The complications of high tibial osteotomy: closing- versus opening-wedge methods

Infection in osteotomy around the knee: Incidence, management and outcomes in a high-volume case series

PURPOSE

Current evidence around the management of osteotomy-related infection is insufficient to robustly underpin the expert statements formulated by a recent European consensus statement. We present a review of a large case series in a high-volume osteotomy practice to contribute to the understanding of the incidence, management and outcome of infection in this subspecialty area.

METHODS

Analyses of two prospectively collected databases for all osteotomy around the knee and infections related to osteotomy were performed, along with a review of hospital readmission data to capture all osteotomy-related infections. Clinical notes were reviewed to assess patient demographics, incidence of infection, how infection was managed and clinical outcome.

RESULTS

In a series of 822 osteotomies in 755 patients, there were 21 (2.8%) cases of suspected infection. Twelve (1.6%) were contemporaneously deemed 'superficial' and nine confirmed 'deep' infections (1.2%). Deep infections were all successfully managed with wound debridement, with or without plate removal, depending on union and time from initial surgery. One of these infections was noted during a revision procedure, but no revision was carried out as a direct result of infection, no external fixation was required and no infected nonunions were experienced.

CONCLUSION

All of the cases in this series were managed successfully with debridement ± removal of the plate, without the need for revision or external fixation. Any potential signs of infection around an osteotomy, especially in the case of medial high tibial osteotomy, should raise awareness for deep infection and the need for further surgery due to the limited overlying soft tissue cover. This evidence supports the recent European Society of Sports Traumatology, Knee Surgery and Arthroscopy algorithm.

LEVEL OF EVIDENCE

Level IV, case series.

Comparative analysis of gait: Similar coronal but different sagittal effects between closing-wedge and opening-wedge high tibial osteotomy

BACKGROUND

High tibial osteotomy is an established surgical option for medial compartment osteoarthritis of the knee with varus alignment. It can be divided into open wedge and closing wedge by operative technique. Although they have fundamental differences, little is known about the biomechanical consequences of the two surgical methods.

METHODS

Thirty-eight patients with medial compartment osteoarthritis who underwent high tibial osteotomy (19 open-wedge and 19 closing-wedge) were retrospectively reviewed. Clinical scores and radiological measurements were assessed until postoperative two years. Gait analysis was performed preoperatively and again at postoperative one year.

FINDINGS

Varus alignment was corrected in both groups without a significant difference between them (p = 0.543). However, posterior tibial slope was higher, and the Blackburne-Peel ratio was lower in the open wedge osteotomy group after surgery (both p < 0.001). Reduction of dynamic knee varus and knee adduction moment were observed in both groups without significant differences. However, after surgery, average knee range of motion (63.3° vs 57.3°, p < 0.001) and the magnitude of knee flexion moment was significantly lower (p = 0.005) in the closing wedge group. There were no significant differences in the Kujala Anterior Knee Pain Scale and the occurrence of patellofemoral arthritis between the groups postoperatively.

INTERPRETATION

After osteotomy, a smaller average knee range of motion in the sagittal plane and a higher knee flexion moment were observed in the open wedge osteotomy group, suggesting quadriceps muscle avoidance. However, no differences in clinical scores or the short-term occurrence of patellofemoral arthritis were noted between the two surgical techniques.

Comparison of short-term clinical outcomes between open-wedge high tibial osteotomy and tibial condylar valgus osteotomy

BACKGROUND

This study aimed to compare radiological features and short-term clinical outcomes between open-wedge high tibial osteotomy (OWHTO) and tibial condylar valgus osteotomy (TCVO), to provide information facilitating decision-making regarding those two procedures.

METHODS

Twenty-seven cases involving 30 knees that had undergone OWHTO (HTO group) and eighteen cases involving 19 knees that had undergone TCVO (TCVO group) for medial compartment knee osteoarthritis (OA) were retrospectively evaluated. Patient characteristics, severity of knee OA, lower limb alignment, joint congruity and instability were measured from standing full-length leg and knee radiographs obtained before and 1 year after surgery. Range of motion in the knee joint was measured and Knee Injury and Osteoarthritis Outcome Score (KOOS) was obtained to evaluate clinical results preoperatively and 1 year postoperatively.

RESULTS

Mean age was significantly higher in the TCVO group than in the HTO group. Radiological features in the TCVO group included greater frequencies of advanced knee OA, varus lower limb malalignment, higher joint line convergence angle, and varus-valgus joint instability compared to the HTO group before surgery. However, alignment of the lower limb and joint instability improved to comparable levels after surgery in both groups. Maximum flexion angles were significantly lower in the TCVO group than in the HTO group both pre- and postoperatively. Mean values in all KOOS subscales recovered similarly after surgery in both groups, although postoperative scores on three subscales (Symptom, Pain, and ADL) were lower in the TCVO group (Symptom: HTO, 79.0; TCVO, 67.5; Pain: HTO, 80.5; TCVO, 71.1; ADL: HTO, 86.9; TCVO, 78.0).

CONCLUSIONS

Both osteotomy procedures improved short-term clinical outcomes postoperatively. TCVO appears preferable in cases of advanced knee OA with incongruity and high varus-valgus joint instability. An appropriate choice of osteotomy procedure is important to obtain favorable clinical outcomes.

Effect of hardware removal and second-look arthroscopy after open-wedge high tibial osteotomy

INTRODUCTION

Open-wedge high tibial osteotomy (OWHTO) is the standard and safe procedure for medial compartment osteoarthritis. Although hardware removal (HWR) is performed after post-OWHTO bone union, the effects of HWR on OWHTO have been rarely reported. We hypothesised that HWR would improve range of motion (ROM) and implant-related complications. Thus, this study aimed to investigate the effects of HWR on postoperative ROM, the Japan Orthopaedic Association (JOA) score/visual analogue scale (VAS) score and hardware-related complications after OWHTO.

METHODS

Patients who underwent OWHTO between January 2016 and June 2018 and HWR were retrospectively reviewed. To perform OWHTO, locking plates and prosthetic bone were used to achieve optimal stabilisation of biplanar osteotomy. HWR was performed after a second-look arthroscopy through the previous skin incision. For clinical evaluation, the JOA score, VAS score, and ROM were assessed before and 1 year after HWR using the Wilcoxon rank test. Logistic regression analysis was performed to identify the predictors of post-HWR improvement.

RESULTS

Of 98 knees examined (91 patients), 80 (73 patients; 39 men and 34 women) were included. At the time of OWHTO, mean age was 64.0 ± 9.7 years and body mass index, 25.5 ± 3.1 kg/m2; Kellgren-Lawrence (KL) grade 1 was seen in 20 cases, KL-2 in 46, and KL-3 in 14. Mean periods between OWHTO and HWR were 13.4 ± 2.0 months, and 11.9 ± 1.2 months between HWR and evaluation. The JOA score and flexion angle significantly improved after HWR (The JOA score: p = 0.026 flexion angle: p < 0.001); however, the VAS score and extension angle did not (VAS score: p = 0.162, extension angle: p = 0.934). Hardware irritation was observed in four cases (5%), which improved after HWR. Logistic regression analysis revealed that lower preoperative KL grade and flexion angle were predictors of improvement after HWR [KL grade: p = 0.008; odds ratio 3.244, 95% confidence interval (CI) 1.350-7.794; flexion angle: p < 0.001; odds ratio 1.150, 95% CI 1.062-1.245].

CONCLUSION

HWR improves flexion angle, clinical outcomes and hardware-related complications after OWHTO. Preoperative KL grade and flexion angle are predictors of improvement after HWR in patients who have undergone OWHTO.

Incidence of Complications and Revision Surgery After High Tibial Osteotomy: A Systematic Review

BACKGROUND

High tibial osteotomy (HTO) is a well-recognized procedure for its effectiveness in treating symptomatic early knee arthritis and malalignment. Although there are numerous systematic reviews evaluating the management and outcomes after HTO, there are few investigations on complications of this procedure.

PURPOSE

To systematically review the literature to determine the incidence of intraoperative and postoperative complications associated with medial opening wedge and lateral closing wedge HTOs.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

The Cochrane Database of Systematic Reviews, PubMed, Embase, and MEDLINE databases were queried for studies reporting complications associated with HTO with or without concomitant procedures. Data including patient characteristics, procedure type, concomitant procedures, follow-up time, and postoperative imaging were extracted. Rates of intra- and postoperative complications, reoperations, and conversion to arthroplasty were recorded.

