog scale (VAS), Japanese Orthopedic Association (JOA) score, Oxford Knee Score (OKS), Knee Injury and Osteoarthritis Outcome Score (KOOS), and the weight-bearing line ratio (WBLR) were assessed preoperatively and at plate removal. In addition, cartilage regeneration was evaluated at plate removal. We assessed changes in BTU for the medial and lateral compartment after OWHTO and the correlations between BTU of the medial compartment and all other parameters were analyzed.

RESULTS

Postoperatively, all outcome measures significantly improved: mean VAS 61.4 ± 18.3 to 9.5 ± 8.2, mean JOA score 65.1 ± 11.5 to 94.7 ± 6.0, mean OKS 29.4 ± 8.1 to 42.3 ± 4.1, mean KOOS 57.0 ± 14.3 to 83.7 ± 9.6, mean WBLR 22.8 ± 10.9 to 70.0 ± 9.4. Cartilage regeneration was observed in 53 knees (70.7%). BTU of the medial compartment significantly decreased after OWTHO, whereas no increased postoperative BTU was found in the lateral compartment. Postoperative BTU of the medial compartment significantly correlated with VAS, KOOS, and WBLR. No statistically significant associations were found between BTU and cartilage regeneration.

CONCLUSIONS

OWHTO significantly decreased BTU of the medial compartment, which correlated with knee pain and postoperative mechanical alignment. Unloading effects of OWHTO led to pain relief after surgery, regardless of cartilage regeneration.

Intra-articular platelet-rich plasma (PRP) injections for treating knee pain associated with osteoarthritis of the knee in the Japanese population: a phase I and IIa clinical trial

Intra-articular platelet-rich plasma (PRP) injection has been found to be effective for treating osteoarthritis in patients from Western countries; however, the safety and efficacy of PRP have not been sufficiently investigated in Japanese patients. The present study aimed to evaluate the safety and feasibility of intra-articular PRP injection in Japanese patients with knee osteoarthritis. PRP without white blood cells was prepared using a single-spin centrifuge (PRGF-Endoret; BTI Biotechnology Institute, Vitoria, Spain). A 6-mL PRP volume was injected in the knee joint three times at 1 week intervals. All patients were prospectively evaluated before intervention and at 1, 3, and 6 months after the treatment. Adverse events, the Visual Analog Scale (VAS) pain score, Japanese Knee Osteoarthritis Measure (JKOM) score and Japanese Orthopedic Association score were evaluated. Ten patients (all women; average age, 60.6 years) were treated. Only minor adverse events after injection were noted, and symptoms resolved within 48 hours after the injection. The average VAS pain scores were 71.6 mm and 18.4 mm at baseline and the 6-month follow-up, respectively (P < 0.05). At the 6-month follow-up, 80% of patients had a decrease in the VAS pain score of 50% or more. The average JKOM scores were 35.2 and 14.3 at baseline and at the 1-month follow-up, respectively (P < 0.05). Intra-articular PRP injection likely represents a safe treatment option for Japanese patients with mild-to-moderate knee osteoarthritis, and has the potential to relieve pain for up to 6 months, but further study is needed to verify the efficacy.

Inverted V-Shaped High Tibial Osteotomy for Medial Osteoarthritic Knees With Severe Varus Deformity

A hemi-closing-wedge and hemi-opening-wedge, inverted V-shaped high tibial osteotomy with local bone graft has been reported to be an effective surgical procedure for medial osteoarthritis of the knee. In this procedure, an inverted V-shaped osteotomy is made and a thin wedged bone block is resected from the lateral side and implanted in the medial opening space created after valgus correction. This procedure can provide sufficient valgus correction of the knee with severe varus deformity more easily than can closing-wedge high tibial osteotomy. The inverted V-shaped osteotomy does not change the posterior tibial slope, the patellar height, or the length of the lower limb at all because the center of tibial alignment correction by the inverted V-shaped osteotomy is located near the center of rotation of angulation of the lower-limb deformity. We recently modified this procedure by performing biplanar osteotomy, developing useful cutting guides, and fixing the tibia with a lateral locking compression plate. The surgical technique is described to enable the reproducible creation of the hemi-closing-wedge and hemi-opening-wedge, inverted V-shaped osteotomy with the locking plate for medial osteoarthritic knees with moderate or severe varus deformity.

