Does obesity and nicotine abuse influence the outcome and complication rate after open-wedge high tibial osteotomy? A retrospective evaluation of five hundred and thirty three patients

Medial opening wedge high tibial osteotomy performs similarly irrespective of body mass index

PURPOSE

This study investigates the effect of the body mass index (BMI) on the early (2 years) to midterm (5 years) results of medial opening wedge high tibial osteotomy (MOWHTO).

METHODS

A prospectively maintained single-centre database of 1138 knee osteotomies, between 2002 and 2022, was retrospectively reviewed. Adult patients who underwent MOWHTO for symptomatic unicompartmental medial knee osteoarthritis (OA), with varus knee malalignment, having failed conservative management, were included. Patients were categorized into three groups according to their BMI as per the classification from the National Institute for Health and Care Excellence (NICE): the healthy weight (HW) group (BMI of 18.5-24.9 kg/m2), the overweight (OW) (BMI of 25-29.9 kg/m2), and the obesity (OB) group (BMI ≥ 30 kg/m2). Multiple patient-reported outcome measures (n = 6) were recorded preoperatively and at 2 and 5 years postoperatively. Deformity analysis was undertaken preoperatively and postoperatively. The relative risk (RR) of the complications between the HW, OW and OB groups was calculated. The rate of conversion to arthroplasty, and 5 and 10 years survivorship were recorded, as well as the hazard ratio (HR) of BMI on survivorship.

RESULTS

A total of 574 cases were included in the study: the HW group (n = 96), the OW group (n = 233) and the OB group (n = 245), with a mean BMI of 23 ± 1.5 kg/m2, 27.4 ± 1.4 kg/m2 and 34.4 ± 3.8 kg/m2, respectively. The mean follow-up was 13.3 years (4.8-20.3). The mean mechanical tibiofemoral angle corrections were in the HW group: 7.1 ± 3°, OW group: 6.6 ± 3.5° and OB group: 7.1 ± 3.8°, with no intergroup significant difference (p = n.s.). Clinically, despite lower preoperative scores in the OW and OB groups, no difference was observed postoperatively amongst the three groups. The overall complication rate was 12.5% in the HW group, 6.8% in the OW group, and 9.8% in the OB group. There was no significant difference in the RR of complications between the HW and OW groups (RR = 0.6, 95% confidence interval [CI] = 0.3-1.3) (p = 0.2), and the HW and OB groups (RR = 0.8; 95% CI = 0.3-2.2) (p = 0.7). There was no overall significant difference in survival outcomes based on the BMI between the three groups (p = 0.4). The HR of conversion to arthroplasty between the HW and OW groups was 1.4 [95% CI = 0.6-3.5](p = 0.5) and between the HW and OB groups was 1.8 [95% CI = 0.8-4.4] (p = 0.2).

CONCLUSION

BMI has no significant effect on either the radiological corrections, clinical outcomes, complications or survivorship of MOWHTO at short- to medium-term follow-up. No specific cutoff point for BMI can be recommended as a contraindication to MOWHTO.

LEVEL OF EVIDENCE

Level IV, Retrospective cohort study.

Intraoperative radiographic analysis and adjustment of the optimal position of plate in high tibial osteotomy

BACKGROUND

When high tibial osteotomy is performed for genu varus deformity, it is not easy to determine the accurate placement of the plate.

PURPOSE

To determine a simple way to assess the position of the plate, to provide more effective mechanical support and to reduce the risk of implant rupture and vascular injury.

MATERIAL AND METHODS

Two human anatomical marks, the patellar ligament and semimembranosus, were connected and divided into four parts to identify points Ⅰ, Ⅱ, and Ⅲ. These points determined the areas for Tomofix placement: anterior, anterolateral, and lateral. Simulated internal fixation placed hole B of Tomofix at points Ⅰ (anterior), Ⅱ (anterolateral), and Ⅲ (lateral). We analyzed the pointing direction of the locking screws in Tomofix holes on MRI to assess potential injury risk to the popliteal neurovascular bundle.

RESULTS

In the X-ray: holes B and C appeared as the plate in the anterior, only hole C appeared as the plate in the anterolateral, and none of the holes appeared as the plate in the lateral. In the general view of the sawbones, the screw pointed towards the popliteal neurovascular bundle when the plate was in the anterior.

CONCLUSION

If a small number of holes on the plate is visible under fluoroscopy, then several lateral positions of the plate can be obtained; the direction of the screw tunnel tends to deviate from the popliteal neurovascular bundle with the posterior position of the plate.

Obesity does not impact complications and conversion to total knee arthroplasty after high tibial osteotomy: A systematic review

PURPOSE

The purpose of this systematic review is to consolidate outcomes of obese patients undergoing high tibial osteotomy and to investigate the effect of obesity on postoperative outcomes, including symptomatic relief and time to conversion to arthroplasty.

METHODS

Medline, Embase and Cochrane Library were searched from database inception up to April 2023 according to PRISMA guidelines by two reviewers. Search terms including 'obesity', 'BMI', 'osteotomy' and 'high tibial osteotomy (HTO)' were included to identify all relevant articles. Only studies that explicitly reported outcomes for obese patients were included. Disagreements in study inclusion or quality assessment were resolved by a senior third reviewer. Metrics compared include time to arthroplasty, preoperative and postoperative mechanical tibiofemoral angle (mTFA), patient-reported satisfaction scores and postoperative complications.

RESULTS

Nine studies comparing 973 patients were included. The mean age was 52.7 ± 4.2 years old and 38.4% were male. Six studies performed the medial opening-wedge HTO, and three utilized the medial wedge closing technique. Most studies indicated significant improvement following surgical intervention with satisfactory outcomes in obese and nonobese patients. In addition, differences in complication rates were minimal between obese and nonobese patients (n.s.), while functional scores did not vary significantly. Conversion to total knee arthroplasty was not found to increase in obese patients (n.s.).

CONCLUSION

Obesity does not appear to carry a greater complication risk or worse outcomes following high tibial osteotomies, and surgeons should consider HTO a viable option for young obese patients with symptomatic unicompartmental chondral wear with coronal limb malalignment.

LEVEL OF EVIDENCE

Level IV.

Osteotomy for treating knee osteoarthritis from 2012 to 2023: Bibliometric analysis and global trends

BACKGROUND

Numerous surgical interventions are available for the treatment of knee osteoarthritis (KOA). In recent years, knee-preserving surgery, specifically osteotomy, has gained significant attention from patients, particularly those who are young and physically active, as it not only effectively alleviates pain but also preserves bone integrity, thereby allowing for potential future joint replacement. This study aims to comprehensively analyze the global application trends of osteotomy for KOA and identify the current research hotspots.

METHODS

We conducted a literature search encompassing English-language studies on osteotomy for KOA published from 2012 to 2023 in the Web of Science Core Collection (WoSCC) database. Bibliometric analysis tools, including VOSviewer, CiteSpace, and R Studio, were employed to analyze global trends and research hotspots.

RESULTS

We analyzed 1520 eligible publications, comprising 1350 articles and 170 reviews. The number of articles on osteotomy for KOA has exhibited a consistent upward trend over the past decade. The top 3 contributing countries (South Korea, United States, and China) accounted for 45.98% of all published articles. U.S. scholars exhibited high productivity, prominence, and academic impact in this field. Seoul National University published the most papers on the relationship between osteotomy and KOA, while Sungkyunkwan University had the highest average citation rate. Among authors, Yong Seuk Lee from Korea and Steffen Schroeter from Germany had the highest number of publications and average citation values, respectively. Research interests were clustered into 5 categories: "High tibial osteotomy," "Biomechanics of osteotomy," "Osteotomy combined with cartilage repair techniques," "Postoperative prognosis and outcomes," and "Improvement of surgical techniques."

CONCLUSION

Recent years have witnessed notable rapid progress in the research on osteotomy for KOA. The field is poised for continued growth in terms of academic literature. The United States has emerged as a global leader in knee osteotomy research, while Korea demonstrates considerable potential in this domain. Future research hotspots may encompass high tibial osteotomies, osteotomies combined with cartilage repair techniques, and advancements in surgical techniques for KOA.