RESULTS

A total of 71 studies were included for analysis, comprising 7836 patients. The overall intraoperative complication rate during HTO was 5.5% (range, 0%-29.3%), and the overall postoperative complication rate was 6.9% (range, 0%-26.6%). The most common intraoperative complication was lateral hinge fracture (incidence, 9.1%; range, 0%-30.4%) in medially based HTOs and peroneal nerve injury in laterally based HTOs (incidence, 3.2%; range, 0%-8.7%). The overall incidence of neurovascular injury after medially or laterally based HTOs was 1.1% (range, 0%-18.9%). The most common postoperative complication was superficial infection (incidence, 2.2%; range, 0%-13%). Of the included studies, 62 included postoperative radiographic analysis, and among those, the incidence of nonunion was 1.9% (range, 0%-15.5%), loss of correction was 1.2% (range, 0%-34.3%), and implant failure was 1.0% (range, 0%-10.2%). Among studies reporting revision surgeries, the overall reoperation rate was 15.5% (range, 0%-70.7%), with the most common type of reoperation being hardware removal (incidence, 10.0%; range, 0%-60%).

CONCLUSION

Intraoperatively, medially based HTOs are associated with a 1 in 11 risk of lateral hinge fracture and laterally based HTOs with a 1 in 30 risk of peroneal nerve injury. Postoperative complication rates in the range of 10% to 15% can be expected, including infection (2.9%), loss of correction (1.2%), and nonunion (1.9%). Patients should also be counseled that the reoperation rate is approximately 15%, with hardware removal being the most common procedure.

Use of Preoperative 3D Virtual Planning and 3D-Printed Patient-Specific Guides to Facilitate a Single-Stage Cranial Closing Wedge Ostectomy and Tibial Plateau Leveling Osteotomy Procedure to Address Proximal Tibial Deformity, an Excessive Tibial Plateau Angle, and Cranial Cruciate Ligament Insufficiency in a Dog

A 9-month-old mixed-breed dog was presented for bilateral proximal tibial deformity resulting in an excessive tibial plateau angle and cranial cruciate ligament insufficiency. Initial surgical management of the right pelvic limb was done by performing a cranial closing wedge ostectomy. Inadequate leveling of the plateau resulted in a postliminal meniscal tear which was addressed during a revision tibial plateau leveling osteotomy. The left pelvic limb was managed in a single-session surgery using three-dimensional (3D) virtual surgical planning and custom 3D-printed surgical guides to perform a combined cranial closing wedge ostectomy and tibial plateau leveling osteotomy. Postoperative 3D analysis of the left tibia revealed the accuracy of the surgical result within 2° of the virtual surgical plan. The dog developed a transient grade II/IV left medial patellar luxation following surgery but ultimately attained a full functional recovery and was actively engaged in competitive agility work 46 months following surgery on the left pelvic limb.

Radiologic simulation of leg length change after double level osteotomy in preoperative surgical planning

BACKGROUND

To evaluate the expected postoperative total leg length change using preoperative radiographs during surgical planning of four different methods of double level osteotomy (DLO).

METHODS

This study included 34 patients (44 knees) who underwent DLO for varus knee osteoarthritis. Surgical planning was performed so that the postoperative weight bearing line ratio was 62.5%. In DLO, lateral closed or medial open wedge distal femoral osteotomy (LCWDFO, MOWDFO) was performed so that the postoperative mechanical lateral distal femoral angle was 85°, and residual deformity was corrected with medial open or lateral closed wedge high tibial osteotomy (MOWHTO, LCWHTO). Pre- and surgical planning X-rays in the one-leg standing position were compared to assess the change in leg length, and the factors affecting it, in the various surgical groups. The proportion of cases in which Δ total leg length was greater than 6 mm (symptomatic change) was investigated.

RESULTS

The mean postoperative total leg length increased significantly with LCWDFO + MOWHTO, MOWDFO + MOWHTO, and MOWDFO + LCWHTO, while it decreased with LCWDFO + LCWHTO. The proportion of cases with a postoperative total leg length change > 6 mm was 72.7%, 2.3%, 100%, and 6.8% in LCWDFO + MOWHTO, LCWDFO + LCWHTO, MOWDFO + MOWHTO, and MOWDFO + LCWHTO, respectively. In addition, the preoperative hip-knee-ankle angle correlated negatively with the postoperative total leg length change in LCWDFO + MOWHTO, MOWDFO + MOWHTO, and MOWDFO + LCWHTO, but not in LCWDFO + LCWHTO.

CONCLUSIONS

MOWDFO + MOWHTO had the largest postoperative leg length change and MOWDFO + LCWHTO had the smallest. Symptomatic leg length change (> 6 mm) should be considered in MOWDFO + MOWHTO and LCWDFO + MOWHTO.

Incidence and risk factors for surgical site infection after medial opening-wedge high tibial osteotomy using a locking T-shape plate

Medial opening-wedge high tibial osteotomy (MOWHTO) is a well-established surgical method for treatment of isolated medial compartment osteoarthritis with varus deformity, but the surgical outcomes may be compromised by surgical site infection (SSI). This study aimed to investigate the incidence and the risk factors for SSI after MOWHTO. This retrospective study included consecutive patients who underwent MOWHTO for isolated medial compartment osteoarthritis with varus deformity in two tertiary referral hospitals from January 2019 and June 2021. Patients who developed SSI within 12 months of surgery were identified by inquiring the medical records for index hospitalisation, notes of after-discharge outpatient visits, or records of readmission for treatment of SSI. Univariate comparisons were performed to detect the differences between SSI and non-SSI groups, and multivariate logistic regression analysis was used to identify the independent risk factors. Six hundred sixteen patients with 708 procedures were included and 30 (4.2%) cases of SSI occurred, with 0.6% rate for deep SSI and 3.6% for superficial. Univariate analyses showed significant difference between groups in terms of morbidity obesity (≥32 kg/m2 ) (20.0% vs 8.9%), comorbid diabetes (26.7% vs 11.1%), active smoking (20.0% vs 6.3%), time from admission to operation (5.2 ± 4.0 vs 4.1 ± 3.0), size of osteotomy ≥12 mm (40.0% vs 20.0%), type of bone grafting and lymphocyte count (2.1 ± 0.5 vs 1.9 ± 0.6). However, in the multivariate analysis, only active smoking (OR, 3.4; 95% CI, 1.4-10.2), size of osteotomy ≥12 mm (OR, 2.8; 95% CI, 1.3-5.9) and allogeneic/artificial vs no bone grafting (OR, 2.4; 95% CI, 1.0-10.8) remained significant. SSI was not uncommon after MOWHTO, but the majority was superficial. The identified three independent factors, including smoking, size of osteotomy ≥12 mm and allogeneic/artificial bone grafting would help risk assessment and stratification, target risk factor modification and clinical surveillance, and inform patient counselling.

Opening-Wedge High Tibial Osteotomy With High Hinge Position Risks Lateral Hinge Fracture in Men With Posterolateral Tibial Condyle Protrusion

PURPOSE

The primary aim of this study was to evaluate the 3-dimensional morphology of the proximal tibia around the osteotomy plane in open-wedge high tibial osteotomy, focusing on the posterolateral (PL) and posteromedial (PM) tibial condyles, and to clarify the changes in morphologic parameters due to differences in patient characteristics and hinge position. The secondary aim was to examine whether morphologic features were associated with insufficient osteotomy, which increases the risk of lateral hinge fracture (LHF).

METHODS

The PL and PM anteroposterior distance, asymmetry ratio, and discrepancy between PL and PM distances along the tibial osteotomy plane were measured. We investigated changes in the parameters due to differences in patient characteristics and hinge position. Osteotomy configurations and LHFs were evaluated using postoperative computed tomography scans.

RESULTS

The 3-dimensional preoperative plans of 117 knees (male, 41 knees; female, 76 knees) were evaluated. PL distances were larger than PM distances in almost all cases. The average asymmetry ratio was 1.35, and the standard deviation was 0.22. Higher hinge position was associated with a larger asymmetry ratio and discrepancy (P < .001). The asymmetry ratio and discrepancy were independently positively correlated with male sex (P = .002 and P = .001, respectively) and gentle posterior tibial slope (P < .001 and P < .001, respectively). Osteotomies with type III LHFs showed lower osteotomy sufficiency than osteotomies without LHFs (P < .001).

CONCLUSIONS

PL tibial condyle protrusion was more pronounced in male patients and those with a high hinge position, and may result in insufficient PL osteotomy, which is a risk factor for type III LHF during open-wedge high tibial osteotomy. The optimal hinge position was located approximately 15 mm and 20 mm distal to the lateral tibial plateau in female and male patients, respectively.

LEVEL OF EVIDENCE

IV: retrospective case series.

Higher activity level after opening wedge high tibial osteotomy compared to medial unicompartimental knee arthroplasty in a selected cohort of advanced age: A propensity score-matched analysis

BACKGROUND

High tibial osteotomy (HTO) and medial unicompartmental knee arthroplasty (mUKA) are accepted treatment for medial knee osteoarthritis (OA). Patients often present meeting indications for both procedures. The purpose of this study was to compare results after MOWHTO and UKA in a matched population of patients older than 50 years.

METHOD

A retrospective analysis searching for patients older than 50 years meeting indication both for UKA and MOWHTO was performed. A propensity score matching (PSM) based on demographics and clinical data was performed. Tegner activity scale (TAS), Lysholm knee score (LKS) and numeric rating scale for pain (NRS) were recorded prospectively prior to surgery, at 6 months and after a minimum of 4 years.