Inverted V-shaped high tibial osteotomy for severe tibia vara associated with Turner syndrome: A case report and review of literature

•

Severe cases of genu varum represent a major challenge in obtaining normal alignment.

•

We performed inverted V-shaped HTO in a patient with Turner syndrome.

•

Inverted V-shaped HTO can be a useful surgical method to treat severe tibia vara.

Introduction

Severe cases of genu varum represent a major challenge in obtaining normal configuration of the proximal tibia and overall limb alignment.

Presentation of case

We performed inverted V-shaped high tibial osteotomy (HTO) by using a locking plate for recurrent severe bilateral tibia vara in a 15-year-old female patient with Turner syndrome. Preoperative medial proximal tibial angle (MPTA) and standing femorotibial angle (FTA) of the right/left legs were 67°/69° and 197°/203°, respectively. In order to obtain overall neutral alignment, the correction angle in the right/left knees was required to be 23°/32°. Preoperative planning demonstrated that inverted V-shaped HTO could provide sufficient correction angle with large bone stock and wide bony contact. A postoperative full-standing radiograph showed that the mechanical axes passed through the center of right/left knees with 87°/88° of MPTA.

Discussion

Inverted V-shaped HTO has advantages, as it requires a smaller amount of bone resection and smaller opening gap compared to the closing-wedge and opening-wedge osteotomies.

Conclusion

Inverted V-shaped HTO can be a useful surgical method to treat severe tibia vara in order to obtain adequate configuration of the proximal tibia and overall limb alignment.

Patellofemoral Osteoarthritis Progression and Alignment Changes after Open-Wedge High Tibial Osteotomy Do Not Affect Clinical Outcomes at Mid-term Follow-up

PURPOSE

To evaluate the clinical and radiological outcomes of open-wedge high tibial osteotomy (OWHTO) with respect to the patellofemoral joint and to assess whether patellofemoral osteoarthritis (OA) progression and alignment changes after OWHTO affect clinical outcomes.

METHODS

Inclusion criteria were consecutive patients who underwent OWHTO from March 2005 to September 2013. Exclusion criteria were loss to follow-up within 2 years and absence of second-look arthroscopy findings at the time of plate removal. The clinical parameters, including anterior knee pain while climbing stairs, Japanese Orthopedic Association score, and Oxford Knee Score, were evaluated. Radiological outcomes, including weight-bearing line ratio, modified Blackburne-Peel ratio, posterior tibial slope, tilting angle, lateral shift ratio, and patellofemoral OA (Kellgren-Lawrence grade), were evaluated preoperatively and at the final follow-up. Cartilage status (International Cartilage Repair Society grade) was evaluated at the initial HTO and at plate removal.

RESULTS

Fifty-three patients (60 knees) were included in this study. The mean follow-up was 58.2 ± 22.4 months. Two knees (3%) presented with mild anterior knee pain after OWHTO. The mean Japanese Orthopedic Association score (66.9 ± 11.2 to 91.2 ± 9.7) significantly improved (P < .001), and the mean Oxford Knee Score at the final follow-up was 42.0 ± 5.3. The mean modified Blackburne-Peel ratio (0.9 ± 0.1 to 0.7 ± 0.1, P < .001) and tilting angle (6.8 ± 3.7 to 5.6 ± 3.4, P = .033) significantly decreased after OWHTO, whereas no significant changes in posterior tibial slope (P = .511) and lateral shift ratio (P = .522) were observed. Radiologically, patellofemoral OA had progressed in 15 knees (27%), and arthroscopically patellofemoral cartilage degeneration had progressed in 27 knees (45%). However, there was no significant correlation between changes in patellofemoral alignment and clinical outcomes.

CONCLUSIONS

Changes in patellofemoral alignment and patellofemoral OA progression did not affect the clinical outcomes of OWHTO at mid-term follow-up.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Age does not affect the clinical and radiological outcomes after open-wedge high tibial osteotomy

PURPOSE

Open-wedge high tibial osteotomy (OWHTO) is a well-established procedure in the management of medial compartment osteoarthritis and osteonecrosis of the medial femoral condyle. Several studies have evaluated factors that negatively influence outcomes. However, few reports have investigated the effect of age on HTO outcome. We evaluated the influence of the age on the outcome after HTO.

