Radiographic measures of settlement phenomenon in patients with medial compartment knee osteoarthritis. Clin Rheumatol. 2016;35:1573-1578. [PMID: 26712497 DOI: 10.1007/s10067-015-3146-0]

Proximal fibular osteotomy definitively ameliorates medial compartment knee osteoarthritis: A finite element analysis

Objective

This study was designed to explore the biomechanical impacts of the proximal fibular osteotomy (PFO) on medial compartment knee osteoarthritis (KOA). Furthermore, this study utilized finite element analysis (FEA) to examine the biomechanical impacts of PFO on medial compartment KOA both pre- and post-surgery.

Methods

Fifteen individuals with medial compartment KOA were selected randomly. Three-dimensional reconstruction software, coupled with FEA software, was employed to model PFO, allowing observation of changes in stress distribution, peak stress, and contact area of articular cartilage in femoral cartilage, tibial plateau cartilage, and meniscus before and after PFO.

Results

After PFO, significant changes in peak stress and stress distribution in the knee joint (KJ) were observed. The stress distribution shifts notably from the medial side to the lateral side. A significant reduction in peak values was observed in the medial femoral cartilage (changing from 1.91 ± 0.44 to 1.40 ± 0.14), medial meniscus (2.89 ± 0.72 to 2.05 ± 0.49), and medial tibial plateau cartilage (2.25 ± 0.65 to 1.60 ± 0.38). On the contrary, an increase in these metrics was recorded in the lateral femoral cartilage (changing from 1.10 ± 0.32 to 1.59 ± 0.30), lateral meniscus (1.82 ± 0.58 to 2.49 ± 0.60), and lateral tibial plateau cartilage (0.95 ± 0.21 to 1.40 ± 0.26). In addition, the stress distribution area of articular cartilage was reduced significantly in the medial dimension (346.25 ± 55.66 to 267.05 ± 51.05) and increased in the lateral dimension (219.35 ± 38.89 to 333.25 ± 29.90).

Conclusion

PFO demonstrates effectiveness in alleviating stress within the medial compartment of the KJ, presenting a straightforward and efficacious approach for managing medial compartment KOA.

Comparing selective and general hamstring stretching and strengthening for pain, disability, and quality of life in patients with primary knee osteoarthritis and varus deformity: A randomized clinical trial

BACKGROUND

A combination of hamstring stretching and strengthening exercises may benefit patients with knee osteoarthritis by promoting pain relief and disability improvement.

PURPOSE

The current study aimed to compare the effects of lateral hamstring strengthening and medial hamstring stretching with general hamstring stretching and general hamstring strengthening on pain, disability, and quality of life in patients with primary knee osteoarthritis and varus deformity.

METHODS

Forty patients with knee osteoarthritis were randomly assigned to two groups: a general hamstring strengthening group (14 women, 6 men) and a selective hamstring strengthening group (16 women, 4 men). In the general hamstring strengthening group, participants performed hamstring stretching and strengthening exercises broadly. In contrast, the selective hamstring strengthening group specifically targeted lateral hamstring strengthening and medial hamstring stretching. The treatment program was conducted three times a week for 4 weeks. Pain and disability levels were evaluated before and after treatment using the Knee Injury and Osteoarthritis Outcome Score (KOOS), quality of life was assessed using the Osteoarthritis Knee and Hip Quality of Life (OAKHQOL) questionnaire, and physical activity levels were determined using the Tegner activity scale.

RESULTS

Both groups demonstrated significant improvement in all outcomes except for the quality of life subscale of the KOOS questionnaire (p = .98) in the general hamstring strengthening group. However, the selective hamstring strengthening group exhibited greater improvements in symptoms (p = .02, effect size (d) = 0.92) and pain subscales (p = .01, d = 0.80) according to the KOOS questionnaire. Additionally, the pain subscale (p = .02, d = 0.79) of the OAKHQOL questionnaire exhibited greater improvements in the selective hamstring strengthening group. Tegner activity scale scores significantly improved in both groups.

CONCLUSION

Strengthening the lateral hamstring and stretching the medial hamstring muscles seem to be beneficial for reducing pain in patients with primary knee osteoarthritis and varus deformity. Attention to stabilization in frontal and horizontal planes in the knee joint might be better than simply evaluating the joint in the sagittal plane.

The Influence of Varus Deformity Correction on Clinical Outcomes: a Comparative Study of Proximal Fibular Osteotomy and High Tibial Osteotomy in Knee Osteoarthritis

Background

Proximal fibular osteotomy (PFO) and high tibial osteotomy (HTO) are two surgical options for treating varus deformities in knee osteoarthritis (KOA). While HTO provides more extensive correction, PFO offers a less invasive alternative. This study compares the radiologic and clinical outcomes of PFO and HTO to evaluate their relative efficacy.

Methods

A retrospective study was conducted with 120 patients, 60 undergoing PFO and 60 undergoing HTO, across two centers. Clinical outcomes were assessed using the Knee Society Score (KSS) and Visual Analogue Scale (VAS) for pain, while radiological outcomes were evaluated by measuring the hip-knee-ankle (HKA) angle. The complication rates were recorded, and multivariate regression analysis was performed to examine the factors influencing varus correction.

Results

Both groups showed significant improvements in pain and function, with no major differences in clinical outcomes between PFO and HTO (p > 0.05). However, HTO provided greater correction of the varus deformity (10.5 ± 1.5° vs. 3.1 ± 1.6°, p = 0.010). A higher proportion of PFO patients exhibited residual varus (> 3°) compared to those who underwent HTO (50% vs. 10%, p = 0.003). Complication rates were higher in the HTO group, with non-union and tibial hinge fractures occurring in 7% and 8% of patients, respectively.

Conclusion

PFO is a less invasive option with fewer complications but provides less varus correction than HTO. Despite this, both techniques yield comparable clinical outcomes, indicating that PFO may be a viable alternative for patients with milder deformities or higher surgical risk.

Biomechanical effects of LCWHTO vs. MOWHTO on medial meniscus posterior root repair: a finite element analysis

Whether isolated high tibial osteotomy (HTO) or HTO combined with medial meniscus posterior root (MMPR) repair is the optimal surgical treatment of MMPR tears remains controversial. This study compared the biomechanical effects of isolated HTO versus MMPR repair combined with medial open wedge HTO (MOWHTO) or lateral closed wedge HTO (LCWHTO) using finite element analysis (FEA). In this study, the MRI and CT data of the knee joint were used to create an FEA model. MOWHTO and LCWHTO simulations adjusted the mechanical axis to the Fujisawa point, with MMPR conditions simulated as intact, tear, or repaired. The ankle center was fixed and a 1000 N force was applied to the knee. In the LCWHTO models, the posterior tibial slope (PTS) decreased, whereas it increased in the MOWHTO models. Changes in the PTS following HTO influenced the stress distribution in the MMPR. HTO combined with MMPR repair showed a reduction in the maximum contact stress by 5.4-11.4% and increased contact area by 29.5-41.0% in the medial knee compartment relative to isolated HTO. This study demonstrated that MMPR repair combined with LCWHTO would be more protective against stress loading in the MMPR than MMPR repair combined with MOWHTO or isolated HTO.