RESULTS

64 UKA and 71 MOWHTO were found. Mean follow up was similar (54,05 ± 4,80 and 52,62 ± 3,91). A significant improvement was found in both groups for all outcomes at 6 months and at final follow up. PSM yielded 29 pairs. Patients treated with MOWHTO showed superior TAS scores at 6 months (3,41 ± 0,50 vs 3,10 ± 0,56; p < 0,05) and at final follow up (3,83 ± 0,80 vs 3,27 ± 0,59; p < 0,005). NRS and LKS were comparable between groups.

CONCLUSIONS

MOWHTO performed using an open wedge technique, with locking plate and a fast rehabilitation protocol guaranteed higher level of activity than UKA in patients older than 50 years. Difference is significant already at 6 months and last longer than 4 years.

LEVEL OF EVIDENCE

III.

Complications after high tibial osteotomy and distal femoral osteotomy are associated with increasing medical comorbidities and tobacco use

PURPOSE

The purpose of this study was to assess complications, reoperations, and their risk factors at 90 days and 2 years after high tibial osteotomy (HTO) and distal femoral osteotomy (DFO) in a national cohort.

METHODS

The PearlDiver Mariner Dataset was queried using International Classification of Diseases (ICD) and Current Procedural Terminology (CPT) codes for HTO and DFO, complications, and subsequent surgery. Minimum follow-up was 2 years and complications were assessed at 90 days and 2 years. Hospital readmission in the first 90 days was also assessed. Univariate and multiple logistic regression were utilized to identify risk factors for complications and re-operation.

RESULTS

The 90-day and 2-year complication rates after HTO (n = 1780) were 11.6% and 31.7%, compared to 21.5% (p < 0.0001) and 41.5% (p = 0.0001) after DFO (n = 446). Infection was the most frequent early (90-day) complication for both HTO and DFO cohorts, while hardware problems were most common at 2 years. Increasing Elixhauser Comorbidity Index (ECI) was associated with increased odds of infection, readmission, and hardware-associated complications in both cohorts. Gender and tobacco use were also associated with various complications after HTO. At 2 years, 23.7% of HTO patients and 26.2% of DFO patients had undergone subsequent surgery. Hardware removal occurred in 16.4% of HTO and 18.4% of DFO patients (n.s.), while 4.5% of HTO and 5.2% of DFO patients underwent total knee arthroplasty (TKA) within 2 years (n.s.).

CONCLUSION

HTO and DFO have substantial complication rates in the short and mid term, with a higher rate of overall complications observed after DFO as compared to the HTO cohort. After both procedures, roughly one quarter of patients will undergo subsequent surgery within 2 years. Patients with tobacco use and numerous medical co-morbidities may not be optimal candidates due to increased complication rates. Elixhauser Comorbidity Index (ECI) may be an useful tool for risk assessment prior to surgery.

LEVEL OF EVIDENCE

Retrospective cohort study, III.

Less risk of conversion to total knee arthroplasty without significant clinical and survivorship difference for opening-wedge high tibial osteotomies in varus knee deformities at 10-year minimum follow-up compared to closing-wedge high tibial osteotomies

PURPOSE

The purpose of this study was to evaluate the clinical outcomes and survivorship at minimum 10-year follow-up of patients undergoing primary valgisation high tibial osteotomy (HTO) for medial osteoarthritis (OA), treated by Opening-Wedge HTO (OW-HTO) or Closing-Wedge HTO (CW-HTO).

METHODS

This was a retrospective cohort study of consecutive patients presenting to a single institution undergoing HTO for isolated medial compartment OA. Two hundred and twenty three HTOs for isolated medial tibio-femoral OA were performed between January 2002 and December 2010. Patients were eligible if they had minimum 10-year follow-up and received either a CW or OW-HTO. Fifteen (6.7%) patients died and twenty-five (11.2%) were lost to follow-up. One hundred and eighty three (82.1%) patients were included in the final analysis and divided into two groups: OW-HTO (96/183; 52.4%) and CW-HTO (87/183; 47.6%). Range of motion, KSS, KOOS scores, and conversion to TKA rate were analyzed between groups. Both groups were comparable regarding age, arthrosis stage, gender, ASA score and BMI at the time of HTO. Survival analysis was conducted with re-intervention for TKA as the end point.

RESULTS

At the time of HTO, mean age was 55 years ± 7.9 (27-73.9) with 72.7% of patients being male. The mean follow-up was 13.3 years ± 2.7 (10-19). Sixty-four (34.9%) patients underwent TKA at a mean delay of 9.3 years ± 3 (3-16). The conversion to TKA rate was significantly higher in the CW-HTO group versus the OW-HTO group: 42.5% (37/87) versus 28.1% (27/96) (p = 0.04). The survival at 15-year follow-up was 59.2% in the OW-HTO group versus 54.6% in the CW-HTO group (n.s.). At 13-year follow-up, KSS Function score was significantly better in the OW-HTO (90.9 versus 82.4; p = 0.007). No significant difference was observed between the two groups regarding the KOOS score, KSS Knee Score and complication rate.

CONCLUSION

At mean follow-up of 13 years, no significant clinical and survivorship difference was observed between the two groups. The conversion to TKA was significantly lower following OW-HTO. Minor correction was associated with risk of requiring subsequent TKA.

LEVEL OF EVIDENCE

Retrospective case series, IV.

Knee Osteotomies Can Be Performed Safely In An Ambulatory Setting

Purpose

The purpose of this study was to assess the rate of hospital admissions, inpatient conversions, reoperations, and complications associated with tibial tubercle osteotomies (TTO), high tibial osteotomies (HTO), and distal femoral osteotomies (DFO) performed at our ambulatory surgery center compared with our inpatient hospital facility.

Methods

A retrospective review of patients receiving a TTO, HTO or DFO at our institution between June 2011 and October 2019 was performed. Inclusion criteria consisted of patients undergoing the aforementioned procedures for malalignment, and a minimum of 90-days follow-up. Revision osteotomies, those undergoing an osteotomy for an acute fracture, and those with rule-out criteria for outpatient surgery (ASA > 3, and body mass index >40) were excluded. Complications, including readmission and reoperation, were compared between the two groups using either the Fisher’s exact test and independent samples t-test, where applicable, and a P value of <0.05 was considered to be statistically significant.

Results

The study included 531 patients undergoing osteotomies (222 ambulatory surgical center [ASC] and 309 hospital) with no patients lost to follow-up in the 90-day postoperative period. No patients operated on at an ASC required transfer to inpatient setting. There were no differences in complication rates, readmission, or reoperation rates among the two groups (4.1% vs 4.9%; P = .8328; 3.1% vs 4.5%, P = .5026; 3.1% vs 4.5%; P = .5026; respectively). Complications, including surgical site infection and arthrofibrosis were not significantly different in the two cohorts, (1.4% vs. 2.6%, P = .341 and 1.4% vs 1%; P = .698, respectively).

Conclusions

Osteotomies about the knee performed in an ambulatory setting were safe, with no difference in readmission, reoperation, or postoperative complications compared to those performed at an inpatient hospital. Additionally, no patient required conversion from an outpatient to an inpatient setting.

Level of Evidence

Level III, retrospective comparative study.

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.

Surgical planning of osteotomies around the knee differs between preoperative standing and supine radiographs in nearly half of cases

Background

To evaluate the difference in surgical planning of osteotomies around the knee between preoperative standing and supine radiographs and to identify risk factors for discrepancies in surgical planning.

Methods

This study included 117 knees of 100 patients who underwent osteotomies around the knee for knee osteoarthritis with genu varum. Surgical planning was performed so that the target point of the postoperative weight-bearing line (WBL) ratio was 62.5% in preoperative standing and supine radiographs. If the opening gap would be > 13 mm in open-wedge high tibial osteotomy (OWHTO), closed-wedge HTO (CWHTO) was planned. If the postoperative mMPTA would be > 95° in isolated HTO, double-level osteotomy (DLO) was planned. In DLO, lateral closed-wedge distal femoral osteotomy was performed so that the postoperative mechanical lateral distal femoral angle (mLDFA) was 85°, and any residual varus deformity was corrected with HTO.

Results

Surgical planning differed between standing and supine radiographs in 43.6% of cases. In all knees for which surgical planning differed between standing and supine radiographs, a more invasive type of osteotomy was suggested by standing radiographs than by supine radiographs. The risk factors for discrepancies in surgical planning were a lower WBL ratio in standing radiographs and a lower joint line convergence angle in supine radiographs.

Conclusions

Surgical planning of DLO, CWHTO and OWHTO, in standing radiographs differed from that in supine radiographs in nearly half of the cases. Surgical planning based on standing radiographs leads to more invasive surgical procedures compared to supine radiographs.