METHODS

The TomoFix^® plate was used to perform 60 consecutive OWHTOs. Twenty-six knees in 23 patients >65 years old (mean age at surgery 68.7 ± 2.9 years; range 65-75 years, group A) were compared with 34 knees in 27 patients <65 years old (mean age at surgery 56.2 ± 7.5 years; range 38-64 years, group B) with respect to the clinical and radiological outcomes after HTO. The clinical evaluation included the Japanese Orthopedic Association Knee Score (JOA score), Oxford Knee Score (OKS) and complications after surgery.

RESULTS

There were no statistical differences in the background factors between the two groups. Postoperatively, the mean JOA score showed a significant improvement in both groups. The mean OKS after surgery was 41.6 ± 5.9 in group A and 41.4 ± 5.9 in group B. There were no statistical differences in the postoperative knee alignment and clinical outcomes between the two groups.

CONCLUSION

OWHTO using the rigid long plate was an effective procedure independent of patient's age. The results showed that age did not influence the clinical and radiological outcomes after OWHTO.

Bone grafts and bone substitutes for opening-wedge osteotomies of the knee: a systematic review

PURPOSE

To establish the rate of use of various void fillers in the setting of opening-wedge osteotomy around the knee, the types of fixation used, and the rates of delayed union or nonunion related to these variables. In addition, this review addressed short-term to midterm outcomes and complication rates associated with such procedures.

METHODS

The electronic databases Medline, Embase, and PubMed were searched using the methodology for systematic review as recommended by the Cochrane Collaboration. The search terms used were as follows: knee, osteotomy, knee joint, bone grafting, opening osteotomy, opening wedge, tibial osteotomy, femoral osteotomy, and bone substitute. We screened 1,383 articles and applied exclusion criteria. Fifty-six articles were included.

RESULTS

We included 3,033 cases of osteotomy in 2,910 patients. The mean age of patients was 50 years, with a mean follow-up period of 42 months. Male patients comprised 52% of patients. The mean alignment change was 10.8°, shifting the mechanical axis to 5.1° valgus. Delayed union/nonunion rates were 2.6%, 4.6%, and 4.5% for autograft, allograft bone, and synthetic bone substitutes, respectively (P = .03). Delayed union/nonunion rates were significantly lower for autograft compared with allograft (P = .03) and for autograft and allograft compared with synthetic bone substitutes (P < .0001). Non-locking plates (n = 2,148) had a rate of delayed union/nonunion of 3.7% and a mean loss of correction over time of 0.5°. Locking plates (n = 681) had a rate of delayed union/nonunion of 2.6% and a loss of correction of 2.3°. All mean knee outcome scores improved, and an overall complication rate of 14% was found.

CONCLUSIONS

Opening-wedge osteotomy had good short-term to midterm outcomes with acceptable complication rates. The lowest rates of delayed union/nonunion were in autograft bone-filled osteotomies. Plate type does not appear to affect osteotomy union or loss of correction.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I to IV studies.

Beta-tricalcium phosphate shows superior absorption rate and osteoconductivity compared to hydroxyapatite in open-wedge high tibial osteotomy

PURPOSE

The purpose of this study was to clinically and radiologically compare the utility, osteoconductivity, and absorbability of hydroxyapatite (HAp) and beta-tricalcium phosphate (TCP) spacers in medial open-wedge high tibial osteotomy (HTO).

METHODS

Thirty-eight patients underwent medial open-wedge HTO with a locking plate. In the first 19 knees, a HAp spacer was implanted in the opening space (HAp group). In the remaining 19 knees, a TCP spacer was implanted in the same manner (TCP group). All patients underwent clinical and radiological examinations before surgery and at 18 months after surgery.