Evaluation of the effect of vascularized fibula graft harvesting on coronal plane alignment and functional outcomes of the lower limb

Recent studies on fibular osteotomy for varus gonarthrosis and possible subsequent biomechanical changes have attracted increasing attention to the topic. Existing studies have focused mainly on proximal fibular osteotomy with short follow-up periods. The aim of this study was to investigate changes in the alignment of the coronal plane of the ankle and knee joints in patients who underwent vascularized fibula graft harvest (VFGH). The evaluation was based on functional outcomes and radiological measurements.In the comparison between the VFGH side and the contralateral side, no significant differences in the knee inclination (KI) or talar inclination (TI) angle, knee medial clear space (K-MCS) or ankle medial clear space (A-MCS) distance were noted. However, a significant difference in the hip knee (HKA) angle was observed between the operated and nonoperated sides (0.3° ± 1.8° and 1.5° ± 1.9°, respectively [p = 0.019]). Statistically significant differences in both the knee society score (KSS) and the AOFAS scores were found between the ipsilateral donor limb and the contralateral healthy limb. Although the contralateral healthy side had better clinical scores than the VFGH side, the outcomes of the VFGH side were still satisfactory or excellent.

Severity of knee osteoarthritis does not affect clinical outcomes following proximal fibular osteotomy - A systematic review and pooled analysis

Background & aims

Knee osteoarthritis (KOA) is a progressive degenerative disease of chronic nature. The mainstay of surgical management for KOA would be total knee arthroplasty. Joint preserving options like High Tibial Osteotomy (HTO) and Proximal Fibular Osteotomy (PFO) have been offered as an inexpensive option by knee preservation surgeons. Current literature on PFO outcomes lack of clarity for specific indications for offering PFO based on degree of severity of KOA. Therefore, this systematic review aims to critically evaluate clinical and radiological outcomes of PFO stratified by severity of KOA.

Methods

PubMed, Scopus, CINAHL and Google Scholar databases were searched. Eligible studies included those published up till August 2023, with 271 studies obtained. After duplicate removal, title-abstract screening, and a full text screen based on inclusion and exclusion criteria, 11 papers were included. 46 papers were further identified from snowballing of 7 existing systematic reviews, with 2 additional papers subsequently included.

Results

13 included articles analysed 788 knees. Our study found that indications based on KL grading of KOA do not seem to differ in terms of post-operative clinical outcomes (VAS score) and radiological measures also found that hip knee alignment was improved regardless of KL grading of KOA. Additionally, the most common post-operative complication reported was deep peroneal nerve palsy.

Conclusion

PFO is a viable knee joint preserving surgery for medial compartment KOA, however given the high risk for complications reported in the literature, surgeons should pay close attention to the neuroanatomical landmarks and techniques to avoid neurovascular injury.

Correlation Between Coronal Position Sequence of Lumbar and WOMAC Score in Knee Osteoarthritis (KOA) in Standard Standing Position

INTRODUCTION

Sagittal sequences of the spine have been shown to correlate with knee osteoarthritis (KOA), but coronal sequences and KOA have never been studied before. The study required patients to use a standard standing posture and aimed to explore the relationship between coronal position of lumbar spine and WOMAC score in KOA.

METHODS

This is a cross-sectional observational study. Data on a total of 268 patients with KOA were collected. Patients were photographed in a standard standing position and lumbar-sacrum offset distance (L-SOD) and lumbar-knee offset distance (ΔL-KOD) were calculated. Patients were then divided into different groups according to different critical values and differences were compared.

RESULTS

In the L-SOD of L1-3, WOMAC function (P = 0.021, P = 0.032, P = 0.001) and total score (P = 0.039, P = 0.034, P < 0.001) were different. In the L-SOD of L3-4, WOMAC pain score were different (P = 0.001, P = 0.032). At a cutoff of 13 mm, ΔL-KOD of L1-2 showed significant differences in pain part (P = 0.025, P = 0.039) and total score (P = 0.036, P = 0.050). There were significant differences in pain (P = 0.023, P = 0.027, P = 0.022), function (P = 0.048, P = 0.038, P = 0.047), and total score (P = 0.030, P = 0.027, P = 0.029) of L3-5. In the 18-mm cutoff group, only L1 and L2 have differences in the pain part (P = 0.050, P = 0.038).

CONCLUSION

Coronal balance of the lumbar spine is associated with knee pain and function. The pelvis plays an important role in maintaining the coronal balance. Both the lumbar spine and the knee joint should be considered when developing the surgical strategy.

How effective is proximal fibular osteotomy in redistributing joint pressures? Insights from an HTO comparative in-silico study

BACKGROUND

Knee osteoarthritis (KOA) represents a widespread degenerative condition among adults that significantly affects quality of life. This study aims to elucidate the biomechanical implications of proximal fibular osteotomy (PFO), a proposed cost-effective and straightforward intervention for KOA, comparing its effects against traditional high tibial osteotomy (HTO) through in-silico analysis.

METHODS

Using medical imaging and finite element analysis (FEA), this research quantitatively evaluates the biomechanical outcomes of a simulated PFO procedure in patients with severe medial compartment genu-varum, who have undergone surgical correction with HTO. The study focused on evaluating changes in knee joint contact pressures, stress distribution, and anatomical positioning of the center of pressure (CoP). Three models are generated for each of the five patients investigated in this study, a preoperative original condition model, an in-silico PFO based on the same original condition data, and a reversed-engineered HTO in-silico model.

RESULTS

The novel contribution of this investigation is the quantitative analysis of the impact of PFO on the biomechanics of the knee joint. The results provide mechanical evidence that PFO can effectively redistribute and homogenize joint stresses, while also repositioning the CoP towards the center of the knee, similar to what is observed post HTO. The findings propose PFO as a potentially viable and simpler alternative to conventional surgical methods for managing severe KOA, specifically in patients with medial compartment genu-varum.

CONCLUSION

This research also marks the first application of FEA that may support one of the underlying biomechanical theories of PFO, providing a foundation for future clinical and in-silico studies.