Predicting knee adduction moment response to gait retraining with minimal clinical data

Knee osteoarthritis is a progressive disease mediated by high joint loads. Foot progression angle modifications that reduce the knee adduction moment (KAM), a surrogate of knee loading, have demonstrated efficacy in alleviating pain and improving function. Although changes to the foot progression angle are overall beneficial, KAM reductions are not consistent across patients. Moreover, customized interventions are time-consuming and require instrumentation not commonly available in the clinic. We present a regression model that uses minimal clinical data—a set of six features easily obtained in the clinic—to predict the extent of first peak KAM reduction after toe-in gait retraining. For such a model to generalize, the training data must be large and variable. Given the lack of large public datasets that contain different gaits for the same patient, we generated this dataset synthetically. Insights learned from a ground-truth dataset with both baseline and toe-in gait trials (N = 12) enabled the creation of a large (N = 138) synthetic dataset for training the predictive model. On a test set of data collected by a separate research group (N = 15), the first peak KAM reduction was predicted with a mean absolute error of 0.134% body weight * height (%BW*HT). This error is smaller than the standard deviation of the first peak KAM during baseline walking averaged across test subjects (0.306%BW*HT). This work demonstrates the feasibility of training predictive models with synthetic data and provides clinicians with a new tool to predict the outcome of patient-specific gait retraining without requiring gait lab instrumentation.

Gait retraining is a conservative intervention for knee osteoarthritis shown to reduce pain and improve function. Although customizing a treatment plan for each patient results in a better therapeutic response, customization cannot yet be performed outside of the gait laboratory, preventing research advances from becoming part of clinical practice. Our work aimed to build a model that accurately predicts whether a patient with knee osteoarthritis will benefit from non-invasive gait retraining using measures that can be easily collected in the clinic. To overcome the lack of large datasets required to train predictive models, we generated data synthetically (N = 138) based on limited ground-truth examples, and we provide experimental evidence for the model’s ability to generalize to real data (N = 15). Our results contribute toward a future in which clinicians can use data collected in the clinic to easily identify patients who would respond to therapeutic gait retraining.

Anterior Slope Correction-Flexion Osteotomy in Traumatic Genu Recurvatum

A decreased posterior tibial slope has been associated with an increased risk of posterior cruciate ligament failure, anterior knee pain, and premature knee osteoarthritis. Trauma is a common cause of osseous genu recurvatum. Surgical management is recommended to correct the tibial slope and prevent knee pain and osteoarthritis progression. This article discusses our preferred treatment using a proximal tibial opening-wedge osteotomy for surgical management of genu recurvatum secondary to significant anterior tibial slope.

The range of the required anterolateral cortex osteotomy distance varied widely in biplanar open wedge high tibial osteotomy

Background

To evaluate the anterolateral cortex distance between the lateral edge of the flange and hinge point in surgical simulations of biplanar open wedge high tibial osteotomy (OWHTO) using computed tomography (CT) images.

Methods

A total of 110 knees treated with OWHTO for medial knee osteoarthritis with varus malalignment were enrolled. Surgical simulations of biplanar OWHTO, including the transverse and ascending cuts, were performed in the standard manner using preoperative CT images. The distance between the lateral edge of the flange and the hinge point was measured. In addition, another plane of the ascending cut was defined through the hinge point. The angle between these two planes of the ascending cut was measured in the axial plane.

Results

The mean anterolateral cortex distance was 9.4 ± 4.6 mm (range, − 1.5 mm – 20.3 mm). In 3 knees, osteotomy of the anterolateral cortex was not needed. The mean value of the angle between the two ascending cut planes was 8.4 ± 3.6° (range, − 2.1° – 14.8°), which meant that osteotomy of anterolateral cortex was not needed when the ascending cut was performed at this angle. Moreover, these two values increased when the flange thickness was changed from one-third to one-fourth of the anteroposterior tibial diameter or the angle between the transverse and ascending cuts was changed from 110° to 120°.

Conclusions

In biplanar OWHTO, anterolateral cortex osteotomy would be required. However, the range of the required anterolateral cortex osteotomy distance varied widely and the required anterolateral cortex osteotomy distance depended on the flange thickness and the angle between the transverse and ascending cuts. In addition, change of the ascending cut plane can change the necessity of anterolateral cortex osteotomy.

Extent of Preoperative Medial Meniscal Extrusion Influences Intermediate-Term Outcomes After Medial Opening-Wedge High Tibial Osteotomy

BACKGROUND

The purpose of the present study was to determine the relationship between preoperative medial meniscal extrusion, as classified according to magnetic resonance imaging (MRI), and medial opening-wedge high tibial osteotomy outcomes at intermediate-term follow-up.

METHODS

We reviewed the records for 212 patients who had undergone medial opening-wedge high tibial osteotomy for the treatment of medial compartment osteoarthritis between January 2009 and September 2014, with a minimum duration of follow-up of 5 years. Patients were divided into 2 groups according to the presence of pathologic medial meniscal extrusion (>3 mm). Moreover, patients were divided into 4 groups according to MRI Osteoarthritis Knee Score (MOAKS) criteria and relative medial meniscal extrusion values. Associations between the extent of preoperative medial meniscal extrusion and clinical outcomes over a mean duration of follow-up of 8.1 years were evaluated with use of Spearman rank correlation analysis. Regression analyses were performed to determine preoperative characteristics relevant to medial meniscal extrusion. Clinical outcomes were assessed with use of the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Tegner activity scale score.

RESULTS

Postoperative KOOS pain scores were significantly different in the pathologic and non-pathologic medial meniscal extrusion groups (69.9 ± 18.0 versus 79.2 ± 11.4, respectively; p < 0.001). Additionally, the degree of preoperative medial meniscal extrusion based on both classification methods and the postoperative KOOS pain score were significantly correlated (r = -0.404 and -0.364; p < 0.001). Despite the inferior clinical outcomes associated with greater preoperative medial meniscal extrusion, medial opening-wedge high tibial osteotomy was associated with significant improvement in all outcome measures between the preoperative and latest follow-up assessments (p < 0.001). Preoperative meniscal patterns, including horizontal flap, complex, and root tears (p = 0.001), and increased Kellgren-Lawrence grade (p < 0.001) were related to the severity of medial meniscal extrusion. The survival rate was 94.8% at a mean of 8.1 years, and survival was not associated with the grade of medial meniscal extrusion as assessed with either classification scheme.

CONCLUSIONS

At intermediate-term follow-up, greater preoperative medial meniscal extrusion was related to inferior postoperative clinical outcomes, specifically pain, after medial opening-wedge high tibial osteotomy. Despite the inferior results associated with preoperative medial meniscal extrusion, medial opening-wedge high tibial osteotomy was associated with a satisfactory survival rate after a mean of 8.1 years, regardless of the extent of medial meniscal extrusion.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Second-look arthroscopic cartilage status is related to intermediate-term outcomes after medial opening-wedge high tibial osteotomy

AIMS

To determine the relationship between articular cartilage status and clinical outcomes after medial opening-wedge high tibial osteotomy (MOHTO) for medial compartmental knee osteoarthritis at intermediate follow-up.

METHODS

We reviewed 155 patients (155 knees) who underwent MOHTO from January 2008 to December 2016 followed by second-look arthroscopy with a mean 5.3-year follow-up (2.0 to 11.7). Arthroscopic findings were assessed according to the International Cartilage Repair Society (ICRS) Cartilage Repair Assessment (CRA) grading system. Patients were divided into two groups based on the presence of normal or nearly normal quality cartilage in the medial femoral condyle: good (second-look arthroscopic) status (ICRS grade I or II; n = 70), and poor (second-look arthroscopic) status (ICRS grade III or IV; n = 85) groups at the time of second-look arthroscopy. Clinical outcomes were assessed using the International Knee Documentation Committee (IKDC) score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and 36-Item Short Form survey.

RESULTS

Significant improvements in all clinical outcome categories were found between the preoperative and second-look arthroscopic assessments in both groups (p < 0.001). At the latest follow-up, the mean IKDC and WOMAC scores in the good status group further improved compared with those at the time of second-look arthroscopic surgery (p < 0.001), which was not shown in the poor status group. The mean IKDC (good status, 72.8 (SD 12.5); poor status, 64.7 (SD 12.1); p = 0.002) and mean WOMAC scores (good status, 15.7 (SD 10.8); poor status, 21.8 (SD 13.6); p = 0.004) significantly differed between both groups at the latest follow-up. Moreover, significant correlations were observed between ICRS CRA grades and IKDC scores (negative correlation; p < 0.001) and WOMAC scores (positive correlation; p < 0.001) at the latest follow-up. Good cartilage status was found more frequently in knees with the desired range of 2° to 6° valgus correction than in those with corrections outside this range (p = 0.019).

CONCLUSION

Second-look arthroscopic cartilage status correlated with clinical outcomes after MOHTO at intermediate-term follow-up, despite the relatively small clinical differences between groups. Cite this article: Bone Joint J 2021;103-B(11):1686-1694.

Salvage of severe knee osteoarthritis: efficacy of tibial condylar valgus osteotomy versus open wedge high tibial osteotomy

INTRODUCTION

To compare the clinical outcomes and the radiographic features between tibial condylar valgus osteotomy (TCVO) and open wedge high tibial osteotomy (OWHTO). New insight into the indication criteria for TCVO was also clarified for achieving satisfactory results.