Earlier consolidation and improved knee function of medial open wedge high tibial osteotomy with autologous bone graft

PURPOSE

Medial knee osteoarthritis can be treated with medial open wedge high tibial osteotomy (OWHTO). We sought to investigate osseous consolidation of the osteotomy with and without autologous bone grafts (ABG) to detect possible benefits of ABG in osseous healing and functional outcome.

METHODS

In this prospective study, patients without graft transplantation were compared to those receiving ABG after medial OWHTO. They were followed up 6 weeks, 12 weeks, 6 months and 12 months postoperatively. Radiographic progress of consolidation, clinical scores, contrast-enhanced ultrasound (CEUS) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) were assessed at each appointment.

RESULTS

A total of 35 patients were enrolled, 20 without and 15 with graft transplantation. Radiologic evaluation showed a significantly earlier consolidation of the osteotomy gaps (p = 0.012) in patients with ABG, resulting in a significantly higher rate of consolidation 12 months after surgery (60% without bone graft vs. 100% with bone graft, p = 0.006). At 6 weeks as well as 6-month follow-up, a tendency of earlier consolidation with ABG was apparent, but not statistically significant (6 weeks: 50% vs. 80%, p = 0.089; 6 months: 30% vs. 60%, p = 0.097). CEUS and DCE-MRI showed physiological perfusion of the osteotomy gaps in both groups. A tendency to better function and less pain in patients with ABG was recognizable.

CONCLUSION

In our study, autologous bone grafting evocated earlier osseous consolidation after medial OWHTO and showed a tendency to a better functional outcome.

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.

High tibial osteotomy versus unicompartmental knee arthroplasty for Kellgren-Lawrence grade 3-4 knee osteoarthritis in younger patients: comparable improvements in patient-reported outcomes, adjusted for osteoarthritis grade and sex

PURPOSE

Previous studies comparing high tibial osteotomy (HTO) with unicompartmental knee arthroplasty (UKA) have seldom accounted for differing patient characteristics between both groups. This study compared patient-reported outcomes (PROs) of HTO and UKA patients, adjusted for preoperative PROs, osteoarthritis grade and sex.

METHODS

A retrospective study was performed analysing prospectively collected PROs, namely the Oxford Knee Score (OKS) and pain/satisfaction scores, collected preoperatively and at 6 months, 12 months and 24 months postoperatively. Consecutive medial opening-wedge HTOs and medial UKAs from 2016-2019, with a preoperative Kellgren-Lawrence grade ≥ 3, aged 50-60 years, were included. Linear mixed model analyses, with the OKS over time as the primary outcome, were used.

RESULTS

We included 84 HTO patients (mean age 55.0 ± 3.0, 79% male, mean BMI 27.8 ± 3.4, 75% Kellgren-Lawrence grade 3) and 130 UKA patients (mean age 55.7 ± 2.8, 47% male, mean BMI 28.7 ± 4.0, 36% Kellgren-Lawrence grade 3). Response rates were ≥ 87% at all time points. Corrected for preoperative PROs, Kellgren-Lawrence grade and sex, the HTO group had a 2.5 (95% CI 1.0-4.0) points lower OKS over time than the UKA group (p = 0.001). The Numeric Rating Scale scores (NRS; 0-10) for pain at rest and during activity were higher (p < 0.01) in the HTO group. The EQ-5D-descriptive system (p < 0.01), NRS satisfaction (p < 0.01), anchor function and pain scores (p < 0.01) were lower over time in the HTO group.

CONCLUSION

UKA patients had better OKS scores, pain and satisfaction scores over time than HTO patients. However, the observed differences were below their established minimal clinically important differences. Therefore, from the patients' perspective, HTO did not appear to be inferior to UKA under the indications outlined in this study. Level of evidence Level IV.

The effect of smoking on union rates following corrective osteotomies around the knee: A systematic review and meta-analysis

BACKGROUND

Distal femur osteotomies (DFO) and high tibial osteotomies (HTO), are well-established treatment options for joint preservation in active patients with uni-compartmental osteoarthritis. Optimal outcomes are contingent on adequate preoperative evaluation of patient-specific factors. This systematic review and meta-analysis aims to explore the difference in union rates between smokers and non-smokers following corrective osteotomies around the knee.

METHODS

A systematic search of the MEDLINE and EMBASE databases was performed in accordance with the PRISMA guidelines to identify studies reporting smoking status in adults who developed delayed and/or non-union following HTO or DFO. Studies were pooled using a random effect model [Review Manager (RevMan) software, V.5.4] and heterogeneity was estimated using I2.

RESULTS

Data for meta-analysis was available for 1,406 osteotomies from 10 studies, performed in patients with mean age ranging from 38-54 years, and 65% were male. The union rate among non-smokers was 97.3% (1100/1131) compared with 89.5% (246/275) among smokers; OR 4.59 [95% CI 1.99 to 10.62], p-value < 0.001. Subgroup analysis revealed that the risk of non-union in smokers after opening wedge osteotomy was almost double (OR 4.8) that of closing wedge osteotomies (OR 2.9).

CONCLUSION

Smoking increases the risk of non-union during elective knee osteotomy surgery. Our findings also suggest that smokers have a better chance of achieving union with closing wedge osteotomy compared to open wedge osteotomy.

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

Background

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

Purpose/Hypothesis

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

Study Design

Cohort study; Level of evidence, 3.

Methods

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

Results

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

Conclusion

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

IV.

Long-term Outcomes after Medial Open Wedge High Tibial Osteotomy - A Retrospective Study of 69 Patients

High tibial osteotomy (HTO) is a widespread option to avoid or delay total knee arthroplasty (TKA). The present study aimed to assess the long-term survival rate and postoperative subjective knee function after isolated medial open wedge HTO in patients with symptomatic medial compartment knee osteoarthritis (OA) and varus malalignment.Sixty-nine patients (48.8 ± 6.7, 35-66 years; preoperative mechanical tibiofemoral angle [mTFA] -5.3 ± 3.4; -14.9-0.0° varus) treated with medial open wedge HTO using a TomoFix plate were included in this retrospective study, with a follow-up of at least 10 years (11.8 ± 1.0 years). The survival rate after HTO was calculated after 5 and 10 years. Subjective knee function was assessed using Hospital for Special Surgery (HSS), Oxford knee, Lequesne, and Lysholm scores.Thirty-three patients underwent conversion to TKA, on average, 7.0 ± 3.4 (1.3-13.7) years after HTO. Five- and ten-year survival rates were 84.1 and 60.9%, respectively. Patients without conversion to TKA showed a Lysholm score of 64.5 (35-92), Lequesne score of 7 (1-13), HSS score of 71 (56-86), and Oxford knee score of 38.5 (25-44) at the last follow-up (more than 10 years). Significantly higher scores were registered at the last follow-up compared to the preoperative state regarding the Lysholm score (preoperative: 43.5 [12-95]; follow-up: 64.5 [35-92]; p < 0.001). The HSS score (preoperative: 69.5 [43-93]; follow-up: 71 [56-86]; p = 0.6941) showed no statistically significant change during the 10-year follow-up period. The Lequesne score was significantly lower than the preoperative score (preoperative: 11.5 [0.5-22]; follow-up: 7 [1-13]; p < 0.001), indicating a lower handicap.The majority of patients with a valgus medial compartmental knee OA treated with HTO with fixation using the TomoFix plate can expect no conversion to TKA for more than 10 years. Furthermore, patients without conversion to TKA after 10 years still had a significantly higher subjective knee function than preoperatively. Further research is needed to identify risk factors for conversion to TKA. This helps to guide surgeons in selecting patients who will benefit most from HTO.

Comparison of the Miniaci and Dugdale techniques on functional outcomes in medial open wedge high tibial osteotomy

PURPOSE

To compare the correction angles determined by the Miniaci and Dugdale techniques in patients treated with medial open wedge high tibial osteotomy (MOWHTO) and show their impact on clinical outcomes.

METHODS

Seventy-four patients constituted the study group. The correction angles in Group 1 were measured using the Miniaci technique, and those in Group 2 were measured using the Dugdale technique. The clinical evaluations included the Tinetti Gait and Balance Assessment (TGBA), the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) scores, and the Visual Analogue Scale (VAS). The effect of the correction angle on the patient's clinical outcomes was evaluated. Measurement techniques were also changed between groups for comparison.