RESULTS

Concerning the background factors, there were no statistical differences between the two groups. Post-operatively, the knee score significantly improved in each group. Concerning the post-operative knee alignment and clinical outcome, there was no statistical difference in each parameter between the two groups. Regarding the osteoconductivity, the modified van Hemert's score of the TCP group was significantly higher (p = 0.0009) than that of the HAp group in the most medial osteotomy zone. The absorption rate was significantly greater in the TCP group than in the HAp group (p = 0.00039).

CONCLUSIONS

The present study demonstrated that a TCP spacer was significantly superior to a HAp spacer concerning osteoconductivity and absorbability at 18 months after medial open-wedge HTO.

LEVEL OF EVIDENCE

Retrospective comparative study, Level III.

The long-term outcome of open-wedge osteotomy of the proximal tibia with hemicallotasis

We report the long-term outcome of 33 patients (37 knees) who underwent proximal tibial open-wedge osteotomy with hemicallotasis (HCO) for medial osteoarthritis of the knee between 1995 and 2000. Among these, 29 patients with unilateral HCO were enrolled and 19 were available for review at a mean of 14.2 years (10 to 15.7) post-operatively. For these 19 patients, the mean Hospital for Special Surgery knee score was 60 (57 to 62) pre-operatively and 85 (82 to 87) at final follow-up (p < 0.001; paired t-test). The femorotibial angle and tibial inclination angle (IA) were measured at short-term follow-up, one to four years post-operatively, and showed no significant subsequent changes. The clinical scores and radiological measurements showed little change over time. One patient required conversion to total knee replacement during this time. These results suggest that the coronal angle achieved at operation is maintained at long-term follow up after HCO without alteration of the IA, providing a good long-term clinical outcome.

Cite this article: Bone Joint J 2014;96-B:467–72.

Metal block augmentation for bone defects of the medial tibia during primary total knee arthroplasty

Background

Stable and well-aligned placement of tibial components during primary total knee arthroplasty is challenging in patients with bone defects. Although rectangular block-shaped augmentations are widely used to reduce the shearing force between the tibial tray and bone compared with wedge-shaped augmentations, the clinical result remains unclear. This study aimed to evaluate the outcome of primary total knee arthroplasty with metal block augmentation.

Methods

We retrospectively reviewed the 3- to 6-year follow-up results of 33 knees that underwent total knee arthroplasty with metal block augmentation (metal-augmented group) for bone defects of the medial tibia and 132 varus knees without bone defects as the control group. All surgeries were performed using posterior-stabilized cemented prostheses in both groups. Cemented stems were routinely augmented when the metal block was used.

Results

There were no differences in implant survival rates (100% in metal-augmented and 99.2% in control) or knee function scores (82 points in metal-augmented and 84 points in control) between the two groups at the final follow-up examination (P = 0.60 and P = 0.09, respectively). No subsidence or loosening of the tibial tray was observed. Of 33 metal-augmented total knee arthroplasties, a nonprogressive radiolucent line beneath the metal was detected in 10 knees (30.3%), and rounding of the medial edge of the tibia was observed in 17 knees (51.5%).

Conclusions

The clinical results of total knee arthroplasty with metal augmentation were not inferior to those in patients without bone defects. However, radiolucent lines were observed in 30.3%.

The effect of proximal tibial corrective osteotomy on menisci, tibia and tarsal bones: a finite element model study of tibia vara

BACKGROUND

Proximal tibial open wedge osteotomy (PTO) is a corrective operation used in the surgery of lower extremities and is applied to patients with varus deformities for sufficient correction. The aim of the study was to evaluate whether the PTO can achieve decreased stress-bearing on the tibia and tarsal bones in addition to correcting the mechanical axis of the lower limb in patients with tibia vara.

METHODS

Three-dimensional (3D) solid modelling of the lower extremity was carried out using computed tomography (CT) and magnetic resonance (MR)-containing images of all of the bony elements and non-bony structures. PTO was applied to the obtained deformed model in the computer environment and the correction was carried out.

RESULTS

Stress distributions in menisci, tibia and tarsal bones were calculated. With respect to loading on the tarsal bones, the maximum equivalent stresses on all bones decreased except for the navicula in the PTO-simulated model in the current study.

CONCLUSION

These results clearly indicate that PTO can achieve decreased stresses on the tarsal bones in patients with tibia vara.