Coronal Knee Alignment and Tibial Rotation in Total Knee Arthroplasty: A Prospective Cohort Study of Patients with End-Stage Osteoarthritis

Several studies have found a relationship between the rotational anatomy of the distal femur and the overall coronal lower limb alignment in knees with osteoarthritis (OA). Less is known about the rotation of the proximal tibia, especially in the context of total knee arthroplasty (TKA), where one of the goals of the surgery is to achieve the appropriate component-to-component rotation. The aim of this study was to investigate the relationship between the coronal alignment of the lower extremity and the relative proximal tibial rotation. A prospective cohort study of patients with an end-stage OA scheduled for TKA was conducted. All patients underwent a computed tomography (CT) scan and a standing X-ray of both lower limbs. A relative femorotibial rotation was measured separately for mechanical and kinematic alignment. A statistically significant correlation was found between the tibial varus and the external tibial rotation (p < 0.001). Out of 14 knees with high tibial varus (>5°), 13 (93%) and 7 (50%) knees had >10° of femorotibial rotation for the mechanical and kinematic alignment landmarks, respectively. In order to keep the component-to-component rotation within the 10° margin, more internal rotation of the tibial component is required in knees with higher tibial varus.

Alternative Treatment of Gonarthrosis: Proximal Fibular Osteotomy

INTRODUCTION

Gonarthrosis is arthrosis of the knee joint, a chronic non-inflammatory disease manifested by progressive destruction of the intra-articular cartilage, accompanied by abnormal formation of the bones form the joint, changes in the synovial membrane and synovial fluid. Gonarthrosis is the most common type of arthrosis. Gonarthrosis can be treated conservatively and operatively. Among well-established surgical options for the treatment of medial gonarthrosis are high tibial osteotomy (HTO), unicompart-mental knee arthroplasty (UKA), and total knee arthroplasty (TKA). Proximal fibular osteotomy (PFO) or superior partial fibulectomy is a relatively recent procedure proposed to reduce knee pain in patients with medial compartment.

AIM

Our study aims to demonstrate an alternative treatment for gonarthrosis with proximal fibular osteotomy and reduced knee pain in patients with medial compartment osteoarthritis of the knee.

MATERIALS AND METHODS

At the Department of Orthopedics and Traumatology at J.Z.U "Borka Taleski" Prilep in the period from 2018 to 2021, 14 cases were treated, of which 11 were female and 3 were male. All patients were aged between 62 and 82 years with a mean age of 71.3 years. Patients had a severe degree of gonarthrosis (III/IV) according to Kellgren-Lawrence classification. Arthroscopy was performed in 2 patients. The fibula osteotomy was 7 cm away from the fibular head, with 1 cm resected bone fragment from the fibula.

RESULTS

The average duration of the surgery was 30 minutes. Patients were followed up on the 7th day, first month, 3 months and 6 months after surgery. The final evaluation of function was done after 6 months by examining the active and passive movements of the knee joint. In all 14 patients we have excellent results with pain reduction, improvement of movement and quality of life.

CONCLUSION

Proximal fibular osteotomy is an option for medial compartment osteoarthritis of the knee. Current literature is limited to small case series which report good outcomes in pain reduction, including the correction of varus deformity in medial gonarthrosis. Further studies are needed to determine the place of the PFO in the medial gonarthrosis management algorithm before it can be recommended for routine clinical use.

Severe medial osteoarthritis predicts patient dissatisfaction after proximal fibular osteotomy: a mid- to long-term follow-up study

PURPOSE

This study aimed to investigate postoperative patient satisfaction at mid- to long-term follow-up after proximal fibular osteotomy and to identify risk factors for patient dissatisfaction.

METHODS

This was a retrospective cross-sectional study that included 252 knees from 160 osteoarthritis (OA) patients who underwent proximal fibular osteotomy with a follow-up of four to eight years. Patients were categorized into a satisfied group (satisfaction score ≥ 20) or a dissatisfied group (satisfaction score < 20) based on the New Knee Society Score (New KSS). Patient demographics, preoperative pain visual analogue scale (VAS) score, preoperative Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Kellgren-Lawrence (K-L) grade, preoperative hip-knee-ankle (HKA) angle, and preoperative medial proximal tibial angle (MPTA) were compared between the two groups. Multiple logistic regression analysis was used to identify risk factors for patient dissatisfaction.

RESULTS

Of the 203 knees, 130 (64.0%) were satisfied with their results. Multiple logistic regression analysis demonstrated that severe medial OA (K-L grade = IV) was an independent risk factor for patient dissatisfaction after proximal fibular osteotomy (OR 8.334, 95% CI 3.815-18.206, P < 0.001).

CONCLUSION

Our study confirmed that proximal fibular osteotomy was a simple and effective treatment for medial OA patients, and majority of our patients obtained a higher satisfaction rate within mid- to long-term follow-up after surgery. Severe medial OA, however, was an independent risk factor for dissatisfaction.

The association between unilateral high-riding vertebral artery and atlantoaxial joint morphology: a multi-slice spiral computed tomography study of 396 patients and a finite element analysis

BACKGROUND CONTEXT

A high-riding vertebral artery (HRVA) can deviate too medially, too posteriorly, or too superiorly to allow the safe insertion of screws. However, it is unknown whether the presence of a HRVA is associated with morphological changes of the atlantoaxial joint.

PURPOSE

To investigate the association between HRVA and atlantoaxial joint morphology in patients with and without HRVA.

STUDY DESIGN

A retrospective case-control study and finite element (FE) analysis.

PATIENT SAMPLE

A total of 396 patients with cervical spondylosis underwent multi-slice spiral computed tomography (MSCT) of cervical spine at our institutions from 2020 to 2022.

OUTCOME MEASURES

A series of atlantoaxial joint morphological parameters, including C2 lateral mass settlement (C2 LMS), C1-2 sagittal joint inclination (C1-2 SI), C1-2 coronal joint inclination (C1-2 CI), atlanto-dental interval (ADI), lateral atlanto-dental interval (LADI), and C1-2 relative rotation angle (C1-2 RRA) were measured, and lateral atlantoaxial joints osteoarthritis (LAJs-OA) was recorded. The stress distribution on the C2 facet surface under different torques of flexion-extension, lateral bending, and axial rotation was analyzed by FE models. A 2-Nm moment was applied to all models to determine the range of motion (ROM).

METHODS

A total of 132 consecutive cervical spondylosis patients with unilateral HRVA were enrolled in the HRVA group, and 264 patients without HRVA matched for age and sex were enrolled in the normal (NL) group. Atlantoaxial joint morphological parameters were compared between two sides of C2 lateral mass within HRVA or NL group, and between HRVA and NL groups. A 48-year-old woman with cervical spondylosis without HRVA was selected for cervical MSCT. A three-dimensional (3D) FE intact model of the normal upper cervical spine (C0-C2) was created. We established the HRVA model by simulating atlantoaxial morphological changes of unilateral HRVA with FE method.