RESULTS

Seventy-four patients (62 females, 12 males) with a mean age of 53.7 ± 4.9 years were followed up for a mean of 67.4 ± 5.5 months. The TGBA, WOMAC, and VAS scores were improved at the last follow-up compared to the preoperative scores (p < 0.05). The preoperative TGBA and WOMAC scores were not significantly different between the two groups, but the last follow-up TGBA and WOMAC scores in Group 2 were worse than those in Group 1 (p < 0.05). When measuring techniques were changed, the preoperative correction angle (PCA) value and the last follow-up correction angle (LFCA) value were lower in Group 1 measured with the Dugdale technique but higher in Group 2 measured with the Miniaci technique (p < 0.05).

CONCLUSION

Since the correction angle values measured with the Miniaci technique in MOWHTO are higher than those measured with the Dugdale technique; the functional results are better.

LEVEL OF EVIDENCE

Retrospective cohort study, III.

[Treatment of unicompartmental osteoarthritis of the knee]

Osteoarthritis of the knee is one of the most important degenerative joint diseases in the clinical routine. The treatment of knee osteoarthritis is not only based on the stage, symptoms and duration of the joint disease, but also depends on the existing arthrosis pattern. In the case of unicompartmental arthrosis, damage typical for osteoarthritis is limited to just one joint compartment. Both the conservative and the surgical treatment of unicompartmental osteoarthritis of the knee have to respect the individual characteristics of the respective forms of osteoarthritis. In the context of this manuscript, the genesis, the diagnostics and the guideline-based stage-adapted conservative and operative treatment of unicompartmental osteoarthritis of the knee are addressed.

The results of allogenic cancellous bone graft in medial opening wedge high tibial osteotomy

PURPOSE

There is no clear consensus regarding the optimal filling agent in the medial opening wedge high tibial osteotomy (MOWHTO). In this study, we evaluated the clinical and radiologic outcomes of MOWHTO with an allogeneic cancellous bone graft and TomoFix plate.

METHODS

Medical profiles of 122 patients who underwent MOWHTO with cancellous bone graft from iliac crest were retrospectively reviewed. One hundred and two patients (120 knees) who met the study criteria were included in the analysis. The osteotomy site was fixed with a TomoFix plate. The mean age of the patients was 40.85 ± 22.15 years. The mean follow-up of the patients was 33.2 ± 29 months. The primary outcome measures were the union of osteotomy site and loss of correction that were investigated on postoperative radiographs. Secondary outcome measures were postoperative complications that were extracted from the patients' medical records.

RESULTS

Union of the osteotomy site was observed in all patients within three months after the operation. Loss of correction at the osteotomy site occurred in two knees (1.7%), both of which underwent revision surgery. Three patients had non-infected prolonged wound drainage and underwent reoperation for allograft removal. Nine other complications were also recorded that did not require intervention, including superficial infection (n = 2), compartment syndrome (n = 1), deep vein thrombosis (n = 1), loss of knee flexion (n = 2), and transient pain at the site of the osteotomy (n = 3).

CONCLUSION

Allogenic cancellous bone graft provides efficient gap healing in MOWHTO and can be used as an effective alternative to the autogenous bone graft.

Using multivariate nonlinear mixed-effects model to investigate factors influencing symptom improvement after high tibial osteotomy in combination with bone marrow concentrate injection for medial compartment knee osteoarthritis: a prospective, open-label study

PURPOSE

To investigate the effects of various demographic, structural, radiographic, and clinical factors on the prognosis of patients with medial compartmental knee osteoarthritis with varus deformity undergoing medial opening wedge high tibial osteotomy (HTO) in combination with bone marrow concentrate (BMC) injection.

METHODS

In this prospective study, 20 patients underwent medial opening wedge HTO in combination with BMC injection with 12 months of follow-up. The structural and radiographic outcomes were evaluated by femorotibial angle and posterior tibial slope angle. The clinical outcomes were evaluated by visual analogue scale (VAS), Western Ontario and McMaster Universities Arthritis Index (WOMAC), and The Knee injury and Osteoarthritis Outcome Score (KOOS). Multivariate nonlinear mixed-effects models with asymptotic regressions were used to model the trajectory of symptom improvement.

RESULTS

Medial opening wedge HTO in combination with BMC corrected the malalignment of the knee and led to significant symptom relief. The improvement of clinical symptoms reached a plateau 6 months after the surgery. Greater symptom severity at baseline and lower Kellgren-Lawrance (KL) grades were correlated with better post-operative clinical outcomes. Body-Mass-Index (BMI), femorotibial angle, age, and sex may also play a role in influencing the extent of symptom relief.

CONCLUSION

Symptom severity at baseline is important for prognosis prediction. In clinical practice, we suggest that the evaluation of clinical features and functional status of the patients be more emphasised.

Comparing Unicompartmental Knee Arthroplasty and High Tibial Osteotomy for Isolated Medial Compartment Knee Osteoarthritis

»

Both unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) allow for compartment-specific intervention on an arthritic knee joint that preserves bone stock and native soft tissue compared to a total knee arthroplasty (TKA). Both operations give a more natural feeling with native proprioception compared with a TKA.

»

HTO is better suited in patients who are younger (<55 years-of-age), have a body mass index (BMI) <30 kg/m2, high activity requirements, mechanical malalignment, asymmetric varus, isolated anterior cruciate ligament insufficiency, need for multiplanar correction, and a preference for joint preserving interventions. Recent data suggest that age (>55 years-of-age) should not solely contraindicate a HTO.

»

UKA may be chosen in patients who are older (>55 years-of-age), low activity requirements, have a BMI <40 kg/m2, severe osteoarthritis with significant joint space narrowing, acceptable coronal alignment, symmetric varus, and patient preference for arthroplasty.

Superior survivorship and plate-related results of TomoFix compared to Puddu plate fixation for opening-wedge high tibial osteotomy: A systematic review of the literature

PURPOSE

This systematic review aimed to compare survivorship and plate-related results of Puddu and TomoFix plates in opening-wedge high tibial osteotomy (OWHTO).

METHODS

PubMed, Scopus, EMBASE, and CENTRAL databases were searched from January 2000 until September 2021 for clinical studies involving patients with medial compartment knee disease and varus deformity undergoing OWHTO using the Puddu or TomoFix plating systems. We extracted survival data, plate-related complications, and functional and radiological outcomes. The risk of bias assessment had been carried out using Cochrane Collaboration's quality assessment tool for randomised controlled trials (RCTs) and Methodological Index for Non-Randomised Studies (MINORS).

RESULTS

Twenty-eight studies were included. The total number of knees was 2568 in 2372 patients. The Puddu plate was used in 677 knees, while the TomoFix plate was used in 1891. The follow-up ranged from 5.8 to 147.6 months. Both plating systems were able to delay conversion to arthroplasty at different follow-up intervals. However, osteotomies fixed by the TomoFix plate achieved higher survival rates, especially at mid-term and long-term follow-ups. In addition, fewer complications were reported with the TomoFix plating system. Although both implants achieved satisfactory functional outcomes, high scores could not be maintained throughout long-term intervals. Regarding radiological results, TomoFix plate was able to achieve and maintain larger degrees of varus deformity, while preserving the posterior tibial slope.

CONCLUSIONS

This systematic review demonstrated the superiority of the TomoFix over the Puddu system as a safer and more effective fixation device in OWHTO. Nevertheless, these results should be interpreted with caution due to the lack of comparative evidence through high-quality RCTs.

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.

The use of tranexamic acid reduces blood loss in osteotomy at knee level: a systematic review

PURPOSE

Aim of this systematic review was to evaluate the literature regarding the effect of tranexamic acid (TXA) on the outcome after knee osteotomy.

METHODS

A systematic literature search was carried out in various databases on studies on the use of tranexamic acid in osteotomies around the knee. Primary outcome criterion was the hemoglobin (drop). Secondary outcome criteria were total blood loss, drainage volume, adverse effects such as thromboembolic events, blood transfusions, wound complications and clinical scores. A meta-analysis was performed for quantitative measures. The present study was registered prospectively ( www.crd.york.ac.uk/PROSPERO ; no.: CRD42021229624).