Survival and clinical outcome of isolated high tibial osteotomy and combined biological knee reconstruction

PURPOSE

We sought to determine survival and clinical outcomes of high tibial osteotomy (HTO) with or without articular cartilage surgery and/or meniscal allograft transplantation in patients with medial compartment chondral pathology, varus malalignment, and/or meniscal deficiency, whether there is any difference in survival or clinical outcome between these patient cohorts, and whether there is any difference between opening- (OWHTO) and closing-wedge (CWHTO) techniques.

METHODS

A systematic review of multiple medical databases was performed using PRISMA guidelines. Study quality was assessed via modified Coleman Methodology Scores (MCMS).

RESULTS

Sixty-nine studies were included (4557 subjects). MCMS rating was overall poor. Mean follow-up was 7.1 years. Mean subject age was 53 years. Survival of isolated HTO was 92.4%, 84.5%, 77.3%, and 72.3% at 5, 10, 15, and 20 years of follow-up. At 5 years of follow-up, HTO with articular cartilage surgery had significantly greater survival (97.7%) than either isolated HTO (92.4%) or HTO with MAT (90.9%). Isolated HTO, HTO with articular cartilage surgery, and HTO with MAT all significantly improved subjective and objective clinical outcome scores. At two years of follow-up, survival was significantly greater following OWHTO (98.7%) versus CWHTO (96.7%). However, at all other time points with or without combined articular cartilage surgery and/or MAT, there was no significant survival difference between the techniques.

CONCLUSIONS

Survival and clinical outcomes of isolated HTO were excellent at short- and mid-term follow-ups, but deteriorated with time. HTO with concomitant procedures also demonstrated excellent early survival and clinical outcomes that deteriorated with time (up to 10 years).

The impact of a high tibial valgus osteotomy and unicondylar medial arthroplasty on the treatment for knee osteoarthritis: a meta-analysis

PURPOSE

Both high tibial valgus osteotomy (HTO) and unicompartmental medial knee arthroplasty (UKA) are established methods for the treatment for moderate stages of OA. This is the first global meta-analysis to compare the long-term effects of both methods regarding survival, outcomes and complications of total arthroplasty.

METHODS

Literature research was performed using established medical databases: MEDLINE (via PubMed), EMBASE (via OVID) and the Cochrane register. Criteria for inclusion were as follows: English or German papers, a clinical trial with a clear description of survival, an outcome evaluation using a well-described knee score and a follow-up >5 years. Statistical analysis was performed using the special meta-analysis software called "Comprehensive Meta Analysis" (version 2.0; Biostat, Englewood, NJ, USA).

RESULTS

Final meta-analysis after the full-text review included 46 studies about valgus HTO and 43 studies about medial UKA. There were no significant differences between valgus HTO and medial UKA in terms of the number of total required replacements. After a 5- to 8-year follow-up, 91.0% of the valgus HTO patients and 91.5% of medial UKA patients did not need a total replacement. This value was 84.4% for valgus HTOs and 86.9% for medial UKAs after a 9- to 12-year follow-up. Mean survival time to TKA was 9.7 years after valgus HTO and 9.2 years after medial UKA. Clinical outcome was significantly better after medial UKA in a 5- to 12-year follow-up. After more than 12 years, results were comparable in both groups. No significant differences were seen in the complication rates.

CONCLUSIONS

This meta-analysis aimed to find the advantages and disadvantages of two established methods for the treatment for medial compartment knee osteoarthritis. Valgus HTO is more appropriate for younger patients who accept a slight decrease in their physical activity. Medial UKA is appropriate for older patients obtaining sufficient pain relief but with reduced physical activity.

LEVEL OF EVIDENCE

II.

Anterior posterior inverted-'U' osteotomy for tibia vara: technique and early results

BACKGROUND

Blount disease often requires operative treatment including osteotomy. This study evaluated the safety and outcome of the inverted-U osteotomy in Blount disease.

METHODS

We performed an anteroposterior inverted-U osteotomy without a jig or image intensifier in the treatment of a series of 31 children with the intention of achieving anterior-posterior stability at the osteotomy site without risk of major neurological and vascular injuries.