RESULTS

The C2 LMS was significantly smaller on the HRVA side than that on the non-HRVA side in the HRVA group, but C1-2 SI, C1-2 CI, and LADI on HRVA side were significantly larger than those on non-HRVA side. There was no significant difference between left and right sides in the NL group. The difference in C2 LMS (d-C2 LMS) between HRVA side and non-HRVA side in the HRVA group was larger than that in the NL group (P < 0.05). Meanwhile, the differences in C1-2 SI (d-C1/2 SI), C1-2 CI (d-C1/2 CI), and LADI (d-LADI) in the HRVA group were significantly larger than those in the NL group. The C1-2 RRA in the HRVA group was significantly larger than that in the NL group. Pearson correlations showed that d-C1/2 SI, d-C1/2 CI, and d-LADI were positively associated with d-C2 LMS (r=0.428, 0.649, 0.498, respectively, p<.05 for all). The incidence of LAJs-OA in the HRVA group (27.3%) was significantly larger than that in the NL group (11.7%). Compared with the normal model, the ROM of C1-2 segment declined in all postures of the HRVA FE model. We found a larger distribution of stress on the C2 lateral mass surface of the HRVA side under different moment conditions.

CONCLUSIONS

We suggest that HRVA affects the integrity of the C2 lateral mass. This change in patients with unilateral HRVA is associated with the nonuniform settlement of the lateral mass and an increase in the lateral mass inclination, which may further affect the degeneration of the atlantoaxial joint because of the stress concentration on the C2 lateral mass surface.

Novel ideas for the comprehensive evaluation of varus knee osteoarthritis: radiological measurements of the morphology of the lateral knee joint

BACKGROUND

The lateral anatomical and morphological characteristics of knees with varus knee osteoarthritis (OA) have not received sufficient attention. This study used several radiological parameters to describe the morphological characteristics of the lateral knee with OA to determine whether there are relationships between varus knee OA and parameters such as lateral plateau widening (LPW), proximal fibula curvature (PFC), and fibula height (FH).

METHODS

The study retrospectively analyzed 1072 subjects who underwent standard radiography for diagnosing or evaluating symptomatic knee joint disease. The 163 Kellgren and Lawrence (K-L) grades 0 and I knees were categorized into the no-knee-OA group, and the 909 K-L grades II-IV knees were classified into the knee-OA group. Medial proximal tibial angle, joint line convergence angle, hip-knee-ankle angle, LPW, PFC, and FH were measured. T tests and chi-square tests were used to compare each index between the two groups. Binary logistic regression was performed to examine the correlation between indexes and knee OA occurrence. Ordinal logistic analysis, principal component analysis, and multivariable linear regression analysis were performed to examine the correlations between the three lateral parameters and K-L grades and the degree of varus deformity.

RESULTS

LPW and PFC were significantly greater and FH was significantly smaller in the knee-OA group than in the no-knee-OA group. LPW, PFC, and FH were correlated with knee OA occurrence. One principal component, named the comprehensive principal component score of varus deformity, was extracted from the three indexes, and the total variance of the principal component interpretation was 76.60%. Ordinal logistics and multivariable linear regression analysis showed that, after adjusting for age and BMI, LPW and PFC were positively correlated with K-L grading and varus deformity. FH was significantly and negatively correlated with K-L grading and varus deformity (all P < 0.05).

CONCLUSIONS

Regular morphological changes take place in the lateral knee with varus OA, including lateral dislocation of the tibial plateau, proximal fibula bending, and upward movement of the fibular head. Changes in LPW, PFC, and FH could enable a more comprehensive assessment of varus knee OA occurrence, severity, and deformity. Level of evidence Retrospective Study Level III.

Anatomical Imaging Study on Uneven Settlement of the Proximal Tibia

OBJECTIVE

Uneven settlement of the proximal tibia significantly contributes to the onset and progression of medial compartment knee OA; however, the specific location and variations of proximal tibial deformity remain unclear. Therefore, this study aimed to explore the effects of the anatomic morphology of different tibial regions on proximal tibial vara and proximal tibial microstructural changes with age in both sexes to reveal the pattern of uneven settlement of the proximal tibia.

METHODS

In this retrospective study, we reviewed the radiographs of 414 patients (789 legs) between May and September 2021. The medial proximal tibial angle (MPTA) and four anatomic angles of the tibia (i.e., the tibial plateau-epiphyseal line [PT-EL] angle, epiphyseal line-tibial platform [EL-PF] angle, epiphyseal axis inclination angle [EAIA], and subepiphyseal axis inclination angle [SAIA]) were measured. The effect of each angle on MPTA and their changes with age in both sexes were investigated using Pearson's correlation coefficient and multiple linear regression.

RESULTS

In females, PT-EL angle, EL-PF angle, and SAIA negatively correlated with MPTA (r = -0.325, -0.246, and -0.502; p < 0.05), and EAIA positively correlated with MPTA (r = 0.099, p < 0.05). Regression analysis showed that the correlations between MPTA and PT-EL angle, EL-PF angle, and SAIA were significant (β = -1.003, -0.013, and -0.971; adjusted R2  = 0.979). Furthermore, MPTA negatively correlated with age (r = -0.202, p < 0.05); PT-EL angle and EAIA positively correlated with age (r = 0.237 and 0.142, p < 0.05). Regression analysis showed that only the correlation between PT-EL angle and age was significant (β = 5.635, p < 0.05). In males, PT-EL angle, EL-PF angle, and SAIA negatively correlated with MPTA (r = -0.270, -0.267, and -0.533; p < 0.05), and EAIA positively correlated with MPTA (r = 0.135, p < 0.05). Regression analysis showed that the correlations between MPTA and PT-EL angle, EL-PF angle, and SAIA were significant (β = -0.992, -0.017, and -0.958; adjusted R2  = 0.970). However, there was no significant correlation between age and any of the measured angles (p > 0.05).

CONCLUSIONS

Proximal tibial vara is affected by the anatomic morphology of the epiphyseal and subepiphyseal regions. In females, the uneven settlement of the epiphysis progresses with age and may be responsible for dynamic varus deformity of the proximal tibia.

Changes in the Tibial Strain After Proximal Fibular Osteotomy: A Biomechanical Cadaveric Study

Total knee arthroplasty surgery is an increasingly common procedure for the treatment of uni- and tricompartmental knee osteoarthritis, particularly in advanced stages and in the older population. Its usage is being extended to younger patients, where implant longevity is of concern. In the younger age group, especially with early disease, other options merit consideration. On the other hand, it may not be possible for elderly patients with medical comorbidities to undergo joint replacement surgery. Proximal fibular osteotomy (PFO) has recently been advocated to treat medial knee osteoarthritis. Although there have been clinical reports showing promising outcomes, the biomechanical basis of this procedure is still unclear. We performed a cadaveric study to investigate the effect of PFO on proximal tibial strain. Eight unpaired cadaveric lower limb specimens were loaded in compression at 2 times body weight. Strain gauges were mounted on various sites on the proximal tibia and fibula. After PFO, there was a significant increase in the lateral tibial strain adjacent to the proximal tibiofibular joint (P<.05). There was moderate effect size reduction in the anteromedial tibial strain as well as moderate effect size increase in the posterior tibial strain. The strain reduction seen at the anteromedial tibia can offer a possible explanation for symptomatic relief after PFO. However, the increase in the lateral and posterior tibial strain raises concern about long-term accelerated wear in these regions. [Orthopedics. 2022;45(5):314-319.].