MATERIALS AND METHODS

Sixty-three knees with medial-compartment osteoarthritis were retrospectively studied. Thirty-four knees with subluxated lateral joint and depression of the medial tibial plateau underwent TCVO and the rest underwent OWHTO. Among the 63 knees included, 27 knees with a pre-operative femorotibial angle (FTA) ≥ 185° were defined as severe varus (subgroup S, 15 in S_TCVO group and 12 in S_HTO group). Lower limb alignment, intra-, and extra-articular congruency were evaluated according to the radiograph obtained before and 24 months after surgery. The visual analog scale (VAS) score and Hospital for Special Surgery (HSS) score were obtained to assess the clinical results. Opening angle and distance of the opening gap in each group were measured by intra-operative fluoroscopy.

RESULTS

During the 2-year follow-up period, the mean HSS score increased from 70.3 to 81.4 in HTO group and 65.9 to 87.3 in TCVO group (p < 0.05). The mean VAS score decreased from 5.9 to 2.6 and 6.0 to 2.1, respectively (p < 0.01). Pre-operative FTA was restored to 172.9° in HTO group and 171.3° in TCVO group, and percentage of mechanical axis (%MA) was improved to 59.7% and 61.2%, respectively. Joint line convergence angle (JLCA) was slightly restored and medial tibial plateau depression (MTPD) was relatively the same before and after OWHTO, while these parameters improved greatly (from 6.4° to 1.2° and - 8.0° to 5.9°, p < 0.01) in TCVO group. More undercorrected knees were observed in S_HTO group than S_TCVO group (58.3% and 13.3%, p < 0.05). Opening angle and distance of the opening gap were larger in TCVO group (19.1° and 14.0 mm) than those in OWHTO group (9.3° and 10.1 mm, p < 0.05).

CONCLUSION

Compared to OWHTO, TCVO had priority in treating advanced knee OA with intra-articular deformity. However, TCVO had a limited capacity to correct the varus angle. Besides, TCVO might be suitable for medial-compartment OA with a pre-operative FTA ≥ 185°.

Personalised high tibial osteotomy has mechanical safety equivalent to generic device in a case-control in silico clinical trial

Background

Despite favourable outcomes relatively few surgeons offer high tibial osteotomy (HTO) as a treatment option for early knee osteoarthritis, mainly due to the difficulty of achieving planned correction and reported soft tissue irritation around the plate used to stablise the osteotomy. To compare the mechanical safety of a new personalised 3D printed high tibial osteotomy (HTO) device, created to overcome these issues, with an existing generic device, a case-control in silico virtual clinical trial was conducted.

Methods

Twenty-eight knee osteoarthritis patients underwent computed tomography (CT) scanning to create a virtual cohort; the cohort was duplicated to form two arms, Generic and Personalised, on which virtual HTO was performed. Finite element analysis was performed to calculate the stresses in the plates arising from simulated physiological activities at three healing stages. The odds ratio indicative of the relative risk of fatigue failure of the HTO plates between the personalised and generic arms was obtained from a multi-level logistic model.

Results

Here we show, at 12 weeks post-surgery, the odds ratio indicative of the relative risk of fatigue failure was 0.14 (95%CI 0.01 to 2.73, p = 0.20).

Conclusions

This novel (to the best of our knowledge) in silico trial, comparing the mechanical safety of a new personalised 3D printed high tibial osteotomy device with an existing generic device, shows that there is no increased risk of failure for the new personalised design compared to the existing generic commonly used device. Personalised high tibial osteotomy can overcome the main technical barriers for this type of surgery, our findings support the case for using this technology for treating early knee osteoarthritis.

Change in leg length after open-wedge high tibial osteotomy can be predicted from the opening width: A three-dimensional analysis

BACKGROUND

The purpose of this study was to evaluate true change in leg length after open-wedge high tibial osteotomy (OWHTO) using three-dimensional (3D) assessments, examine the factors that influence leg lengthening and verify their validity in clinical practice.

METHODS

Study 1: a retrospective case series simulation study, included 46 patients (55 knees) that underwent knee arthroplasty or HTO. OWHTO was simulated from preoperative computed tomography using 3D preoperative planning software. Uni- and multivariate regression analyses were conducted to identify predictors related to change in leg length. Study 2: a retrospective case series study, included 53 patients (55 knees) that underwent OWHTO in another institution. Change in leg length was measured preoperatively and 1 year postoperatively and was compared with the predicted change in leg length calculated using the formula obtained from Study 1.

RESULTS

Study 1: the true change in leg length significantly increased and showed a strong correlation with the opening width. The change in leg length was predicted using the formula "change in leg length = opening width × 0.75-1.5." Study 2: the predicted change in leg length showed no significant difference from the change in leg length 1 year postoperatively and a strong correlation with the measured change.

CONCLUSIONS

The true change in leg length after OWHTO was predicted using the formula obtained from the 3D model. Predicting the change in leg length preoperatively can be a basis to consider other HTOs.

Comparison of Long-Term Survival Analysis Between Open-Wedge High Tibial Osteotomy and Unicompartmental Knee Arthroplasty

BACKGROUND

To compare unicompartmental knee arthroplasty (UKA) and open-wedge high tibial osteotomy (OWHTO) in a long-term follow-up propensity score matching analysis.

METHODS

Patients who underwent UKA or OWHTO for unilateral medial unicompartmental osteoarthritis (OA) between 2004 and 2010 were included. The ROM, HSS score, KS score, WOMAC score, forgotten joint score, OA progression in patellofemoral and lateral compartments, and survivorship were compared within ten years of follow-up between 67 UKA and 67 OWHTO patients after propensity score matching for age, gender, body mass index, range of motion, and osteoarthritis (OA) grade.

RESULTS

At the last follow-up, there were no significant differences between the two groups in clinical outcomes, but the WOMAC score showed better results after UKA (13.1 in UKA vs 18.9 in OWHTO, P = .011). The OA progression also showed no significant difference between the two groups. After a 10-year follow-up, the survival rate was higher in UKA patients (96.2%) than in OWHTO patients (87.7%), with no statistical difference (P = .06).

CONCLUSION

UKA showed better clinical outcomes and OA progressions than OWHTO. The survival rate presented a superiority of 8.5% for the UKA group in the 10-year follow-up, without significant difference.

Application of external osteosynthesis in correction of varus deformation of lower extremities in patients with gonarthrosis

Background. Arthrosis of the knee joint is one of the most common diseases in elderly patients with the varus deformity. One of the treatment methods is corrective osteotomy. Aims: optimization of the diagnosis of deformities in patients with gonarthrosis, improvement of the technique of operation and postoperative control of the main reference lines and angles, assessment of the correction results, analysis of complications. Methods. A retrospective clinical study was conducted. 39 patients were observed, in whom 78 operations were performed on both legs simultaneously. In all the cases, tibia osteotomies and osteosynthesis with the Ilizarov apparatus were used. All the patients underwent an X-ray study of the legs along the entire length with the identification of the main reference lines and angles. Results. In all the cases, it was possible to normalize the position of the mechanical axis and the angle of orientation of the knee joint. After the surgery, the wounds were not sutured to prevent compartment syndrome. The correction was performed in a single-stage manner in elderly patients, gradually in young patients. The period of fixation with the Ilizarov apparatus was 16.6 3.1 weeks. Conclusions. The Ilizarov method has significant advantages: low invasiveness, stable fixation, absence of foreign bodies to the end of treatment. This allows us to recommend it for a wider use in patients with gonarthrosis and varus deformity.

Medial Opening Wedge High Tibial Osteotomy in Knee Osteoarthritis—A Biomechanical Approach

This paper provides an analysis from a biomechanical perspective of the medial opening wedge high tibial osteotomy surgery, a medical procedure commonly used in treating knee osteoarthritis. The aim of this research is to improve the analysed surgical strategy by establishing optimal values for several very important parameters for the geometric planning of this type of surgical intervention. The research methods used are numerical and experimental. We used finite element, a numerical method used to study the intraoperative behavior of the CORA area for different positions of the initiation point of the cut of the osteotomy plane and for different correction angles. We also used an experimental method in order to determine the maximum force which causes the occurrence of cracks or microcracks in the CORA area. This helped us to determine the stresses, the maximum forces, and the force-displacement variations in the hinge area, elements that allowed us to identify the optimal geometric parameters for planning the surgery.

The Influence of Preoperative Tibial Bone Marrow Edema on Outcomes After Medial Opening-Wedge High Tibial Osteotomy

BACKGROUND

The relationship between preoperative subchondral bone marrow edema (BME) in the osteoarthritic knee and pain has been established. However, little is known about the influence of preoperative BME on outcomes after medial opening-wedge high tibial osteotomy (MOHTO). The purpose of this study was to clarify the association between preoperative BME severity and clinical outcomes after MOHTO at intermediate follow-up.