RESULTS

We found no vascular or common peroneal nerve injury. There was stability at the osteotomy site without the need for internal fixation. Thirty knees in 20 patients had good outcome, while 17 knees (11 patients) had fair outcome.

CONCLUSIONS

Our results suggest that this technique is safe, effective and gives satisfactory outcome in the operative correction of Blount's disease.

Clinical results of reversed V-shaped high tibial corticotomy with minimally invasive surgery without internal fixation devices

High tibial osteotomy is a method of treating knee osteoarthritis due to genu varum in advanced stages. High tibial osteotomy-associated problems continue to be reported. The purpose of this study was to investigate the clinical results of a new, innovative method of high tibial osteotomy with 3- to 13-year follow-up. Between 1996 and 2006, our new surgical method was performed on 293 patients with medial compartment osteoarthritis and genu varum. All patients were examined preoperatively, 6 months postoperatively, and at final follow-up. The Hospital for Special Surgery Knee Scoring System (HSS) was used at final follow-up, and limb alignment and patient satisfaction were reassessed. Immediate postoperative complications included varus recurrence, knee instability, and peroneal nerve palsy, and no signs of tibial nonunion or infection were observed. At final follow-up, 3 cases of genu recurvatum, 2 cases of peroneal nerve palsy, and 25 cases of loss of correction were observed. Average postoperative HSS score was 85 (range, 47-97), and 97.8% of the patients were satisfied. This new method is a good alternative for the correction of genu varum because it requires a small incision, is soft tissue friendly, is a corticotomy instead of an osteotomy, requires no internal or external fixation devices, has a shorter duration and an acceptable complication and recurrence rate, and results in satisfactory HSS scores and higher patient satisfaction rates.

The short-term follow-up results of open wedge high tibial osteotomy with using an Aescula open wedge plate and an allogenic bone graft: the minimum 1-year follow-up results

Background

This study examined the results of open wedge high tibial osteotomy with using an Aescula open wedge plate and an allogenic bone graft as a surgical technique for the patients who suffer from osteoarthritis of the knee with a genu varum deformity.

Methods

From March 2007 to August 2007, 33 patients (37 cases) with osteoarthritis of the knee and a genu varum deformity underwent a high tibial osteotomy with using an Aescula open wedge plate and an allogenic bone graft. The patients were followed up for more than 1 year. Before and after surgery, the correction angle of the genu varum was measured by the lower extremity scannogram and the posterior tibial slope, the joint space distance and the time to bone union were evaluated. The functional factors were evaluated using the Knee Society Score.

Results

The average knee score and function score improved from 52.19 ± 11.82 to 92.49 ± 5.10 and 52.84 ± 6.23 to 89.05 ± 5.53, respectively (p < 0.001). According to the lower extremity scannogram, the mean preoperative varus angle was -1.86 ± 2.76°, and the average correction angle at the last follow-up was 10.93 ± 2.50° (p < 0.001). The tibial posterior slope before surgery and at the last follow-up were 8.20 ± 1.80° and 8.04 ± 1.30°, respectively (p = 0.437). The joint space distance increased from 4.05 ± 1.30 mm to 4.83 ± 1.33 mm (p < 0.001). The average time to complete bone union was 12.69 ± 1.5 weeks.

Conclusions

An open wedge high tibial osteotomy using an Aescula open wedge plate and an allogeneic bone graft to treat osteoarthritis of the knee with a genu varum deformity showed good results for the precision of the correction angle, the time to bone union and the functional improvement.

Staple versus locking compression plate fixation after lateral closing wedge high tibial osteotomy

PURPOSE

To compare the results of staple versus locking compression plate fixation after closing wedge high tibial osteotomy.

METHODS

A group of 23 patients (24 knees) who underwent box high tibial osteotomy and staple fixation was compared with another group of 19 patients (22 knees) who underwent a similar procedure but with locking compression plate fixation. Both groups were followed up for 3 years. The range of movement, Hospital for Special Surgery (HSS) Knee Score, time to full weight bearing, incidence of delayed union, femorotibial angle, and stage of osteoarthritis were compared.