Medial tibial plateau sustaining higher physiological stress than the lateral plateau: based on 3D printing and finite element method

Background

Medial compartment knee osteoarthritis (KOA) accounts for most KOA cases, and increased trabecular bone volume fraction (BV/TV) is one of the pathological changes in the tibial plateau of KOA. How BV/TV changes before and after the menopause and its effects on medial compartment KOA are yet to be clarified.

Methods

Twenty femurs from twenty 12-week-old rats were included. The operated group underwent ovariectomy (to represent the osteoporosis condition), called the O group, and the non-operated group was the normal control, called the N group. Micro-CT scans of the femoral condyles were acquired 12 weeks after the surgery, and the volume of interest (VOI) of medial-, inter-, and lateral-condyle trabeculae were three-dimensional (3D) printed for uniaxial compression mechanical test and simulated by the finite element (FE) method.

Results

The results demonstrated that the O group indicated poorer trabecular architecture than the N group in three parts of the femoral condyle, especially in the intercondyle. Within the group, the BV/TV, trabecular thickness (Tb.Th), and trabecular number (Tb.N) ratios between the medial and lateral condyles were greater than 1 in both N and O groups. The medial condyle trabeculae's mechanical properties were higher than those of the lateral condyle, and this superiority appears to be broadened under osteoporotic conditions. FE modelling well reproduced these mechanical differentiations.

Conclusions

According to Wolff's law, the higher BV/TV and mechanical properties of the medial femoral condyle may be due to inherent imbalanced loading on the knee component. Alterations in BV/TV and their corresponding mechanical properties may accompany KOA.

Relationship between the height of fibular head and the incidence and severity of knee osteoarthritis

The purpose of this study was to investigate the correlation between fibular head height and the incidence and severity of osteoarthritis associated with varus knee deformity. The fibular head height, joint line convergence angle (JLCA) and medial proximal tibial angle (MPTA) were measured in a three-dimensional model. Ordinal multivariate logistic regression was used to analyze the correlation between fibular head height and Kellgren–Lawrence (K–L) grade. Pearson correlation was used to analyze the correlation between fibular head height and K–L grade. A total of 232 patients (232 knees) were finally included in the study. There were significant differences in JLCA and hip–knee–ankle angle (P < 0.05), and both JLCA and hip–knee–ankle angle increased with severe aggravation of K–L grade. Both fibular head height and MPTA decreased as the K–L grade was severely aggravated. There was a significant negative correlation between K–L grade and fibular head height (r = −0.812, P < 0.001). Furthermore, there was a significant negative correlation between fibular head height and hip–knee–ankle angle (r = −0.7905, P < 0.001). In addition to body mass index, fibular head height is a risk factor for the pathogenesis of osteoarthritis associated with varus knee deformity; the smaller the fibular head height, the more severe the degree of varus deformity.

Proximal Fibular Osteotomy for Medial Joint Osteoarthritis of the Knee: A Prospective Cohort Study

Background and objective Osteoarthritis (OA) is a polyarticular disease that most commonly afflicts the knee joint. Established operative treatment options for medial joint OA of the knee include high tibial osteotomy, unicompartmental knee arthroplasty, and total knee arthroplasty. Proximal fibular osteotomy (PFO) is a relatively new procedure for treating medial joint OA of the knee. The objective of this study was to describe the functional and radiological outcomes at one year in patients undergoing PFO for medial joint OA of the knee. Materials and methods The study included 21 patients with medial joint OA of the knee who underwent PFO. Visual analog scale (VAS) score, medial to lateral knee joint space ratio (ML ratio), Kellgren-Lawrence (KL) grade, and the American Knee Society Score (AKSS) (clinical and functional) were recorded preoperatively. VAS score, ML ratio, and AKSS (clinical and functional) were documented again at the three-month and one-year follow-ups. Results The mean age of the patients was 58.85 ±6.94 years; 12 (57.1%) were female and nine (42.9%) were males. The mean VAS score for pain decreased from 7.86 ±0.66 at baseline to 5.14 ±1.15 at three months (p<0.001) and 3.78 ±1.26 at one year (p<0.001). The mean clinical AKSS was 56.49 ±6.95 at baseline, which increased to 63.41 ±6.20 at three months (p<0.001) and 72.71 ±9.87 at one year (p<0.001). The mean functional AKSS at baseline was 48.24 ±14.31, which increased to 60.10 ±14.81 at three months (p<0.001) and 71.46 ±15.18 at one year (p<0.001). The mean ML ratio at baseline was 0.33 ±0.19, which increased to 0.41 ±0.20 at three months (p<0.01) and 0.51 ±0.22 at one year (p<0.001). Conclusion In patients who undergo PFO for OA of the knee, improvements in VAS score for pain, AKSS (functional and clinical), and ML ratio were observed to be maintained for a period of one year postoperatively.

Association Between Clinical Symptoms and Radiographic Features in Late-Stage Knee Osteoarthritis Using a New Radiographic Parameter

OBJECTIVE

In this study, we proposed a new radiographic parameter, the plateau attrition index (PAI), and the PAI grades (PAIs) to explore the relationship between subchondral attrition of the tibial plateau and symptoms of knee osteoarthritis (OA) in patients with late-stage knee osteoarthritis.

METHOD

One hundred nineteen patients with late-stage knee osteoarthritis were enrolled. The Kellgren and Lawrence (K/L) grades and hip-knee-ankle (HKA) angle were used to characterize the radiographic features of knee OA. The bone attrition of the tibial plateau was determined by the PAI and PAIs. The symptoms of knee OA were assessed by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), which is composed of the WOMAC pain (WOMP), WOMAC stiffness (WOMS), and WOMAC function (WOMF) subscores. WOMAC pain scores were divided into non-weight-bearing pain (NWBP) and weight-bearing pain (WBP) subcategories. The Pearson correlation coefficient was used to determine the relationship between the PAI, HKA angle, and WOMAC scores. The Spearman rank correlation coefficient was used to evaluate the correlation between the WOMAC score and the PAIs and K/L grades.

RESULTS

The distribution of the WOMAC scores according to the PAIs was significant (P < .01). A positive correlation was identified between the PAI and the WOMAC, WOMP, WOMF and WBP scores (r = 0.29, 0.34, 0.26 and 0.34, P < .01, respectively). In addition, the PAIs was also significantly correlated with the WOMAC, WOMP, WOMF, and WBP scores (r = 0.37, 0.38, 0.35 and 0.44, P < .01, respectively).