METHODS

We reviewed the cases of 105 consecutive patients who underwent MOHTO for osteoarthritis of the knee with preoperative subchondral BME in the medial aspect of the tibia between January 2005 and December 2015. BME was evaluated using magnetic resonance imaging (MRI). The sizes of the BME lesions were determined on the basis of the maximum diameter and were classified as small (<1 cm), medium (<2 cm), large (<4 cm), or very large (diffuse; >4 cm). Associations between preoperative BME severity and postoperative outcomes at a mean follow-up of 6.2 years (range, 2.0 to 14.3 years) were evaluated according to a Spearman correlation matrix with each reviewer's grades. Functional outcomes were assessed using the Hospital for Special Surgery (HSS) score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Society Score (KSS), and Short Form-12 (SF-12) questionnaire. Survival rate and complications were also evaluated.

RESULTS

The degree of preoperative BME was not significantly correlated with postoperative outcomes (p > 0.05). There were significant improvements between the preoperative and latest follow-up assessments in all functional outcome categories (p < 0.001). Patients demonstrated marked improvements with respect to pain, function, and quality of life. The overall survival rate was 95.2%, with a mean follow-up of 6.2 years. Six major complications were identified in 5.7% of the patients, and these resulted in 5 patients (4.8%) who had conversion to total knee arthroplasty.

CONCLUSIONS

We did not find any correlation between preoperative subchondral BME severity and postoperative outcomes. MOHTO showed good functional outcomes, a low major complication rate, and an excellent survival rate with a mean follow-up of 6.2 years, regardless of the degree of preoperative BME.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Relationship between the bony correction angle and mechanical axis change and their differences between closed and open wedge high tibial osteotomy

BACKGROUND

The purpose of this study was to investigate the relationship between the bony correction angle and mechanical axis change and their differences between closed wedge high tibial osteotomy (CWHTO) and open wedge high tibial osteotomy (OWHTO).

METHODS

A total of 100 knees of 89 patients who underwent OWHTO (50 knees) or CWHTO (50 knees) between 2011 and 2015 with a clinical follow-up for 1 year and a radiological follow-up for 1 month were investigated in a case control study. Anteroposterior radiographs of the knee and full-length leg were taken in the standing position using digital acquisition. The femorotibial angle (FTA), % mechanical axis deviation (MAD), % anatomical tibial axis deviation (ATAD), % mechanical tibial axis deviation (MTAD), mechanical medial proximal tibial angle (mMPTA), and joint line convergence angle (JLCA) were measured on preoperative and postoperative radiographs using a dedicated software.

RESULTS

CWHTO resulted in a greater variation between the tibial anatomical and mechanical axes than OWHTO (P <  0.05), and a greater soft tissue correction than OWHTO (P <  0.05). However, no significant difference was found between CWHTO and OWHTO in the ratio of MAD change to the correction angle. When the osteotomy was planned with the same bony correction angle, %MAD passed more laterally in OWHTO than in CWHTO (P <  0.05). These results suggested a lesser valgus bony correction ratio due to greater medial shift of the tibial axis and greater valgus compensation of the soft tissue in CWHTO compared to OWHTO.

CONCLUSIONS

The ratio of mechanical axis shift to the correction angle differed in preoperative planning, but postoperative alignment was comparable between opening wedge and closed wedge high tibial osteotomy.

Dome-shaped high tibial osteotomy with semi-circular Ilizarov pin fixator: Mid- to long-term results of a novel technique

BACKGROUND

The aim of this study was to assess the clinical and radiological results of the dome-shaped high tibial osteotomy (HTO) which was fixed with a novel construct comprised of semi-circular Ilizarov frames and pins.

METHODS

The patients with at least five years of follow-up were evaluated. One-hundred and thirty-two knees of 114 patients were included in the final analysis. The clinical evaluation included range of motion and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score. Anatomical femorotibial angle (aFTA), anatomical medial proximal tibial angle (aMPTA), tibial slope and Insall-Salvati ratio were calculated on standard weight-bearing radiographs.

RESULTS

The average aFTA was improved from 1.6° varus to 8.7° valgus (P < 0.001). The average WOMAC score (P < 0.001) and flexion value (P = 0.014) were improved at the latest follow-up (WOMAC: 17.2, flexion: 142.5) compared with the preoperative period (WOMAC: 59.6, flexion: 129.2). The sagittal radiological parameters were not significantly affected. The five-year survival was 96.2%, and 10-year survival was 83.3%.

CONCLUSIONS

The semi-circular Ilizarov pin construct provided satisfactory outcomes both clinically and radiologically at mid- to long-term follow-up.

Complications, Additional Surgery, and Joint Survival Analysis After Medial Open-Wedge High Tibial Osteotomy

The reported incidence of complications following medial open-wedge high tibial osteotomy (MOWHTO) varies. The authors sought to assess the complications, additional surgeries, and joint survival following MOWHTO in patients with isolated medial compartment arthrosis during a mean follow-up of 10 years. This retrospective study involved patients implanted with spacer plates, angle adjustable plates, or inverse L-type plates with wedges between 2000 and 2010. A total of 504 knees from 441 patients were examined. Mean age of the study population was 52.6±7.0 years, with 56 (11.1%) knees from men and 448 (88.9%) from women. The 10-year Kaplan-Meier joint survival rate was 94.8%. Overall complication rate for MOWHTO was 63.7%, with complications in 20.3% of treated knees requiring additional surgery. In this population, although the overall complication rate and the need for additional surgery were high, the need for additional surgery resulting from serious complications was low (2.6%). The high joint survival rate and low rate of additional surgery for serious complications indicate that MOWHTO can be safely applied in patients with isolated medial gonarthrosis. [Orthopedics. 2020;43(5):303-314.].

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.

Comparison of Clinical and Biomechanical Outcomes between Partial Fibulectomy and Drug Conservative Treatment for Medial Knee Osteoarthritis

Background

Upper partial fibulectomy has been preliminarily proved to have the efficacy for pain alleviation and improvement of function in patients with mild to moderate medial compartment knee osteoarthritis (KOA). However, the previous studies lack the control group with other treatments. The aim of this prospective, randomized controlled study is to compare the clinical and biomechanical effects between upper partial fibulectomy and drug conservative treatment on improvement of clinical pain, function, and gait for patients with mild to moderate medial knee osteoarthritis (KOA) and further discuss its biomechanical mechanism.

Methods

From August 2016 to February 2017, 49 and 48 patients with mild to moderate medial KOA were allocated to fibulectomy and drug groups. We assessed the patients' visual analog scale (VAS) pain score, Hospital for Special Surgery (HSS) knee score, limb alignment, passive flexion/extension range of motion (ROM) of the knee, and 3D gait kinematics and kinetics parameters before and after intervention. Repeated-measures ANOVA with Dunnett's post hoc assessment and multivariate analysis of variance were applied for intragroup and intergroup comparisons, respectively.

Results

The improvement in the fibulectomy group on the VAS pain score, HSS knee score, walking speed, and walking knee range of motion (ROM) was statistically better than that in the drug group. The decreased overall peak knee adduction moment (KAM) (decreased by 16.1%) and hip-knee-ankle (HKA) angle (decreased by 0.99° from a more varus alignment to a more neutral alignment) of the affected and operated side 1 year after surgery were observed in the fibulectomy group.

Conclusion

This research demonstrated that as a biomechanical intervention, upper partial fibulectomy can be a better choice in pain relief and function and gait improvement than drug conservative treatment for patients with early-stage knee OA. The long-term clinical outcomes, indication, and rationale for the improvement in clinical symptoms should be investigated further.

Opposite hinge fractures in high tibial osteotomy: a displacement subtype is more critical than a fracture type

PURPOSE

Analysis of the structure of the fractures of opposite hinge (FOH) after angle-stable closed-wedge (CW) and open-wedge (OW) high tibial osteotomy (HTO), and their influence on the development of tibial pseudarthrosis.

METHODS

187 CW and 94 OWHTOs were analyzed retrospectively. The FOHs in the OWHTO were classified according to Takeuchi, and in the CWHTO-according to the own classification with two types (depending on the direction of FOH). FOHs in both techniques were also subdivided into three subtypes according to displacement (A-non-displaced, B-primarily displaced, C-secondarily displaced). The statistical analysis included correlation analysis and logistic regression.

RESULTS

FOHs were found in 81 (43.3%) CW and 39 (41.2%) OWHTOs. The stable type 1 fractures predominated in OWHTO (76.9 vs. 42%, p < 0.001), the unstable type 2 FOHs prevailed in CWHTO (58 vs. 17.9%, p < 0.001). The tibial pseudarthrosis rate was higher with type 1 (20 vs. 12.9%, n.s.) and subtype A (16.7 vs. 6.8%, p = 0.048) FOHs in OWHTO, and with type 2 (20 vs. 0%, p < 0.001) and subtypes B (25 vs. 0%, p < 0.001) and C (29.4 vs. 25%, n.s.) in CWHTO (without FOHs 0.9% in CW and 1.8% in OWHTO, n.s.). Relevant correlations were detected between the pseudarthrosis rate and fracture type only in CWHTO (ρ_s = 0.298, p < 0.001, OR 24.87 for type 2) and displacement subtype in both groups (for subtype C: ρ_s = 0.345, p < 0.001, OR 43.75 and ρ_s = 0.231, p = 0.02, OR 18.0, respectively).