RESULTS

At 6 months after the operation, the median HSS score and the proportion of patients with excellent or good scores were significantly higher in the locking compression plate than the staple fixation group (76 vs 62, p=0.003; 75% vs 42%, p=0.0354), but not at one and 3 years. The range of movement was significantly greater in the locking compression plate fixation group in the short term (6 weeks, 3 and 6 months), but not after one year. The median time to full weight bearing was significantly shorter in the locking compression plate fixation group (86 vs 116 days, p<0.001). There were fewer delayed unions in the locking compression plate fixation group but not significantly (1 vs 5, p=0.198), possibly because of the small numbers involved. There was no difference, within the limits of measurement error, in the femorotibial angle or correction loss between the 2 groups.

CONCLUSION

Locking compression plate fixation obviates the use of plaster casts, enables early mobilisation and bone union, and reduces the numbers with delayed union and the time to full weight bearing. Longer-term studies are needed to evaluate its effect on revarisation and arthropathy.

Bone formation and resorption in patients after implantation of beta-tricalcium phosphate blocks with 60% and 75% porosity in opening-wedge high tibial osteotomy

Most of the implanted porous beta-tricalcium phosphate (beta-TCP) can be resorbed. However, beta-TCP block with 75% porosity is inadequate for weight-bearing sites until bone incorporation occurs. Thus, the authors have recently developed beta-TCP block with 60% porosity, which is approximately sevenfold greater in terms of compressive strength than that of beta-TCP with 75% porosity. The authors investigated bone formation and resorption of beta-TCP after implantation in patients of beta-TCP blocks with two different porosities. From May 2003 to November 2004, medial opening high tibial osteotomy was performed in 25 patients with a mean age of 66 years. The opened defect was fixed with a Puddu plate. Then 6-8 cm(3) of beta-TCP block with 75% porosity was used to fill the cancellous bone defect, except on the medial side where 2.83-3.18 cm(3) of wedge-shaped beta-TCP block with 60% porosity was implanted. At least 2 years after surgery, the 25 patients had no correction loss, and bone formation was noted in all cases. Complete or nearly complete resorption of beta-TCP with 60 and 75% porosity was obtained within 3.5 years. Thirteen biopsy samples obtained from the 60% porosity implantation sites showed good lamellar bone formation, and the percentage of beta-TCP remaining relative to the newly formed bone plus beta-TCP ranged from 0.3 to 14.5%, with a mean of 6.7%. The authors suspect that mechanical stress loading to the medial side of the tibia facilitated bone formation and resorption of beta-TCP with 60% porosity.

High tibial closing wedge osteotomy for medial compartment osteoarthrosis of knee

BACKGROUND

Most patients of symptomatic osteoarthrosis of knee are associated with varus malalignment that is causative or contributory to painful arthrosis. It is rational to correct the malalignment to transfer the functional load to the unaffected or less affected compartment of the knee to relieve symptoms. We report the outcome of a simple technique of high tibial osteotomy in the medial compartment osteoarthrosis of the knee.

MATERIALS AND METHODS

Between 1996 and 2004 we performed closing wedge osteotomy in 78 knees in 65 patients. The patients selected for osteotomy were symptomatic essentially due to medial compartment osteoarthrosis associated with moderate genu varum. Of the 19 patients who had bilateral symptomatic disease 11 opted for high tibial osteotomy of their second knee 1-3 years after the first operation. Preoperative grading of osteoarthrosis and postoperative function was assessed using Japanese Orthopaedic Association (JOA) rating scale.

RESULTS

At a minimum follow-up of 2 years (range 2-9 years) 6-10 degrees of valgus correction at the site of osteotomy was maintained, there was significant relief of pain while walking, negotiating stairs, squatting and sitting cross-legged. Walking distance in all patients improved by two to four times their preoperative distance of 200-400 m. No patient lost any preoperative knee function. The mean JOA scoring improved from preoperative 54 (40-65) to 77 (55-85) at final follow-up.

CONCLUSION

Closing wedge high tibial osteotomy performed by our technique can be undertaken in any setup with moderate facilities. Operation related complications are minimal and avoidable. Kirschner wire fixation is least likely to interfere with replacement surgery if it becomes necessary.