Computer-assisted navigation decreases the change in the tibial posterior slope angle after closed-wedge high tibial osteotomy

Surgical accuracy of coronal and sagittal alignment in conventional closed-wedge high tibial osteotomy after computer-assisted surgery experience

BACKGROUND

Although intraoperative navigation can improve the surgeon's proficiency, no studies have analyzed postoperative outcomes of high tibial osteotomy (HTO) after computer-assisted surgery (CAS) experience. The present study compared the clinical and radiographic results between conventional and CAS closed-wedge (CW) HTOs after CAS experience.

METHODS

Each of the 50 conventional and CAS CW HTOs performed by single surgeon between 2015 and 2017 were included. The surgeon had experience of 140 cases of CAS CW HTOs before the study period. The groups were not different in terms of demographics. Clinically, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and range of motion (ROM) were investigated. Radiographically, the mechanical axis (MA), change in posterior tibial slope angle (PTS), and parallel angle were evaluated. The proportions of inlier groups for the postoperative MA (within valgus 2° ± 3°), change in the PTS (within ± 3°), and parallel angle (< 3°) were compared.

RESULTS

There were no significant differences in postoperative clinical results between the conventional and CAS groups. The MA was appropriately corrected in both groups (2.4° versus 2.9°, p = 0.317). The amount of change in PTS was significantly greater in the conventional group (-2.2° versus -0.8°, p = 0.018). The parallel angle was 5.3° in the conventional groups and 3.1° in the CAS group (p = 0.003). The proportion of inlier group was not significantly different in the postoperative MA (72% versus 78%) and change in the PTS (52% versus 66%). The proportion of inlier for the parallel angle was significantly lower in the conventional group (36% versus 60%, p = 0.027).

CONCLUSIONS

The surgical proficiency after CAS experience could cover the advantages of an intraoperative navigation in coronal adjustment, not in the sagittal adjustments in CW HTOs. A larger cohort with multiple surgeons in multiple centers would be required to identify the general trend.

STUDY DESIGN

Level of evidence III.

Comparison of computer-assisted navigated technology and conventional technology in high tibial osteotomy (HTO): a meta-analysis

BACKGROUND

Though some studies have reported navigated high tibial osteotomy (HTO) is a useful procedure to correct knee deformity. There is still great controversy whether navigated HTO can achieve better accuracy of limb alignment and greater clinical outcomes. Current meta-analysis was conducted to investigate whether better radiographic outcomes and clinical outcomes could be acquired in navigated HTO compared with the conventional procedure.

METHOD

We conducted a literature search in the electronic databases, including Medline, Embase, the Cochrane Library, and Web of Science. We identified studies published before August 2020. We also checked the references of the related articles for any relevant studies. We strictly followed the Preferred Reporting Items for Systematics reviews and Meta-Analysis (PRISMA) guidelines in this review. This research was performed using Review Manager 5.4 software.

RESULTS

Fourteen articles were included, involving 1399 knees. Our meta-analysis indicated that patients undergoing navigated HTO had significantly better outcomes in outliers of aimed limb alignment (RD=-0.24, 95% CI: =-0.34 to -0.13, p < 0.01), outliers of aimed tibial posterior slope (TPS) (RD=-0.41, 95% CI: -0.51 to -0.30, p < 0.01), Range of Motion (ROM) (MD = 6.37, 95%CI: 0.83-11.91, p = 0.02), and American knee society knee score (AKS knee score) (MD = 3.88, 95%CI: 1.37-6.39, p = 0.002). No significant differences were found in Lysholm score (MD = 1.30, 95%CI: -0.31 to 2.90, p = 0.11), American knee society function score (AKS function score) (RD = 1.42, 95%CI: -0.15 to 2.99, p = 0.08), complications (RD=-0.01, 95% CI: = -0.05 to 0.04, p = 0.77), delayed union (RD=-0.01, 95% CI: = -0.02 to 0.03, p = 0.59), and reoperation (RD = 0, 95% CI: -0.09 to 0.10, p = 0.98) between the two groups. The operation time in the navigated group was 15.46 min longer than in the conventional group.

CONCLUSION

Navigated HTO provided more accurate and reproducible radiographic outcomes in the correction of the malalignment than conventional techniques, and there is no difference in the risk of complications compared with conventional HTO. However, it is unclear whether navigation HTO can achieve better clinical results. More randomized controlled trials (RCTs) with high quality, large sample size, and sufficient follow-up period are required.