RESULTS

Seven studies with 584 patients (TXA group: 282 patients, non TXA group: 302 patients) Hemoglobin decrease (1.54 g/dl vs. 2.28 g/dl), blood loss (394.49 ml vs. 595.54 ml) and drainage volume (266.5 ml vs. 359.05 ml) were significantly less in the TXA group compared to the non TXA group. No thromboembolic event was noted in any study. In the non TXA group four blood transfusions were given. Eleven wound complications occurred in the non TXA group in comparison to two wound complications in the TXA group.

CONCLUSIONS

The results of the present study show that the application of TXA reduces hemoglobin drop, blood loss and drainage volume. These effects could be responsible for the lesser rate of side effects after administration of TXA during knee osteotomy.

Use of tranexamic acid in medial open wedge high tibial osteotomy

PURPOSE

Aim of this study was to evaluate the effect of tranexamic acid (TXA) on the outcome after medial open wedge osteotomy.

MATERIAL AND METHODS

A prospective non-randomized comparative study with 52 patients has been performed. In both treatment groups, the same surgical technique for the medial open wedge HTO was used. In group 1 (N: 26) the patients received 1 g TXA i.v. preoperatively, in group 2 (N: 26) no TXA was given. Primary outcome measure was the decrease in hemoglobin concentration. Secondary outcome criteria were postoperative pain, intraarticular effusion (measured by ultrasound), range of motion (ROM) at discharge, peri- and postoperative complications and the KOOS PS (pre- and postoperatively at 1 year follow up).

RESULTS

Hemoglobin decrease was significantly less in the TXA group compared to the non TXA group. Postoperative pain and intraarticular effusion was also significantly lower and ROM at discharge was higher in the TXA group. There was no group difference in peri- and postoperative complications and the pre- and postoperatively KOOS PS.

CONCLUSIONS

The results of the present study show the systemic application of 1 g TXA reduces hemoglobin drop and postoperative morbidity (pain, intraarticular effusion, and ROM) after tibial open wedge HTO.

Influence of lower-limb mechanical axis on the curative effect of medial high tibial osteotomy for knee osteoarthritis

PURPOSE

To investigate the effect of the ratio of the medial tibial plateau width to the total tibial plateau width on the therapeutic efficacy of high tibial osteotomy (HTO) on the medial side for the treatment of knee osteoarthritis.

METHODS

In this study, we retrospectively analyzed information of 278 patients who underwent medial HTO for knee osteoarthritis with varus deformity. The Tinetti Gait and Balance Assessment Tool, the Visual Analog Scale (VAS), and the Knee Society Scoring System (KSS) were used to comprehensively evaluate the function of the knee joint after HTO.

RESULTS

After adjusting for potential confounding factors (i.e., age, gender, body mass index/BMI, and surgical site), the Tinetti assessment score was optimized when the degree of correction was 53.67%, with the β-value on the left and right sides of the inflection point of 0.49 (confidence interval, CI: 0.20, 0.78, P = 0.0009) and- 0.26 (95% CI: - 0.30, - 0.22, P < 0.0001), respectively. The KSS score was optimized when the degree of correction was 55.45%, with the β-value on the left and right sides of the inflection point of 2.77 (95% CI: 1.64, 3.90, P < 0.0001) and - 1.18 (95% CI: - 1.46, - 0.91, P < 0.0001), respectively. The VAS score was the lowest when the degree of correction was 55.00%, with the β-value on the left and right sides of the inflection point of - 0.16 (95% CI: - 0.29, - 0.03, P = 0.0146) and 0.08 (95% CI: 0.05, 0.10, P < 0.0001), respectively. Stratified analysis showed that the BMI affected the Tinetti assessment score (β =  - 0.14, 95% CI: - 0.24, - 0.04, P = 0.0071). According to the smooth-curve fitting results, when the BMI was > 28, the Tinetti assessment score showed a negative trend.

CONCLUSION

The degree of lower-limb mechanical axis correction correlated with the functional status of the knee joint after MOW HTO. When the ratio of the medial tibial plateau width to the total tibial plateau width was approximately 55%, the post-MOW HTO outcomes were optimized and the patients experienced the highest satisfaction. In addition, very high BMI was not conducive for the postoperative recovery of the knee joint function.

LEVEL OF EVIDENCE

III Case-control study/Retrospective comparative study.

Perioperative complications in osteotomies around the knee: a study in 858 cases

INTRODUCTION

Eight hundred and fifty-eight consecutive osteotomies around the knee joint were analyzed retrospectively to detect intra- and early postoperative complications in a period of 4 weeks postoperative. Indications for osteotomy were unilateral gonarthritis or torsional deformities resulting in femoropatellar instability or anterior knee pain.

MATERIALS AND METHODS

Etiology of deformity, technique and mode of correction and level of osteotomy were registered. Complications were detected and divided in minor complication (superficial wound infection, and deep-vein thrombosis) and major complication (compartment syndrome, deep infection, and vascular lesion).

RESULTS

Fifteen major (1.7%) and 17 minor complications (2.0%) were detected: 5 vascular lesions (0.58%), 4 compartment syndromes (0.47%) and 6 deep infections (0.70%), 14 superficial wound infections (1.6%) and 3 deep-vein thrombosis (0.35%). In posttraumatic osteotomies and continuous corrections, risk for a superficial wound infection was significantly higher and with osteoclasia risk for vascular lesion was higher compared to osteotomy with oscillating saw. No difference was found for anatomical level of osteotomy and for the other complications in terms of etiology of deformity, technique of osteotomy and mode of correction.

CONCLUSION

Osteotomy around the knee is a safe procedure in the treatment of unicompartmental gonarthritis in terms of intra- and postoperative complications. Major complications are rare. Pit falls for compartment syndromes (LCW and torsional corrections) have to kept in mind. There is no difference in frequency of complications between HTO and supracondylar osteotomies. Risk for superficial wound infection is higher in posttraumatic osteotomies and with continuous corrections. Osteoclasia contains a higher risk for vascular lesion compared to oscillating saw.

Overweight patients benefit from high tibial osteotomy to the same extent as patients with normal weights but show inferior mid-term results

PURPOSE

The purpose of this prospective study was to analyze the impact of obesity on the clinical and radiological outcomes 6 years after open-wedge high tibial osteotomy (HTO).

METHODS

A total of 120 prospectively recorded patients with medial compartment osteoarthritis underwent open-wedge HTO between 2008 and 2011. The study cohort was frequently examined over a minimum of a 6-year follow-up. The cohort was divided into three groups according to body mass index (BMI): normal weight patients (BMI < 25 kg/m²), pre-obese patients (BMI 25-30 kg/m²) and obese patients (BMI > 30 kg/m²). Clinical and functional outcomes (Oxford Knee Score, Hospital for Special Surgery Score, Lequesne Score, Tegner Activity Scale), subjective health-related quality of life (SF-36), change in mechanical limb alignment (mTFA) as well as conversion to unicompartmental or total knee arthroplasty (TKA) were evaluated. To compare clinical scoring between the groups, univariate variance analysis was applied. Changes in outcome variables over time were analyzed with dependent t tests.

RESULTS

From 120 patients, 85 were followed-up over a 6.7-year period on average (6-11.8 years) after HTO. The mean BMI was 28.6 ± 4.6 kg/m². Each group showed a significant pre- to postoperative increase in all recorded scores (p < 0.05). In absolute terms, both mental and clinical scores of overweight patients did not reach the peak values of the normal weighted population during the period of observation. There was a conversion to TKA in 10.5% after an average of 50.1 ± 25.0 months following surgery. A total of five complications occurred without significant differences (BMI < 25: n = 1, BMI 25-30: n = 2, BMI > 30: n = 2; n.s.). There was a mean pre- to postoperative (six weeks after surgery) correction difference of 6.9° ± 3.2° (mTFA) with higher loss of correction over time in overweight patients.

CONCLUSION

In terms of clinical outcome and health-related quality of life, overweight patients may receive a benefit from open-wedge HTO to the same extent as patients with normal weights and show similar complication rates. However, they have inferior preoperative clinical and functional results and mid-term results after open-wedge HTO compared to patients with normal weights.