CONCLUSIONS

The attrition of tibial subchondral bone determined by the new parameter, the plateau attrition index, was correlated with symptoms, especially weight-bearing pain in late-stage knee OA.

Osteotomy Around the Knee: The Surgical Treatment of Osteoarthritis

Osteoarthritis causes joint pain and functional disorder, of which knee osteoarthritis is the most common. Nowadays, clinically effective treatments mainly include conservative treatment, arthroplasty, and osteotomy. However, conservative treatment only offers symptomatic relief and arthroplasty is limited to the patients with a moderate to severe degree of osteoarthritis. For relatively young patients who require greater knee preservation, a surgical treatment with low operation trauma and revision rate is needed. Osteotomy around the knee, based on the notion of “knee preservation,” has been chosen as an alternative surgical treatment. Cutting and realigning the bones corrects the mechanical line of lower limb force bearing. As such, osteotomy around the knee retains normal anatomical structure and obtains good functional recovery of the knee joint. The techniques of osteotomy around the knee includes anti‐varus deformity and anti‐valgus deformity osteotomy, aiming to reallocate the force bearing in the compartment of the knee joint. By choosing the surgical section of the lower limbs, the osteotomy around the knee can achieve the correction of mechanical axis, such as the high tibial osteotomy (HTO), proximal fibular osteotomy (PFO), and distal femur osteotomy (DFO). Numerous modified techniques have been developed to meet the demands of patients based on traditional methods. These modified osteotomy have their own advantages and indications. This paper aims to guide clinical treatment by reviewing different types of osteotomies, and their effects, that have been studied and applied widely in clinical practices.

Open-Wedge HTO with Absorbable β-TCP/PLGA Spacer Implantation and Proximal Fibular Osteotomy for Medial Compartmental Knee Osteoarthritis: New Technique Presentation

PURPOSE

The purpose of this study was to present a new absorbable spacer for medial compartmental knee osteoarthritis (OA). The functional and radiographic results of patients treated with the novel surgical technique were also evaluated to investigate its clinical feasibility.

METHODS

Patients with medial compartmental knee OA who underwent open-wedge high tibial osteotomy (HTO) with absorbable β-TCP/PLGA [30% beta-tricalcium phosphate and 70% poly (lactic-co-glycolic acid)] spacer implantation and proximal fibular osteotomy from January 2016 to February 2017 were retrospectively analyzed. The operation time, blood loss, and relevant complications were reviewed. The femorotibial angle (FTA), varus angle (VA), joint line convergence angle (JLCA), American Knee Society Score (KSS), and visual analog scale (VAS) score were recorded preoperatively and at the final follow-up, respectively.

RESULTS

At the final follow-up, the mean FTA and JLCA were 179.85° ± 4.34° and 2.44° ± 1.26°, respectively, which were smaller than the preoperative values (182.94° ± 3.86° and 4.12° ± 1.65°, respectively; both p < 0.001). The final VA and VAS score were lower than those measured preoperatively (both p < 0.001). The clinical and functional KSSs at the final follow-up were higher than the preoperative scores (p < 0.001).

CONCLUSIONS

This novel absorbable spacer could provide adequate stability for the tibial osteotomy gap, at a lower cost than a traditional plate. With the use of this spacer as an osteoinductive and biodegradable device, secondary surgery for fixation removal could be avoided. The novel surgical technique could improve both the radiographic appearance and the function of the knee in patients with knee OA.

Anatomical basis of the support of fibula to tibial plateau and its clinical significance

Background

The fibula is only indirectly involved in the composition of the human knee joint and has therefore been neglected in the research on knee osteoarthritis. Nonuniform settlement of the proximal tibia plateau is clinically defined as when the height of the medial tibial plateau is lower than that of the lateral side in medial compartment knee osteoarthritis (KOA). The non-uniform settlement of the proximal tibia plateau may be caused by fibular support on the lateral side. Orthopedic surgeons practice partial fibulectomy based on the clinical manifestation of nonuniform settlement, and this technique has been shown to reduce pain and improve function in patients with medial compartment KOA. However, this hypothesis of the mechanism of nonuniform settlement lacks an anatomical basis.

Methods

The P45 polyester plastination technique was used to prepare sections of the proximal tibiofibular joint to investigate the distribution of the bone trabeculae in the region of the lateral tibial plateau.

Results

There was uneven distribution of trabeculae in the lateral condyle of the tibia and the head and neck of the fibula. The fibula and the posterolateral cortex of the shaft of the tibia united to form an arch beam via the tibiofibular joint. Many thick, dense trabeculae were present in a longitudinal direction above the tibiofibular arch.

Conclusions

The fibula supports the lateral tibial plateau, and the trabeculae were concentrated above the tibiofibular arch.

Comparison of Clinical and Radiological Outcomes Between Upper Fibular Curvature and Non-Curvature with Medial Knee Osteoarthritis Following Proximal Fibular Osteotomy: A Retrospective Cohort Study with Minimum 2-Year Follow-up

Objective

To evaluate and compare the clinical and radiographic outcomes of proximal fibular osteotomy (PFO) in treating medial knee osteoarthritis (KOA) patients with upper fibular curvature and non‐curvature.

Methods

A retrospective cohort study was performed. From January 2016 to January 2017, a total of 51 patients (nine males and 42 females) at a mean age of 63.7 years (range 48–79 years) with medial KOA who underwent PFO procedure at the Third Hospital of Hebei Medical University were included in the study. The patients were divided into the two groups, namely curvature group (28 patients, six males and 22 females, aged 62.6 ± 7.7 years) and non‐curvature group (23 patients, three males and 20 females, aged 64.5 ± 7.6 years). Perioperative parameters and Kellgren‐Lawrence classification were recorded and analyzed in the two groups, respectively. All patients were followed up at 1, 3, 6, and 12 months at the first year of post‐operation, and then every 6 months from the second year of post‐operation. A telephone survey with standard questionnaire survey, including Visual Analog Scale (VAS) score and Hospital for Special Surgery (HSS) scoring system, was used to evaluate postoperative clinical outcomes. Radiological results were assessed using the femorotibial angle (FTA), hip‐knee‐ankle angle (HKA), and settlement value of medial tibial platform (MTP) in the two groups.