Clinical Usefulness of SPECT/CT for Assessing Postoperative Outcomes After Medial Opening-Wedge High Tibial Osteotomy

Background:

Qualitative studies have explored changes in Tc-99m hydroxymethylene diphosphonate (HDP) uptake on single-photon emission computed tomography and computed tomography (SPECT/CT) as a result of offloading after medial opening-wedge high tibial osteotomy (MOWHTO) in patients with medial compartment knee osteoarthritis. However, whether changes in the Tc-99m HDP uptake on SPECT/CT reflect the degree of clinical improvement in postoperative outcomes, especially when using minimal clinically important differences (MCIDs), has not been investigated.

Purpose:

To investigate the association between changes in Tc-99m HDP uptake on SPECT/CT and MCID-based improvement on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score in patients who underwent MOWHTO.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

The study included 35 knees in 31 patients who underwent MOWHTO. SPECT/CT was performed preoperatively and 3 years postoperatively with clinical and radiological assessments. On SPECT/CT, the knee joint was divided into 10 regions, and the radiotracer uptake amount of each region was divided by the uptake amount of the reference zone. Patients were divided into 2 groups based on whether they achieved the MCID of 16.1 points on the WOMAC at 3 years postoperatively, and changes in uptake amount on SPECT/CT were compared between the groups.

Results:

At 3 years postoperatively, 22 patients achieved the MCID on the WOMAC (62.9%; above-MCID group) and 13 patients did not (37.1%; below-MCID group). In the above-MCID group, significant improvement was observed in the WOMAC after MOWHTO (from 55.8 to 19.6; P < .05); however, significant improvement was not observed in the below-MCID group (from 38.8 to 32.3; P = .100). Based on mean change of uptake on SPECT/CT in each region, the above-MCID group showed significantly greater reduction of uptake on SPECT/CT than the below-MCID group in the femoral anteromedial compartment (P = .004), tibial anteromedial compartment (P = .009), and tibial anterolateral compartment (P = .031).

Conclusion:

Reduction in radiotracer uptake on SPECT/CT of the knee joint reflected clinical improvement in patient-reported outcomes following MOWHTO.

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.

Effect of the amount of correction on posterior tibial slope and patellar height in open-wedge high tibial osteotomy

Objectives: To evaluate the effect of amount of correction on postoperative changes in PTS (posterior tibial slope), PH (patellar height), and clinical outcomes following biplanar OWHTO (open-wedge high tibial osteotomy). Method: This study included 79 knees (32 left and 47 right) of 79 patients (mean age 60.28 ± 4.2 years, 24 males, 55 females) with varus malalignment and symptomatic isolated medial joint osteoarthritis who underwent OWHTO. According to the amount of correction angles, all patients were divided into three groups: LCA (large correction angle) group (>14°), MCA (medium correction angle) group (10°-14°), and SCA (small correction angle) group (<10°). All patients were clinically assessed according to the Lysholm score, HSS (hospital for special surgery knee score), and KSS (knee society score) prior to and after surgery. For radiographic analysis, we measured the PTS, PH [ISI (Insall-Salvati index), and BPI (Blackburne-Peel index)]. The pre-post difference of PTS, ISI, and BPI was calculated by subtracting the post-OWHTO value to the pre-OWHTO value in three groups, respectively. The preoperative, postoperative, and difference of PTS, ISI, and BPI values were analyzed according to the correction angle. The mean follow-up period was 28.5 months (SD, 4.9; range 18-52 months). Results: Radiologically, PTS increased and PH decreased after surgery on the whole (p < .05). The relationship between amount of correction and slope increase is significant (p < .001). Furthermore, the pairwise difference between the LCA group and SCA group and MCA group is significant respectively (p < .05). In terms of PH, the LCA group yielded ISI and BPI that were significantly different from baseline for the SCA group and MCA group. In addition, the pairwise difference between the SCA group and LCA group in ISI and BPI is significant (p = .031). Clinically, significant improvements were observed in postoperative clinical scores of the Lysholm score, HSS, and KSS (p < .05). Seventy-four patients (93.67%) reported satisfaction with surgery. However, no correlation was found between changes in PTS and PH with postoperative knee score. No severe adverse complications were observed. Conclusions: The amount of correction angle is a significant factor affecting the PTS and PH in OWHTO. With increased correction angle, the likelihood of increasing the PTS and decreasing the PH increases. Special attention should be paid to keep PTS and PH unchanged in cases where large corrections are required. Otherwise, closing wedge osteotomy or other intraoperative effective measures are supposed to be adopted.