LEVEL OF EVIDENCE

Level III.

Long-Term Survivorship of Closed-Wedge High Tibial Osteotomy for Severe Knee Osteoarthritis: Outcomes After 10 to 37 Years

Background:

High tibial osteotomy (HTO) was developed as a joint-preserving procedure to treat relatively young patients with isolated medial compartmental knee osteoarthritis (OA). Long-term survivorship after HTO is important to determine whether patients will need additional surgery.

Purpose:

To determine the long-term (>35-year) survivorship and prognostic factors for closed-wedge HTO (CWHTO) for severe medial OA.

Study Design:

Case series; Level of evidence, 4.

Methods:

We retrospectively evaluated patients who underwent CWHTO for severe medial knee OA between 1983 and 2009 at our institution, Nagoya University Graduate School of Medicine (Nagoya, Japan). Patient demographics, follow-up period, and pre- and postoperative femoral-tibial angle (FTA) were reviewed. The patients or the relatives of the patients were interviewed by telephone to record postoperative status, including conversion to total knee arthroplasty (TKA).

Results:

Of the 74 CWHTO procedures performed, we evaluated 56 procedures in 45 patients (mean age at time of surgery, 56.8 years). The mean follow-up period was 17.1 years. Nine knees (16.1%) underwent conversion to TKA. The mean time to TKA conversion was 15.6 years. Kaplan-Meier analysis revealed a 10-year survival rate of 90.1%, a 15-year rate of 83.8%, a 20-year rate of 75.9%, and a 35-year rate of 75.9%. Log-rank test showed that age ≥55 years (P = .044), body mass index (BMI) ≥25 kg/m² (P = .0016), and preoperative FTA <185° (P = .0034) were risk factors associated with TKA conversion. Multivariate analyses adjusted for age and sex identified BMI ≥25 kg/m² (hazard ratio [HR], 13.4; 95% CI, 1.7-106.9; P = .014) and preoperative FTA <185° (HR, 4.2; 95% CI, 1.1-16.6; P = .04) as risk factors associated with TKA conversion.

Conclusion:

The survival rate of CWHTO for severe medial knee OA was 90.1% at 10 years, 83.8% at 15 years, and 75.9% at 20 years and 35 years. Furthermore, a BMI ≥25 kg/m² and FTA <185° were the independent risk factors associated with TKA conversion after CWHTO.

Role of high tibial osteotomy in medial compartment osteoarthritis of the knee: Indications, surgical technique and outcomes

Knee osteoarthritis (OA) is the most common joint disorder worldwide. In particular, primary knee OA often presents with a varus malalignment. This increases the loads going through the medial compartment resulting in cartilage degeneration and symptomatic arthritis. High tibial osteotomy (HTO) is the workhorse surgical procedure for treating medial knee OA. When performed precisely in the hands of an experienced surgeon, HTO can delay or avoid knee arthroplasty. Of note, outcomes of knee arthroplasty are at best unpredictable in patients of younger age. Hence, there is a growing need for joint preservation procedures for younger patients presenting with knee OA, of which HTO is one. Through this article, the authors of whom all are joint preservation surgeons with a special interest in osteotomy hope to share from their experience as well as the available literature on the indications, perioperative planning, surgical technique, outcomes as well as pearls and pitfalls of HTO.

Contemporary Knee Osteotomy in the United States: High Tibial Osteotomy and Distal Femoral Osteotomy Have Comparable Complication Rates despite Differing Demographic Profiles

Knee osteotomies show efficacy in slowing knee osteoarthritis progression and delaying the need for total knee arthroplasty in younger patients. Despite evolutions in indications, techniques, and hardware that have improved outcomes, longitudinal trends demonstrate a decline in high tibial osteotomy (HTO) and distal femoral osteotomy (DFO) use. Unfortunately, knowledge of the current usage and complications associated with HTO and DFO is limited. The purpose of this study was to compare the preoperative demographics and early complication rates of HTO and DFO. We analyzed the HTOs and DFOs performed between 2006 and 2017 using the ACS-NSQIP (American College of Surgeons National Surgical Quality Improvement Program) database. We compared both groups for preoperative patient demographics (sex, age, race, body mass index [BMI]) and health status variables including functional scores, ASA (American Society of Anesthesiologists) scores, smoking status, and other comorbidities. Emergency and elective status of the patient case, length of hospital stay, operation time, and 30-day postoperative complications were also analyzed. After the exclusion criteria were applied, 321 HTO and 295 DFO patients were included in the final analysis. The HTO group had higher proportions of younger (p < 0.001) and male (p < 0.001) patients with higher BMI (p = 0.007). Racial profiles were similar between the two groups (p = 0.575). Preoperatively, those in the HTO group had more functional independence, better physical status scores, and fewer chronic conditions (p < 0.05). There were no statistically significant differences between HTO and DFO in operative time, postoperative complications, readmission, and reoperation. HTO patients, however, had shorter hospital stays (p < 0.001). Although there are differences in preoperative and operative characteristics of HTO and DFO, early postoperative complications are similar for both groups. Therefore, HTO and DFO can be considered safe and effective treatment options for younger patients with symptomatic unicompartmental knee osteoarthritis.

Association of Gap Healing With Angle of Correction After Opening-Wedge High Tibial Osteotomy Without Bone Grafting

Background:

Studies have reported that opening wedge high tibial osteotomy (OWHTO) without bone grafting has outcomes that are similar to or even better than those of OWHTO with bone grafting, especially after use of a locking plate. However, a consensus on managing the gap after OWHTO has not been established.

Purpose:

To determine the degree of gap healing achieved without bone grafting, the factors associated with gap healing, and whether additional gap healing would be obtained after plate removal.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

This retrospective study included 73 patients who underwent OWHTO without bone grafting between 2015 and 2018. Patients in the study were divided into 2 groups based on the correction angle: small correction group (<10°; SC group) and large correction group (≥10°; LC group). The locking plate used in OWHTO was removed at a mean of 13.5 months after surgery in 65 patients. Radiographic indexes were measured: gap filling height, gap vacancy ratio (GVR), and osteotomy filling index. The acceptable gap healing was defined as an osteotomy filling index ≥3. The factors related to gap healing around the osteotomy site were selected after multicollinearity analysis.

Results:

Although both groups achieved acceptable gap healing regardless of the correction angle, the SC group showed higher and earlier gap healing than did the LC group (gap healing rate 81.4% in the SC group vs 41.7% in the LC group at 3 months postoperatively). The GVR was 8.6% in the SC group and 15.3% in the LC group at 12 months after surgery (P = .005). Both the amount of time that elapsed after surgery and the correction angle were associated with gap healing (P < .05). Additional gap healing was observed after plate removal, as the GVR decreased 2.7% more in the patients with plate removal than in patients who did not have plate removal (P = .012).

Conclusion:

All patients achieved acceptable gap healing without bone graft. The degree of gap healing was higher in the SC group and increased over time. Gap healing was promoted after plate removal. Considering the results of this study, a bone graft is not necessary in routine OWHTO in terms of gap healing.

The degree of correction in open-wedge high tibial osteotomy compromises bone healing: A consecutive review of 101 cases

BACKGROUND

The bone healing in open-wedge high tibial osteotomy (OWHTO) proceeds gradually by a filling of the osteotomy gap. This can comprise several risk factors.

METHODS

A retrospective study analysed the clinical and radiological course of 101 consecutive OWHTOs in 96 patients. The following risk factors were considered: age, body mass index, tobacco consumption, amount of tobacco consumption, severity of comorbidities, infection of the surgical area, occurrence of a lateral hinge fracture and the degree of correction. The bone healing was evaluated by using the modified Radiographic Union Score for Tibial fractures (RUST).

RESULTS

A disturbance in bone healing was observed in 16 of the 101 osteotomies. Binary logistic regression analysis showed a correlation between the angle of the opening wedge and the development of a disturbance in bone healing (P = 0.002). The odds ratio indicated an increase in the risk of a disturbance in bone healing of 56% with each additional degree of correction. For the risk factor 'age' a statistical trend was recognizable (P = 0.077) with the risk of a disturbance in bone healing in higher age.