Results

The average follow‐up periods of the curvature group and the non‐curvature group were 34.8 ± 6.1 and 33.9 ± 5.4 months, respectively. There were no significant differences between the two groups of demographic data in terms of number of patients, age, body mass index (BMI), gender, KOA side, and Kellgren‐Lawrence classification (P > 0.05). The VAS scores of the curvature group and non‐curvature group were (3.53 ± 1.62 vs 3.68 ± 1.43 at 1 month, 3.46 ± 0.79 vs 3.57 ± 0.66 at 3 months, and 2.43 ± 0.88 vs 2.83 ± 0.94 at 6 months, both P > 0.05), while significant differences were found from 12 months post‐operation (1.54 ± 0.72 vs 2.03 ± 0.85 at 12 months, and 1.04 ± 0.69 vs 1.74 ± 0.75 at 24 months, both P < 0.05). The HSS scores of the curvature group and non‐curvature group were (79.67 ± 5.14 vs 78.25 ± 6.37 at 1 month, 84.65 ± 3.76 vs 83.18 ± 3.64 at 3 months, and 86.27 ± 3.13 vs 85.49 ± 3.25 at 6 months, both P > 0.05), while significant differences were found from 12 months post‐operation (90.64 ± 4.32 vs 87.71 ± 5.63 at 12 months, and 92.93 ± 2.07 vs 90.06 ± 2.08 at 24 months, both P < 0.05). In addition, the FTA and settlement value of the curvature group were lower than the non‐curvature group (177.18 ± 1.52 vs 178.35 ± 1.86, and 5.29 ± 1.74 vs 6.49 ± 2.09, both P < 0.05) while the HKA were higher than the non‐curvature group (175.32 ± 2.34 vs 173.83 ± 2.64, P < 0.05) at the final follow‐up.

Conclusions

Medial KOA patients with upper fibular curvature is an optimal surgical indication for PFO surgery, with the advantages of pain relief, better functional recovery, and alignment correction.

Associations Between Periosteal Reaction of Proximal Tibial and Medial Compartment Knee Osteoarthritis

Objective

To evaluate and analyze the potential relationship between periosteal reaction and medial compartment knee osteoarthritis (KOA), and to assess the independent risk factors for the development of periosteal reaction associated with medial compartment KOA.

Methods

This is a retrospective comparative study. From January 2019 to December 2019 at the Third Hospital of Hebei Medical University, a total of 363 patients (726 knees) with medial compartment KOA were enrolled in this study according to our inclusion and exclusion criteria, including 91 males and 272 females, with an mean age of 57.9 ± 12.8 years (range, 18–82 years). Among these patients, 206 patients (412 knees) were allocated to the periosteal reaction group (44 males and 162 females) and 157 patients (314 knees) were allocated to the non‐periosteal reaction group (47 males and 110 females). The classification of KOA severity was based on Kellgren and Lawrence (K‐L) grading system. The malalignment of the lower extremities in coronal plane was evaluated as medial proximal tibial angle (MPTA), hip‐knee‐ankle angle (HKA), and lateral distal femoral angle (LDFA). Patients demographics and radiographic parameters were recorded in the two groups. Intra‐observer and inter‐observer reliabilities of all radiological measurements were analyzed by intraclass correlation coefficients (ICCs). Univariate analyses were conducted for comparison of differences with continuous variables between patients with periosteal reaction and without periosteal reaction. Multivariate logistical regression analysis was performed to determine the independent risk factors of radiographic parameters for periosteal reaction.

Results

The overall incidence of periosteal reaction associated with medial compartment KOA was 56.7%. Furthermore, we observed that the incidence of periosteal reaction significantly increased with age and correlated with K‐L grade progression (P < 0.05). There was a statistically significant difference between the two groups. In the multivariate logistical regression analysis, HKA and JLCA were identified as independent risk factors of the development of periosteal reaction in patients with medial compartment KOA (odds ratio [OR], 0.594; 95% confidence interval [CI] 0.544–0.648; P < 0.05; OR, 0.851; 95% confidence interval CI 0.737–0.983; P < 0.05; respectively), with other radiographic parameters including MTPA (OR 0.959; 95% CI 0.511–0.648; P > 0.05), LDFA (OR 0.990; 95% CI 0.899–1.089; P > 0.05), and JSW (OR 1.005; 95% CI 0.865–1.167; P > 0.05).

Conclusions

In this retrospective study, patients with lower HKA and higher JLCA were identified as independent risk factors for the development of periosteal reaction, which occurred most commonly adjacent to the lateral of proximal tibia diaphysis, and thus we concluded that periosteal reaction may be an anatomical adaptation for medial compartment KOA based upon these results.

Proximal fibular osteotomy: Systematic review on its outcomes

BACKGROUND

The morbidity and burden of knee osteoarthritis affecting millions of lives worldwide has created a constant pursuit in finding the ideal treatment for knee osteoarthritis. There has been a paradigm shift in the surgical treatment of osteoarthritis ever since the initial description of Volkmann’s tibial osteotomy. This review focuses on one such recent procedure, the proximal fibular osteotomy (PFO) for medial compartment knee osteoarthritis. This review encompasses the history, evidence, risk factors, outcomes and technical considerations of PFO.

AIM

To understand the evidence and its techniques, and whether this could be an alternative solution to the problem of knee osteoarthritis in the developing world.

METHODS

The phrases “proximal fibular osteotomy” and “knee osteoarthritis” were searched (date of search December 20, 2019) on PubMed to identify articles evaluating the biomechanical and clinical outcomes of PFO in patients with knee osteoarthritis. A total of 258 were retrieved. After reviewing the summary of the texts, 22 articles written in English were marked for abstract review. Articles that were case studies or cadaver experiments were excluded. The abstracts of the remaining articles were read, and only those that focused on the history, outcomes of case studies and technical considerations of PFO were included in the review. A total of 12 articles were included in this review.

RESULTS

At least six studies reported improvement in the visual analogue scale(VAS) from the average preoperative VAS score [6.32, 95% confidence interval (CI) = (4.05, 8.59)] to average postoperative VAS score [1.23, 95%CI: (-1.20, 3.71)], which was statistically significant. Similarly, the American Knee Society Score (KSS) functional score improved from an average preoperative KSS functional score [43.11, 95%CI: (37.83, 48.38)] to postoperative KSS functional score [66.145, 95%CI: (61.94, 70.35)], which was statistically significant. The femorotibial angle improved by around 7^º, and the hip knee ankle angle improved by around 6^º.

CONCLUSION

With the existing data, it seems that PFO is a viable option for treating medial joint osteoarthritis in selected patients. Long term outcome studies and progression of disease pathology are some of the important parameters that need to be addressed by use of multicenter randomized controlled trials.

Correction surgery for adult spinal deformity improves not only spinopelvic alignment but also the three-dimensional alignment of the lower extremities

BACKGROUND

It is well known that correction surgery for adult spinal deformity (ASD) improves sagittal and coronal spinopelvic alignment, but the surgery effect on lower extremities (LE) is not well clarified. The aim of this study was to test the hypothesis that LE alignment also improves following spinopelvic correction surgery for ASD as a function of compensatory mechanism, and to clarify an effect of the severity of knee osteoarthritis (OA) on the improvement.