Adding a protective K-wire during opening high tibial osteotomy increases lateral hinge resistance to fracture

PURPOSE

It was hypothesized in this in-vitro study that positioning a K-wire intersecting the cutting plane at the theoretical lateral hinge location would limit the cut depth and help preserve the lateral hinge during the opening of the osteotomy. Objectives were (1) to compare the mechanical resistance of the hinge and the protective effect of leaving the K-wire during the opening procedure (2) to check if the K-wire would limit the depth of the osteotomy.

METHODS

An ex-vivo mechanical study, testing 5 pairs of fresh-frozen tibias, was designed. CT-scan based Patient-specific cutting guides were obtained to define the cutting plane and the location of the K-wire at the hinge, using standardized 3D planning protocol. In each pair, OWHTO was performed either with or without the K-wire. To evaluate the hinge's resistance to fracture, the specimens were rigidly fixed at the proximal tibia and a direct load was applied on the free tibial diaphysis to open the osteotomy. The maximum load at breakage, maximum permissible displacement and maximal angulation of the osteotomy before hinge failure was measured. To assess the preservation of an unscathed hinge (protected by the K-wire), the distance from the end of the osteotomy cut to the lateral tibial cortical was measured in mm.

RESULTS

The maximum load to hinge breakage in the K-wires PsCG knees compared to the control group (48.3 N vs 5.5 N, p = 0.004), the maximum permissible displacement (19.8 mm vs 7.5 mm, p = 0.005) and the maximal angulation of the osteotomy before hinge breakage (9.9° vs 2.9°, p = 0.002) were all statistically superior in the K-wires PsCG knees compared to the control group. A mean distance of 10 ± 1 mm between cut-bone (saw-print) and lateral hinge cortical bone was found post-performing the osteotomy and the hinge failing.

CONCLUSION

The maximum load to breakage and the maximum permissible displacement were, respectively, 880% and 260% higher during the opening of the OWHTO in using K-wires compared to the non-K-wire control group. This confirms the mechanical advantage of using a K-wire for both stabilization and protecting the Hinge during OWHTO. This comparative cadaveric study shows an improvement of the lateral hinges resistance to failing during the opening of the osteotomy. This can be achieved by the placement of a K-wire intersecting the cutting plane at the theoretical location of the lateral hinge.

The Use of Navigation in Osteotomies Around the Knee

Osteotomies around the knee for treating osteoarthritis or knee instability are currently well-established procedures. Success of these realignment procedures is based on the accuracy and the reliability of correction angles in the coronal and sagittal alignment. In this context of improving precision and adapting the correction to each patient, navigation is currently being widely used. The rationale for its use is based on understanding the advantages and limitations, technical principles, and potential pitfalls. This article describes these areas and the overall clinical outcomes of this system for knee osteotomies.

Comparison of navigated and conventional high tibial osteotomy for the treatment of osteoarthritic knees with varus deformity: A meta-analysis

BACKGROUND

High tibial osteotomy (HTO) is a usefully surgical procedure to correct the malalignment and delay the progression of osteoarthritis. It is still controversy whether navigation system can offer more accuracy of targeted alignment and achieve better clinical outcomes than conventional method. The purpose of present meta-analysis was to investigate whether navigation system was superior to conventional method with regard to clinical and radiographic outcomes.

METHOD

The included studies compared the clinical and radiographic outcomes between navigated HTO group and conventional group. The clinical assessments were Lysholm Score, AKS Function Score and Arc of motion, and the radiographic outcomes were Mechanical axis (MA), Weight bearing line ratio (WBL), Outliers of alignment and Change in TPS used to evaluate alignment correction. The meta-analysis was performed using Review Manager 5.3 software. Downs and Black and the Newcastle-Ottawa Scale (NOS) were used to evaluate the study quality.

RESULT

Sixteen studies were eligible in present meta-analysis, including thirteen studies concerning opening wedge HTO and three studies involving closing wedge HTO. Clinical outcomes were only reported in studies which used opening wedge HTO. No significant differences were observed in all clinical outcomes between navigated and conventional HTO. Regarding radiographic outcomes, no significant difference in WBL ratio was observed between navigated and conventional HTO. Patients undergoing navigated HTO were associated with significantly greater in MA and lower in Outliers of alignment compared with those undergoing conventional HTO. Compared with conventional HTO, increase in TPS was significantly lower in navigated HTO group using opening wedge HTO, but decrease in TPS was significantly greater in navigated HTO group using closing wedge HTO.