CONCLUSION

Lateral hinge fractures seem not to have a detrimental effect on the filling of the osteotomy gap. An increase in the opening wedge bears the risk of a disturbance in bone healing.

Patient-specific instrumentation (PSI) Referencing High Tibial Osteotomy Technological Transfer and Education: protocol for a double-blind, randomised controlled trial (PROTECTED HTO Trial)

INTRODUCTION

High tibial osteotomy (HTO) is a treatment of choice for active adult with knee osteoarthritis. With advancement in CT imaging with three-dimensional (3D) model reconstruction, virtual planning and 3D printing, patient-specific instrumentation (PSI) in form of cutting jigs is employed to improve surgical accuracy and outcome of HTO. The aim of this randomised controlled trial (RCT) is to explore the surgical outcomes of HTO for the treatment of medial compartment knee osteoarthritis with or without a 3D printed patient-specific jig.

METHODS AND ANALYSIS

A double-blind RCT will be conducted with patients and outcome assessors blinded to treatment allocation. This meant that neither the patients nor the outcome assessors would know the actual treatment allocated during the trial. Thirty-six patients with symptomatic medial compartment knee osteoarthritis fulfilling our inclusion criteria will be invited to participate the study. Participants will be randomly allocated to one of two groups (1:1 ratio): operation with 3D printed patient-specific jig or operation without jig. Measurements will be taken before surgery (baseline) and at postoperatively (6, 12 and 24 months). The primary outcome includes radiological accuracy of osteotomy. Secondary outcomes include a change in knee function from baseline to postoperatively as measured by three questionnaires: Knee Society Scores (Knee Scores and Functional Scores), Oxford Knee Scores and pain visual analogue scale (VAS) score.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Joint Chinese University of Hong Kong - New Territories East Cluster Clinical Research Ethics Committee (CREC no. 2019.050), in accordance with the Declaration of Helsinki. The results will be presented at international scientific meetings and through publications in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04000672; Pre-results.

Non-Union Treatment Based on the "Diamond Concept" Is a Clinically Effective and Safe Treatment Option in Older Adults

Background

Patients >60 years suffering from non-unions are often unable to perform activities of daily living and often become dependent on nursing care. Evidence regarding treatment options and outcome is nonexistent. This study sought to determine the clinical effectiveness and safety of one- or two-step non-union therapy in elderly patients.

Methods

This study was a single-site retrospective database analysis of older adults with long bone non-unions treated via “diamond concept”. All medical records of patients receiving surgical treatment of non-unions between 01/01/2010 and 31/12/2016 were reviewed. Clinical and radiological outcome subsequent to non-union therapy were evaluated.

Results

A total of 76 patients (37 patients were treated with one-step and 39 patients with Masquelet therapy) suffering from a non-union older than 60 years treated between 01/01/2010 and 31/12/2016 in our institution were included into the current study. Bone consolidation was achieved in 91.9% after one-step and 76.9% after the Masquelet therapy. Analysis of age as a risk factor in the outcome of non-union therapy revealed no significant differences in patients treated with the one-step procedure according to the “diamond concept”. On the contrary, age had a significant negative influence on the outcome of the Masquelet therapy (p = 0.027).

Conclusion

Non-union therapy according to the “diamond concept” is an effective and reliable treatment option in elderly patients. According to findings of the current study, older adults suffering from an infected non-union benefit from a two-stage procedure, whereas in patients suffering from a non-infected non-union, a one-step surgical treatment is beneficial.

Comparative analysis of fixation configurations and their effect on outcome after medial open-wedge high tibial osteotomy

PURPOSE

The purposes of this study were to analyze and compare 1) the postoperative fixation configurations, and 2) radiological and clinical outcomes between the new conceptual fixation device (LCfit) and the conventional locking plates.

METHODS

Retrospective comparative analysis of 304 cases who underwent open-wedge high tibial osteotomy with four different locking plate systems including the LCfit system was conducted. In analyzing the fixation configuration of each locking plate system, the plate position, the gap between plate and bone, screw angle, and screw length were evaluated from postoperative CT scans. The clinical outcomes and radiological parameters of four patient groups corresponding to the four locking plate systems were also compared.

RESULTS

In the analysis of the fixation configurations, the LCfit system showed more posteromedial plate position, decreased gap between plate and bone, reduced screw angle, and longer screw length compared to the other three locking plates. However, there were no significant differences in clinical outcomes and radiological parameters such as hip-knee-ankle angle, weight-bearing line position, medial proximal tibial angle, and posterior slope between the four groups.

CONCLUSION

The newly designed fixation system (LCfit) for open-wedge high tibial osteotomy showed fixation configurations that have theoretical mechanical advantages over conventional anatomical locking plates. However, there were no significant differences in clinical outcomes and radiological parameters between LCfit and the other locking plate systems.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Plate-related results of opening wedge high tibial osteotomy with a carbon fiber reinforced poly-ether-ether-ketone (CF-PEEK) plate fixation: a retrospective case series of 346 knees

BACKGROUND

While open wedge high tibial osteotomy (owHTO) is an established standard procedure to treat medial osteoarthritis of the knee in combination with varus deformity, it bears the risk of postoperative hardware failures and lateral cortical hinge fractures. This in turn can lead to an accelerated osteoarthritis, non-union, or a loss of correction accuracy. The purpose of the study was to evaluate the radiologic outcomes of owHTO with a carbon fiber reinforced poly-ether-ether-ketone (CF-PEEK) plate fixation in patients with medial osteoarthritis and varus deformity.

METHODS

Three hundred twenty-four consecutive patients (346 knees) who were treated with owHTO using the PEEKPower HTO plate were included in this retrospective study; 89.9% of the patients were overweight or obese. Patients were followed by conventional radiographs over a 12-month period. Typical plate-related results such as the time and quality of gap healing as well as the correction accuracy were analyzed. Furthermore, the number of lateral cortex fractures was determined.

RESULTS

Bony consolidation was observed after a mean gap healing time of 4.0 ± 1.7 months independent on the patients' weight (p = 0.2302). With increasing gap sizes, bony healing was significantly prolonged (p < 0.001). Additionally, patients with greater gap sizes had a significantly increased risk for a lateral cortex fracture (p = 0.0041). However, none of the patients had a non-union 1 year postoperative. A hinge fracture occurred in 30% of patients. Hinge fractures with Takeuchi grades I and II increased the gap healing time compared to no fracture (p = 0.0069 and p = 0.0002, respectively), but only 1.2% of patients with hinge fracture had a clinical relevant loss of correction ≥ 3 mm. No implant failures were found.

CONCLUSIONS

Open wedge HTO using the PEEKPower HTO plate for patients with medial osteoarthritis of the knee in combination with tibial varus deformity leads to excellent bony consolidation also in cases with a hinge fracture, a gap size > 12 mm as well as for severely obese patients.

Bone autografting in medial open wedge high tibial osteotomy results in improved osseous gap healing on computed tomography, but no functional advantage: a prospective, randomised, controlled trial

PURPOSE

Medial open wedge high tibial osteotomy (owHTO) is a valuable surgical technique used to manage medial degeneration in varus knees. Iliac crest autograft is considered the gold standard gap-filler. It was hypothesised that iliac crest autograft promotes gap healing and improves functional outcome in owHTO.

METHODS

Between 2005 and 2009, patients scheduled to undergo owHTO stabilised by a medial locking compression plate were randomised to undergo owHTO either with iliac crest autograft (group A) or without bone void filler (group B). Pre- and postoperative leg axes were recorded. At 3 and 12 months postoperatively, the healing of the osteotomy gap was measured as a percentage on CT images, and functional scores were recorded.

RESULTS

There were 15 patients in group A, and 25 in group B. The groups were similar in age, sex ratio, knee varus deformity, body mass index, and smoking status. Group A and B had similar preoperative varus (6.9° vs. 7.6°) and postoperative valgus (2.2° vs. 3.0°). Compared with the control group, group A had a significantly greater degree of osseous gap healing after 3 months (40.1% vs. 10.8%, p = 0.045) and 12 months (91.5% vs. 59.1%, p ≤ 0.001). Multiple linear regression analysis found that bone grafting was an independent promoting factor for gap healing, while increased preoperative varus was an independent retardant factor at 3 months (p = 0.004 and p = 0.002, respectively) and 12 months (p ≤ 0.001 and p = 0.003, respectively). Younger age was a promoting factor for gap healing on CT at 3 months (p ≤ 0.001), but not at 12 months. No correlations were found between bone healing and functional outcome, body mass index, or smoking status.