CONCLUSIONS

The unstable FOH types were more common in CWHTO. The displacement subtype was more predictive for the development of tibial pseudarthrosis than the fracture type, especially in OWHTO. The secondarily displaced FOHs (subtype C) represented the highest risk for the occurrence of pseudarthrosis in both techniques.

Comparison of radiological features of high tibial osteotomy and tibial condylar valgus osteotomy

Background

The purpose of this study was to compare radiological features between high tibial osteotomy (HTO) and tibial condylar valgus osteotomy (TCVO), in order to define the radiological indication criteria for TCVO.

Methods

Thirty-two cases involving 35 knees that had undergone HTO and the same number that had undergone TCVO for knee osteoarthritis were retrospectively evaluated. Characteristics of both groups did not differ significantly. Lower limb alignment, bone morphology, joint congruity, and joint instability were measured in standing full-length leg and knee radiographs obtained before and after surgery.

Results

Radiological features in the TCVO group included greater frequencies of advanced knee OA grade, varus lower limb malalignment, depression of the medial tibial plateau, and varus-valgus joint instability compared to the HTO group before surgery. However, tibial morphology, alignment of the lower limb, and joint instability improved to comparable levels after surgery in both groups.

Conclusions

TCVO appears preferable in cases with advanced knee OA, destroyed or inclined medial tibial plateau, widened and subluxated lateral joint, and high varus-valgus joint instability.

Deep peroneal nerve palsy after opening wedge high tibial osteotomy: A case report

RATIONALE

Peroneal nerve injury is one of the major complications that may occur after closing wedge high tibial osteotomy (CWHTO). In contrast, the reduced risk of the peroneal nerve injury has been considered as one of the advantages of opening wedge HTO (OWHTO).

PATIENT CONCERNS

A 61-year-old male who underwent OWHTO showed a dropped big toe immediately after surgery.

DIAGNOSIS

Injury of deep peroneal nerve was confirmed by electrodiagnostic study. It was probably caused by a posterolaterally protruded screw.

INTERVENTIONS

The protruded screw was replaced with a shorter one 3 weeks after OWHTO.

OUTCOMES

The motor weakness and sensory reduction were completely recovered at 9 months after surgery.

LESSONS

OWHTO has been known to be safe from peroneal nerve injury. However, considering the anatomical course of deep peroneal nerve, great care should be taken to avoid damage to the deep peroneal nerve while drilling holes and inserting distal screws toward the posterolateral aspect of the proximal tibia.

Improved Methods to Measure Outcomes After High Tibial Osteotomy

Observational studies suggest high tibial osteotomy produces substantial improvements in knee loading and stability that can limit the progression of joint damage; decrease pain; improve function and quality of life; and delay the need for knee replacement surgery. It can be cost-effective in knee osteoarthritis. However, systematic reviews and clinical practice guidelines are unable to provide strong recommendations, because limited high-level evidence supports its therapeutic value versus other treatments. We describe findings suggesting it can improve outcomes important to knee joint structure and function, patient quality of life, and health care systems. Future clinical trials are warranted and required.

[Complication analysis after angle-stable CW and OW high tibial osteotomy]

BACKGROUND

High tibial osteotomy (HTO) is a good joint-preserving alternative to joint replacement in the treatment of isolated medial varus gonarthrosis. It is, however, accompanied by a number of complications, which can compromise the outcome of the treatment.

OBJECTIVES

Analysis and comparison of the complication structure after angle-stable navigated closed wedge (CW) HTO and conventional angle-stable open wedge (OW) HTO, as well as determination of influence factors.

MATERIAL AND METHODS

281 HTO (187 CW- and 94 OWHTO) were analyzed retrospectively. Age, sex, BMI, time of surgery and radiological parameters were included as possible influence factors. A statistical analysis was performed with binary logistic regression.

RESULTS

An overall complication rate of 21.4% was revealed (25.1% after CW- and 13.8% after OWHTO, p = 0.02); the major complications occurred after 13.9% CW- and 10.6% OWHTO (p = 0.27); minor complications were observed after 11.2% CW- and 3.2% OWHTO (p = 0.03). This difference results from complications specific to CWHTO (peroneal lesions and pseudarthrosis fibulae). The incidence of pseudarthrosis tibiae was equal in both procedures (7.5%). Age ≥ 52 years and body mass index (BMI) ≥ 30 kg/m² were the relevant predictors for mechanical complications after CWHTO; these were not relevant for OWHTO.

CONCLUSION

The correct patient selection is essential to avoid postoperative complications after HTO. The overall complication rates are lower after OWHTO, mainly through the avoidance of complications typical for CWHTO. OWHTO offers a wider choice with respect to the selection of patients.

Hybrid closed wedge high tibial osteotomy improves patellofemoral joint congruity compared with open wedge high tibial osteotomy

PURPOSE

To evaluate clinical outcomes and radiographic changes in patellofemoral (PF) joint congruity between open wedge high tibial osteotomy (OWHTO) and hybrid closed wedge HTO (HCWHTO).

METHODS

From 2011 to 2013, 36 knees in 31 patients who underwent OWHTO and 21 knees in 17 patients who underwent HCWHTO were evaluated in this retrospective study with a minimum 5-year follow-up. Radiological outcomes including hip-knee-ankle angle (HKA), femoral patellar height index (FPHI), preoperative PF osteoarthritis (OA) grade, medial and lateral joint spaces of the PF joint, and congruence angle were measured. Clinical parameters including the Knee injury and Osteoarthritis Outcome Score (KOOS) and the Oxford Knee Score (OKS) were also evaluated. Preoperative and final follow-up values for each procedure were compared in outcome analyses.

RESULTS

Mean preoperative HKA and the degree of PF-OA were significantly more severe for patients treated with HCWHTO compared with those treated with OWHTO (p = 0.001, p = 0.0001). Mean postoperative FPHI was significantly decreased with proximalization of the patella in HCWHTO (p = 0.01) but showed no significant change in OWHTO (n.s.). Regarding PF joint congruity after HCWHTO, lateral joint space and congruence angle were significantly improved (p = 0.0001, p = 0.005), while medial joint space was not significantly changed (n.s.). After OWHTO, congruence angle showed no significant difference (n.s.), but medial and lateral joint spaces were significantly decreased (p = 0.0001, p = 0.018). There were no significant differences in KOOS and OKS between the groups (n.s., n.s.).

CONCLUSIONS

Although degrees of varus knee and PF-OA were more severe in HCWHTO than those in OWHTO, HCWHTO led to improved PF joint congruity, and its mid-term clinical outcomes were equivalent to those of OWHTO. Therefore, in patients with varus knee combined with PF-OA preoperatively, HCWHTO is a more effective treatment than OWHTO.

LEVEL OF EVIDENCE

Therapeutic level III.

Clinical efficacy of preoperative 3D planning for reducing surgical errors during open-wedge high tibial osteotomy

Increases in posterior tibial slope (PTS) with open-wedge high tibial osteotomy (OWHTO) are often related to two surgical errors: Symmetric opening of the osteotomy gap and a tendency to open the gap from the anteromedial direction. The study objective was to define trends in these two errors using computer simulation and clinical effects of their countermeasures. First, 60 knees with varus deformity were assessed with three-dimensional (3D) planning using computed tomography to allow for the mechanical axis to pass through a point at 62.5% of the width of the tibial plateau, defined as the weight-bearing line percentage (WBL%). Anterior and posterior widths of the opening gap to maintain PTS were measured. The effect on PTS when osteotomy gaps were opened from the anteromedial direction up to 30° was evaluated. Mean anterior width (y) was 6.6 mm (range, 2.2-10.9) and mean posterior width (x) was 9.1 mm (range, 3.9-15.7), which can be expressed as y = 0.75x - 0.24. Opening gaps from the anteromedial direction at 10°, 20°, and 30° led to a mean PTS increase of 1.9°, 3.9°, and 5.6°, respectively. In most cases, WBL% with anteromedial opening at 30° passed through a point at less than 60%. In 47 knees that underwent OWHTO using 3D planning, postoperative coronal and sagittal bone corrections were mostly accurate. However, postoperative WBL% was negatively correlated with correction angle because of difficulties in predicting medial joint tightness. Preoperative 3D planning for OWHTO can reduce surgical errors, but postoperative WBL% remains variable. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Complications Associated With Medial Opening-Wedge High Tibial Osteotomy Using a Locking Plate: A Multicenter Study

BACKGROUND

The aim of this study is to investigate complications following medial opening-wedge high tibial osteotomy using a locking plate. In addition, we aimed to compare postoperative outcomes between the complicated and the uncomplicated group.