CONCLUSION

Our meta-analysis demonstrated that navigated HTO offered more accuracy and precision of alignment correction, except WBL ratio. However, better clinical outcomes were not observed in navigation group.

Serial Changes in the Joint Space Width and Joint Line Convergence Angle After Closed-Wedge High Tibial Osteotomy

BACKGROUND

There have been little data concerning serial changes in the joint space width (JSW) and joint line convergence angle over the course of follow-up periods after closed-wedge high tibial osteotomy (CWHTO).

PURPOSE

To evaluate serial changes in the JSW and joint line convergence angle after CWHTO.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 100 computer-assisted CWHTOs with a minimum follow-up period of 3 years (mean, 4.4 years) were analyzed. Clinically, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score was evaluated. Radiographically, the mechanical axis was measured preoperatively and postoperatively. The minimal JSW was measured as the shortest distance between the femur and the tibia. The convergence angle was measured as the angle between the tangent to the subchondral plates of the femoral condyle and the tibial plateau. Serial changes in these measurements were analyzed preoperatively; at 3 months, 6 months, 1 year, and 2 years postoperatively; and at the final follow-up. The intraclass correlation coefficients for all measurements were greater than 0.8.

RESULTS

The mean WOMAC score improved from 41.4 preoperatively to 14.9 at the final follow-up. The preoperative and postoperative mean mechanical axis was 8.1° varus and 1.6° valgus, respectively. The mean minimal JSW was 2.5, 2.9, 2.9, 3.1, 3.2, and 3.1 mm preoperatively and at 3 months, 6 months, 1 year, 2 years, and the final follow-up, respectively ( P < .001). The mean convergence angle was 4.4°, 3.9°, 4.0°, 4.1°, 4.2°, and 4.3°, respectively, during the same time periods ( P = .068).

CONCLUSION

Cartilage healing, as indicated by the JSW, and clinical improvement were maintained over the minimum 3-year follow-up after CWHTO. Cartilage pressure, as indicated by the convergence angle, remained unchanged after CWHTO.

Outcome reporting following navigated high tibial osteotomy of the knee: a systematic review

PURPOSE

This systematic review evaluates radiographic and clinical outcome reporting following navigated high tibial osteotomy (HTO). Conventional HTO was used as a control to compare outcomes and furthermore investigate the quality of evidence in studies reporting outcomes for navigated HTO. It was hypothesized that navigated HTO will show superior clinical and radiographic outcomes compared to conventional HTO.

METHODS

Two independent reviewers searched PubMed, Ovid (MEDLINE), EMBASE, and Cochrane databases for studies reporting outcomes following navigated HTO. Titles, abstracts, and full-text were screened in duplicate using an a priori inclusion and exclusion criteria. Descriptive statistics were calculated using Minitab ^® statistical software. Methodological Index for Nonrandomized Studies (MINORS) and Cochrane Risk of Bias Scores were used to evaluate methodological quality.

RESULTS

Thirty-four studies which involved 2216 HTOs were analysed in this review, 1608 (72.6 %) navigated HTOs and 608 (27.4 %) conventional HTOs. The majority of studies were of level IV evidence (16). Clinical outcomes were reported in knee and function scores or range of motion comparisons. Postoperative clinical and functional scores were improved by navigated HTO although it is not demonstrated if there is significant improvement compared to conventional HTO. Most common clinical outcome score reported was Lysholm scores (6) which report postoperative scores of 87.8 (standard deviation 5.9) and 88.8 (standard deviation 5.9) for conventional and navigation-assisted HTO, respectively. Radiographic outcomes reported commonly were weight-bearing mechanical axis, coronal plane angle, and posterior tibial slope angle in the sagittal plane. Studies have shown HTO gives significant correction of mechanical alignment and navigated HTO produces significantly less change in posterior tibial slope postoperatively compared to conventional. The mean MINORS for the 17 non-comparative studies was 9/16, and 15/24 for the 14 non-randomized comparative studies.

CONCLUSION

Navigation HTO results in improved mechanical axis alignment and demonstrates significantly better control over the tibial slope angle change postoperatively compared to conventional methods; however, these improvements have not yet been reflected in clinical outcome scores. Overall the studies report HTO does create significantly improved knee scores and functions compared to patients' preoperative ratings regardless of technique. Future studies on HTO outcomes need to focus on consistency of outcome reporting.

LEVEL OF EVIDENCE

IV.