CONCLUSIONS

Iliac crest autograft significantly increases healing of the osteotomy gap after owHTO. Increased preoperative varus and older patient age are independent factors that delay early healing of the osteotomy. However, no functional advantage was found at 3 or 12 months postoperatively. Therefore, routine use of iliac crest autograft cannot be recommended.

LEVEL OF EVIDENCE

II.

Higher BMI predicts additional surgery at the time of ACL reconstruction

PURPOSE

Despite public recognition, obesity is a growing epidemic affecting an estimated 34% of adults and 20% of children in the U.S.

POPULATION

As such, the number of ACL reconstructions performed in this population is likely to increase. The goal of this study is to evaluate the risk that increasing BMI poses for additional surgery at the time of ACL reconstruction.

METHODS

A retrospective analysis of the American College of Surgeons' National Surgical Quality Improvement Program's (ACS-NSQIP) database for the years 2005-2015 was conducted. Logistic regressions were used to assess the relationship between BMI and additional CPT codes for internal derangement at the time of ACL reconstruction. Internal derangement was defined as any CPT code for treatment of a meniscus tear, chondral lesion, or loose body removal. Surgeries for multi-ligamentous knee injuries were excluded.

RESULTS

A total of 11,403 patients undergoing ACL reconstruction were identified. 41.9% of patients had an associated CPT code for internal derangement. As BMI increased, there was a corresponding increase in the odds of additional surgery. Specifically, for every 1.0 increase in BMI, the risk of additional surgery increased by 1.6% (p < 0.001). Compared to patients with a BMI of 18.5-24.9, those with a BMI 25-29.9 had an odds ratio (OR) of 1.112, BMI 30-34.9 had an OR of 1.137, BMI 35-39.9 had an OR of 1.249, and those ≥ 40 had an OR of 1.442 for additional surgery (p < 0.001).

CONCLUSIONS

This nationally-representative, population-based study demonstrates that patients with elevated BMI are much more likely to require additional surgery in the setting of primary ACL reconstruction. This risk correlates with increasing BMI. Surgeons should keep these risks in mind when evaluating and counseling patients for surgery in the setting of ACL reconstruction.

LEVEL OF EVIDENCE

Case-control study, Level III.

High tibial osteotomy increases patellofemoral pressure if adverted proximal, while open-wedge HTO with distal biplanar osteotomy discharges the patellofemoral joint: different open-wedge high tibial osteotomies compared to an extra-articular unloading device

PURPOSE

Valgus high tibial osteotomy (HTO) and a recently introduced extra-articular absorber have been shown to efficiently unload the medial compartment of the knee. However, only little is known about the influence of these treatment modalities on biomechanics of the patellofemoral joint. The purpose of this study was to investigate and compare the impact of different HTO techniques and implantation of an extra-articular absorber on patellofemoral contact forces.

METHODS

Fourteen fresh frozen cadaveric knees were tested in a specially designed knee simulator that allowed simulation of isokinetic flexion-extension motions under physiological loading. Mean contact pressure (ACP) and peak contact pressure (PCP) of the patellofemoral joint was measured continuously between 0° and 120° of knee flexion using a pressure sensitive film in the following conditions: native, after biplanar medial open-wedge HTO with 5° and 10° correction angle performing an ascending frontal osteotomy of the tibial tuberosity, and after implantation of an extra-articular absorber system (KineSpring®). Including a second testing cycle with a biplanar medial open-wedge HTO with 5° and 10° correction angle performing descending frontal osteotomy of the tibial tuberosity. Values after each procedure were compared to the corresponding values of the native knee.

RESULTS

Biplanar proximal osteotomy leaded to a significant increase of retropatellar compartment area contact pressure compared to the first untreated test cycle (Δ 0.04 ± 0.01 MPa, p = 0.04). Similar results were observed measuring peak contact pressure (Δ 1.41 ± 0.15 MPa, p = 0.03). With greater correction angle 5°, respectively, 10° peak and contact pressure increased accordingly. In contrast, the biplanar distal osteotomy group showed significant decrease of pressure values (p = 0.004). The extracapsular, extra-articular absorber had no significant influence on pressure levels in the patellofemoral joint.

CONCLUSION

HTO with a proximal biplanar osteotomy of the tuberositas tibia significantly increased patellofemoral pressure conditions depending on the correction angle. In contrast a distally directed biplanar osteotomy diminished these effects while implantation of an extracapsular, extra-articular absorber had no influence on the patellofemoral compartment at all. Consequently, patients with varus alignment with additional retropatellar chondropathia should be treated with a distally adverted osteotomy to avoid further undesirable pressure elevation in the patellofemoral joint.

Patient Evaluation and Indications for Osteotomy Around the Knee

Osteotomy is recognized as a knee joint-preserving surgical procedure to treat frontal and/or sagittal plane malalignment with or without associated instability. This article outlines the preoperative clinical and imaging assessments of prospective patients undergoing osteotomy. In addition, indications and contraindications as well as surgical planning are presented.

[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.

Smoking and obesity influence the risk of nonunion in lateral opening wedge, closing wedge and torsional distal femoral osteotomies

PURPOSE

Lateral distal femoral osteotomies (DFO) have recently been performed more frequently. In addition to realignment for varus and valgus deformity, the indication was extended with the introduction of torsional osteotomies in patellofemoral instability. The purpose of this study was to assess the general and technical risk factors for nonunion in lateral opening, closing and torsional DFO.

METHODS

A total of 150 lateral DFO [98 opening wedge (LOWDFO) and 52 closing wedge (LCWDFO)] were analyzed in regard to potential risk factors for nonunion until plate removal. Nonunion was defined as failure of osseous consolidation according to clinical and radiological evaluation.

RESULTS

In LOWDFO, the nonunion rate was 2%, in LCWDFO the rate was higher with 9.6%. Nicotine abuse (p = 0.009) and a higher body mass index (p = 0.003) were significant risk factors. Patient's age and gender, the wedge height, hinge fractures, monoplanar versus biplanar osteotomy as well as additional torsional osteotomies were not significant in regard of nonunion.

CONCLUSIONS

Lateral DFO have a low rate of complications and nonunion. Smoking and obesity were significantly associated with the risk of nonunion. Hinge fractures, monoplanar technique or complete bone cuts of the opposite hinge in torsional osteotomies did not negatively influence the nonunion rate in DFO.

LEVEL OF EVIDENCE

Level IV.

The Effect of Tobacco Smoking on Musculoskeletal Health: A Systematic Review

This systematic review explored associations between smoking and health outcomes involving the musculoskeletal system. AMSTAR criteria were followed. A comprehensive search of PubMed, Web of Science, and Science Direct returned 243 articles meeting inclusion criteria. A majority of studies found smoking has negative effects on the musculoskeletal system. In research on bones, smoking was associated with lower BMD, increased fracture risk, periodontitis, alveolar bone loss, and dental implant failure. In research on joints, smoking was associated with increased joint disease activity, poor functional outcomes, and poor therapeutic response. There was also evidence of adverse effects on muscles, tendons, cartilage, and ligaments. There were few studies on the musculoskeletal health outcomes of secondhand smoke, smoking cessation, or other modes of smoking, such as waterpipes or electronic cigarettes. This review found evidence that suggests tobacco smoking has negative effects on the health outcomes of the musculoskeletal system. There is a need for further research to understand mechanisms of action for the effects of smoking on the musculoskeletal system and to increase awareness of healthcare providers and community members of the adverse effects of smoking on the musculoskeletal system.

Ten-Year Results of Medial Open-Wedge High Tibial Osteotomy and Chondral Resurfacing in Severe Medial Osteoarthritis and Varus Malalignment

BACKGROUND

High tibial osteotomy (HTO) is a widely used treatment option for medial osteoarthritis and varus malalignment, especially in young patients with early osteoarthritis. Limited outcome data are available for this procedure in severe osteoarthritis, and no long-term data are available using newer implants.