METHODS

This study enrolled 209 patients who underwent medial opening-wedge high tibial osteotomy between 2010 and 2015. Patients with a follow-up period of at least 2 years were enrolled. Medical records and radiologic data were retrospectively reviewed. The complications were assessed up to postoperative 2 years and categorized into major and minor complications. The preoperative and postoperative clinical statuses were assessed using the Western Ontario McMaster University Osteoarthritis Index.

RESULTS

The mean patient age was 56.4 ± 5.9 years. Overall complication rate was 29.7%. Minor complications included undisplaced lateral hinge fracture (12.0%), hardware irritation (1.4%), displaced lateral hinge fracture (2.4%), delayed wound healing (1.9%), undisplaced lateral tibial plateau fracture (1%), and superficial wound infection (1%). Major complications were symptomatic hardware which needed hardware removal (4.8%), deep wound infection (1.9%), hardware failure with correction loss (1%), nonunion (0.5%), and early conversion to arthroplasty (0.5%). Most complications occurred intraoperatively (30.6%) and within 3 months postoperatively (40.3%). The major complication group showed a statistically higher Western Ontario McMaster University Osteoarthritis Index score than did other groups at postoperative 1 year (P = .013) and 2 years (P = .001).

CONCLUSION

The overall complication rate was 29.7%. Most complications were minor. The most common complication was undisplaced lateral hinge fracture. Major complications occurred in 8.6%. The major complication group showed significantly worse clinical outcomes than did the uncomplicated and minor complication groups.

Advances in modern osteotomies around the knee : Report on the Association of Sports Traumatology, Arthroscopy, Orthopaedic surgery, Rehabilitation (ASTAOR) Moscow International Osteotomy Congress 2017

Corrective lower limb osteotomies are innovative and efficient therapeutic procedures for restoring axial alignment and managing unicompartmental knee osteoarthritis. This review presents critical insights into the up-dated clinical knowledge on osteotomies for complex posttraumatic or congenital lower limb deformities with a focus on high tibial osteotomies, including a comprehensive overview of basic principles of osteotomy planning, biomechanical considerations of different implants for osteotomies and insights in specific bone deformity correction techniques. Emphasis is placed on complex cases of lower limb osteotomies associated with ligament and multiaxial instability including pediatric cases, computer-assisted navigation, external fixation for long bone deformity correction and return to sport after such osteotomies. Altogether, these advances in the experimental and clinical knowledge of complex lower limb osteotomies allow generating improved, adapted therapeutic regimens to treat congenital and acquired lower limb deformities.

Development and validation of a finite element model to simulate the opening of a medial opening wedge high tibial osteotomy

Medial opening wedge high tibial osteotomy (MOWHTO) is a surgical procedure intended to alter the coronal and sagittal plane alignment of the lower limb to primarily relieve the symptoms of osteoarthritis in the medial compartment of the knee. The purpose of this work was to develop and validate a finite element model to simulate the opening of a high tibial osteotomy and determine whether a pilot hole at the cortical hinge reduces the risk of lateral cortical fracture. Fifteen models were reconstructed from CT images of eight cadaveric specimens. The validated models indicated that the addition of the pilot hole increased the stresses and likelihood of a type-I and type-II fractures during the opening of a medial open wedge high tibial osteotomy compared to the no-hole condition.

The effect of plate design, bridging span, and fracture healing on the performance of high tibial osteotomy plates: An experimental and finite element study

Objectives

Opening wedge high tibial osteotomy (HTO) is an established surgical procedure for the treatment of early-stage knee arthritis. Other than infection, the majority of complications are related to mechanical factors – in particular, stimulation of healing at the osteotomy site. This study used finite element (FE) analysis to investigate the effect of plate design and bridging span on interfragmentary movement (IFM) and the influence of fracture healing on plate stress and potential failure.

Materials and Methods

A 10° opening wedge HTO was created in a composite tibia. Imaging and strain gauge data were used to create and validate FE models. Models of an intact tibia and a tibia implanted with a custom HTO plate using two different bridging spans were validated against experimental data. Physiological muscle forces and different stages of osteotomy gap healing simulating up to six weeks postoperatively were then incorporated. Predictions of plate stress and IFM for the custom plate were compared against predictions for an industry standard plate (TomoFix).

Results

For both plate types, long spans increased IFM but did not substantially alter peak plate stress. The custom plate increased axial and shear IFM values by up to 24% and 47%, respectively, compared with the TomoFix. In all cases, a callus stiffness of 528 MPa was required to reduce plate stress below the fatigue strength of titanium alloy.

Conclusion

We demonstrate that larger bridging spans in opening wedge HTO increase IFM without substantially increasing plate stress. The results indicate, however, that callus healing is required to prevent fatigue failure.

Cite this article: A. R. MacLeod, G. Serrancoli, B. J. Fregly, A. D. Toms, H. S. Gill. The effect of plate design, bridging span, and fracture healing on the performance of high tibial osteotomy plates: An experimental and finite element study. Bone Joint Res 2018;7:639–649. DOI: 10.1302/2046-3758.712.BJR-2018-0035.R1.

Intraoperative computer-assisted prediction of intraarticular contact pressures in the knee during high tibial osteotomy

OBJECTIVES

To develop an accurate intraoperative method to estimate changes in intraarticular contact pressures during high tibial osteotomy (HTO).

METHODS

Changes in knee alignment and pressure were monitored in real time in seven cadaver specimens that received HTO. Intraarticular contact pressure (N/mm² ) in each knee compartment was estimated based on extraarticularly acquired data (leg alignment, correction, and ankle tilt) and based on the application of an axial force of half bodyweight (400-450 N).

RESULTS

Contact pressure estimation was more accurate in the lateral compartment (R²  = 0.940) than in the medial compartment of the knee (R²  = 0.835). The optimism-corrected R² was 0.936 for the lateral compartment and 0.821 for the medial compartment.

CONCLUSIONS

We have established a framework for estimating the change in intraarticular contact pressures based on extraarticular data. This research could be helpful in generating appropriate algorithms to estimate joint alignment changes based on applied loads.

More accurate correction can be obtained using a three-dimensional printed model in open-wedge high tibial osteotomy

PURPOSE

The purpose of this study was to compare the accuracy of the preoperative planning method using a three-dimensional (3D) printed model with that of a method using picture archiving and communication system (PACS) images in high tibial osteotomy (HTO).

METHODS

Patients who underwent HTO using a 3D printed model (20 patients) and a method based on PACS images (20 patients) from 2012 to 2016 were compared. After obtaining the correction angle, in the 3D printed method, the wedge-shaped 3D printed model was designed. The PACS method used preoperative radiographs. The accuracy of HTO for each method was compared using radiographs obtained at the first postoperative year. The preoperative and postoperative posterior tibial slope angles were also compared.

RESULTS

The weight-bearing line was corrected 21.2 ± 11.8% from preoperatively to 61.6 ± 3.3% postoperatively in the 3D group and from 19.4 ± 12.3% to 61.3 ± 8.1% in the PACS group. The mean absolute difference with the target point was lower in the 3D group (2.3 ± 2.5) than in the PACS group (6.2 ± 5.1; p = 0.005). The number of patients in an acceptable range was higher in the 3D group than in the PACS group. The posterior tibial slope angle was not significantly different in the 3D group (8.6°-8.9°), but was significantly different in the PACS group (9.9°-10.5°, p = 0.042).

CONCLUSIONS

In open-wedge HTO, a more accurate correction for successful results could be obtained using the 3D printed model.

LEVEL OF EVIDENCE

IV.

Gait retraining using real-time feedback in patients with medial knee osteoarthritis: Feasibility and effects of a six-week gait training program

BACKGROUND

The knee adduction moment (KAM) is often elevated in medial knee osteoarthritis (KOA). The aim of this study was to evaluate effects on KAM and patient-reported outcomes of a six-week gait training program.

METHODS

Twenty-one patients (61 ± 6 years) with KOA participated in a six-week biofeedback training program to encourage increased toe-in (all patients) and increased step-width (five patients). Patients received real-time visual feedback while walking on an instrumented treadmill. We analysed the effect of the gait modification(s) on peak KAM in week six and three and six months post-training. We also evaluated the effect on pain and functional ability.

RESULTS

Of 21 patients starting the program, 16 completed it with high attendance (15 and 16 respectively) at the three and six month follow-ups. First peak KAM was significantly reduced by up to 14.0% in week six with non-significant reductions of 8.2% and 5.5% at the follow-ups. Functional ability (assessed using the WOMAC questionnaire) improved significantly after the training (eight point reduction, p = 0.04 in week six and nine point reduction, p = 0.04 at six-month follow-up). There was also a trend towards reduction in WOMAC pain (p = 0.06) at follow-up.

CONCLUSIONS

Biofeedback training to encourage gait modifications is feasible and leads to short-term benefits. However, at follow-up, reductions in KAM were less pronounced in some participants suggesting that to influence progression of KOA in the longer term, a permanent regime to reinforce the effects of the training program is needed. Trial number: ISRCTN14687588.