PURPOSE

To determine survivorship and functional results of medial open-wedge HTO combined with a chondral resurfacing (CR) procedure (abrasion plus microfracture) in severe medial osteoarthritis (Kellgren-Lawrence grade 3 and 4) and varus malalignment. Furthermore, factors that potentially influence the outcome were analyzed.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

From September 2005 to December 2008, all cases of HTO (fixation with an angular-stable internal fixator) combined with CR were prospectively surveyed with regard to survival (Kaplan-Meier-method, not requiring arthroplasty) and functional outcome (subjective International Knee Documentation Committee [IKDC] score). Cartilage regeneration at the time of hardware removal, tibial bone varus angle (TBVA), pre- and postoperative mechanical medial proximal tibial angle (MPTA), and postoperative alignment were analyzed with regard to the result.

RESULTS

Seventy-nine knees were included (73 patients; mean age 50.9 ± 7.6 years). The follow-up rate was 90% at 10.0 ± 1.2 years (range, 8.3-12.1 years). Pre- and postoperative mechanical tibiofemoral axis were 9.6° ± 3.0° of varus and 0.6° ± 2.7° of valgus, respectively. Survival rate was 81.7% (95% CI, 72.5%-90.9%) at 10 years. Subjective IKDC score significantly improved from 44 ± 11 preoperatively to 70 ± 13 at one, 66 ± 15 at three, 66 ± 15 at five, and 65 ± 17 at ten years ( P < .001 at any point of follow-up). Poor cartilage regeneration and low preoperative IKDC score (<40) were associated with decreased survival. High preoperative TBVA was associated with better and an overcorrected MPTA (>95°) with inferior functional outcome at final follow-up, respectively.

CONCLUSION

Even in cases of severe medial osteoarthritis and varus malalignment, HTO in combination with a CR procedure is a good to excellent treatment option. The role of the CR procedure remains unclear. Although good results are obtained with overcorrected MPTA, long-term functional outcome is inferior.

What Determines the Success of Closed-Wedge High Tibial Osteotomy: Severity of Malalignment, Obesity, Follow-up Period, or Age?

Objectives:

High tibial osteotomy (HTO) is a well-established procedure for the treatment of medial knee osteoarthritis originating from malalignment of the lower extremity. The current study was designed to evaluate the clinical and radiographic results of closed-wedge HTO for the treatment of medial knee osteoarthritis and to reveal factors affecting the outcome.

Methods:

A retrospective study was conducted with 138 patients who were operated on for medial knee osteoarthritis between 2000 and 2007 using closed-wedge HTO. Preoperative and follow-up physical examination findings, body mass index (BMI) values, and Hospital for Special Surgery (HSS) and Lysholm knee scores were reviewed. Radiographic evaluation included measurement of the mechanical axis preoperatively and the most recent follow-up orthoroentgenograms. The follow-up knee scores were evaluated according to preoperative mechanical axis, obesity, age, follow-up period, and gender of the patient. The mechanical axis measurement was assessed based on obesity, age, and follow-up period.

Results:

The mean preoperative and latest follow-up mechanical axis was 4.92^o±4.24^o varus and 3.43^o±3.74^o valgus, respectively (p=0.0001). Improvement in the Lysholm (p=0.0001) and HSS (p=0.0001) knee scores was significant. The preoperative mechanical axis, obesity, follow-up period, and gender had no negative effect on the follow-up knee scores, whereas a preoperative age over 50 years had a negative effect on the follow-up knee score. Obesity and the length of the postoperative follow-up period did not have a negative effect on the postoperative mechanical axis, whereas a preoperative age over 50 had a negative effect on the postoperative mechanical axis.

Conclusion:

The results of this study suggest that medial knee osteoarthritis may be treated successfully with closed-wedge HTO. The analysis indicated that factors such as obesity, the degree of preoperative deformity, and gender do not adversely affect the success of treatment. However, a preoperative age over 50 adversely affected the outcome.

Management of an Infected Nonunion of an Opening-Wedge High Tibial Osteotomy with 2-Stage Implantation of Rotating Hinge Knee Prosthesis

Introduction

High tibial osteotomy (HTO) is a frequent and effective treatment for unicompartmental gonarthritis. Only a few articles are focused on the treatment of infected nonunion.

Patient and Method

A 50-year-old obese patient was operated on by medial opening-wedge HTO. She developed a painful nonunion treated by hardware removal, allograft, and plate fixation. However, the nonunion persisted. 2 years later, cellulitis appeared with an abscess adjacent to the HTO plate. Despite surgical debridement and antibiotics, septic knee arthritis occurred. In a situation of infected nonunion and septic arthritis with chondrolysis, she was scheduled for a 2-stage total knee replacement (TKR). The infected tibial articular block was first resected and replaced by a cement spacer. After a short interval, the TKR was implanted. After 2 years, the patient walked pain-free with good knee function.

Discussion

In the literature, different efficient treatments exist for infected nonunion after HTO, but comprehensive studies are missing for a consensus treatment. Current data are mostly based on case reports, since this pathology is quite rare.

Conclusion

In a difficult situation of infected nonunion with septic knee arthritis, we performed a 2-stage knee prosthesis implantation. This led to an early mobilization and fast recovery.

Functional results following high tibial osteotomy: a review of the literature

Introduction

High tibial osteotomy (HTO) is an operation used to treat patients with medial compartment knee osteoarthritis. The United Kingdom Knee Osteotomy Registry (UKKOR) has been set up to gather contemporaneous data on HTO throughout the patient journey. UKKOR uses a variety of patient-reported outcome measures (PROMs) to gauge the surgical outcome.

Aim

The aim of this review is to analyse the published literature that has used PROMs to assess the outcomes following HTO.

Methodology

Two searches of the literature were performed and compiled highlighting 95 articles of interest. After screening and manual additions, 23 manuscripts were reviewed and appraised using the appropriate Critical Appraisal Skills Programme Checklist (Kai et al. in PLoS Med 4(11):1766–1775, 2007).

Results and discussion

There is a variety of published literature on HTO with a varied approach to the use of PROMs. Their use has increased recently, and studies have demonstrated that they are appropriate assessment tools for monitoring outcomes following HTO. In all of the studies that compared pre-operative to post-operative PROMs, there have been significant improvements. However, the data are varied due to differing study designs which in some instances have significant limitations.

Conclusion

PROMs are effective ways to measure outcomes following HTO. They can also be useful in predicting outcome. The heterogeneity of the data and limitations of the study designs limit the transferability of the data. It is therefore important to analyse data from a multi-surgeon, multi-centre source that uses robust and constant pre- and post-operative PROMs.

Effect and safety of early weight-bearing on the outcome after open-wedge high tibial osteotomy: a systematic review and meta-analysis

INTRODUCTION

The purpose of this systematic review and meta-analysis was to evaluate the effectiveness and safety of early weight-bearing by comparing clinical and radiological outcomes between early and traditional delayed weight-bearing after OWHTO.

MATERIALS AND METHODS

A rigorous and systematic approach was used. The methodological quality was also assessed. Results that are possible to be compared in two or more than two articles were presented as forest plots. A 95% confidence interval was calculated for each effect size, and we calculated the I ² statistic, which presents the percentage of total variation attributable to the heterogeneity among studies. The random-effects model was used to calculate the effect size.

RESULTS

Six articles were included in the final analysis. All case groups were composed of early full weight-bearing within 2 weeks. All control groups were composed of late full weight-bearing between 6 weeks and 2 months. Pooled analysis was possible for the improvement in Lysholm score, but there was no statistically significant difference shown between groups. Other clinical results were also similar between groups. Four studies reported mechanical femorotibial angle (mFTA) and this result showed no statistically significant difference between groups in the pooled analysis. Furthermore, early weight-bearing showed more favorable results in some radiologic results (osseointegration and patellar height) and complications (thrombophlebitis and recurrence).

CONCLUSION

Our analysis supports that early full weight-bearing after OWHTO using a locking plate leads to improvement in outcomes and was comparable to the delayed weight-bearing in terms of clinical and radiological outcomes. On the contrary, early weight-bearing was more favorable with respect to some radiologic parameters and complications compared with delayed weight-bearing.