METHODS

We retrospectively evaluated spinopelvic alignment, hip knee ankle angle (HKA), knee flexion angle (KF), and severity of the knee OA in thirty-nine patients with ASD before, two weeks and three months after the surgery. The grade of knee OA was evaluated by Kellgren Lawrence grading, and classified grade 0 to 2 into mild, and 3, 4 into severe OA. All the values were compared by paired t test or Wilcoxon signed rank test with significant p value of <0.05.

RESULTS

Following the surgery, not only spinopelvic, but also bilateral HKA and KF were significantly improved. HKA in mild OA side was more normalized compared to that in severe side. Although KF of both bilateral mild and bilateral severe OA groups improved, the improvement of mild group was more significant.

CONCLUSION

The 3D alignment of LE improved following spinopelvic correction surgery. The improvement was inadequate in cases with severe knee OA.

Proximal Fibular Osteotomy: Biomechanics, Indications, Technique, and Results

The evidence base is growing regarding proximal fibular osteotomy. Most studies show that the pain relief and improvement in terms of radiology is statistically significant. More understandable biomechanical theories explaining this improvement are appearing. Because it has a low complication rate and is relatively easy to execute, proximal fibular osteotomy should definitely be considered in any algorithm for the treatment of medial compartment osteoarthritis of the knee. [Orthopedics. 2020;43(6):e627-e631.].

Proximal Fibular Osteotomy: Is it Really an Option for Medial Compartmental Osteoarthritis Knee? Our Experience at Tertiary Centre

INTRODUCTION

The medial compartment is commonly involved in age-related osteoarthritis knee because weight-bearing axis passes close to the medial condyle and its large surface area. Various treatments have been proposed ranging from conservative to total knee arthroplasty which is an expensive and complex treatment. Recently, proximal fibular osteotomy (PFO) for medial compartment knee osteoarthritis became popular as a treatment modality. Although, the mechanism of PFO is not clear. So, we conducted a prospective study to assess the clinico-radiological outcome of proximal fibular osteotomy in medial compartment osteoarthritis knee.

MATERIALS AND METHODS

We conducted a prospective study from November 2017 to November 2019 on 32 (47 knees) patients with degenerative medial compartmental osteoarthritis knee, varus deformity < 15 and Kellgren and Lawrence grade II and grade III (K-L Grade). We recorded the visual analogue score (VAS) and knee society score (KSS) pre-operatively and post-operatively of all patients.  We got weight bearing anterio-posterior and lateral radiograph of knee done. We assessed joint space ratio and lateral tibio-femoral angle (FTA) pre-operatively, post-operatively and at each follow-up.

RESULTS

Mean age was 48.4 (35-65) years and the mean follow-up was 18 months. Mean duration for unilateral PFO was 37 min and for bilateral, 55 min. The VAS was improved from 7.33 ± 0.72 to 7.13 ± 1.64 at 3 months and remained the same at final follow-up (p > 0.05). The mean pre-operative clinical and functional KSS was statistical insignificantly improved at 3 months and final follow-up (p > 0.05). The mean pre-operative lateral and mean pre-operative joint space ratio was also improved statistically insignificant (p > 0.05). Extensor hallucis longus (EHL) weakness was documented in five knees (10.6%) and paraesthesia was documented in seven (14.8%) knees.

CONCLUSION

Although, PFO is a simple, less invasive and affordable procedure, we could not reproduce the favourable results in medial compartmental osteoarthritis knee. This procedure is also associated with reversible but noticeable complications. So, we would not consider PFO as an alternative option in the treatment of medial compartmental osteoarthritis knee.

Age-related dynamic deformation of the femoral shaft and associated osteoporotic factors: a retrospective study in Chinese adults

Dynamic skeletal deformation with ageing showed important signs of degenerative and osteoporotic diseases. We found that both femoral bowing and cortical thickness were correlated with ageing in a Chinese population. Further, femoral cortical index, an osteoporotic indicator, was negatively correlated with femoral bowing angle. Hence, more attention should be paid to these femoral morphological changes to avoid fragility fractures and failed internal fixation.

PURPOSE

The purpose of this study was to determine whether morphological parameters of the femoral shaft are in age-related deformation and identify correlations between parameters of femoral cortical thickness and femoral shaft bowing.

METHODS

One hundred twenty patients (mean 50 years, range 18~104 years) who had received standard long-standing anteroposterior and femoral lateral radiographs from October 2016 to October 2019 were included in this retrospective study. The sagittal femoral bowing angle (sFBA), sagittal femoral cortical index (sFCI), coronal femoral bowing angle (cFBA), and coronal femoral cortical index (cFCI) were measured by two orthopaedists separately. All the participants' demographic data, including age, sex, body laterality, height, and weight, were collected. The Student's t test, Mann-Whitney U test, two-way ANOVA, Pearson correlation, and multiple linear regression were used in the statistical analysis.

RESULTS

The mean age of the male and female participants was 46.95 ± 15.25 and 52.22 ± 15.61 years, respectively. Two-way ANOVA revealed that females had a significantly lower sFCI than males at the right side (P < 0.05). There were no significant interactions between sex or body laterality and the sFBA, cFBA, sFCI, and cFCI groups (P > 0.05). Pearson correlation revealed that sFCI was strongly correlated with sFBA (r = - 0.535, P < 0.05) and cFBA (r = - 0.535, P < 0.05). Multiple linear regression analysis demonstrated that both age (β = 0.304 and 0.308 respectively) and sFCI (β = - 0.322 and - 0.414 respectively) were two independent predictors associated with sFBA and cFBA respectively.

CONCLUSIONS

The femoral shaft bowing of the Chinese population was positively correlated with ageing, whereas the sagittal femoral cortical thickness negatively correlated with ageing. A high FBA occurred in femoral shafts with a low sFCI, which revealed that femoral shaft bowing was associated with femoral cortical thickness. During femur-related surgery in older patients, more attention should be paid to these femoral morphological changes.

Proximal Fibular Osteotomy for Medial Compartment Knee Osteoarthritis: Is It Worth?

BACKGROUND

Osteoarthritis of knee is one of the important causes of knee pain in elderly patients and is a debilitating disease. It often leads to varus deformity of knee. Many treatment options are available for this progressive knee joint disorder. Proximal fibular osteotomy (PFO) is a novel yet simple procedure used to alleviate the symptoms of medial compartment knee osteoarthritis. The present study was undertaken to evaluate whether this procedure improves the symptoms, functions and limb alignment in patients with medial compartment knee osteoarthritis.

METHODS

Following approval by the Institutional Review Board, this prospective study included 42 cases (56 knees) with Kellgren-Lawrence grade II and III medial compartment knee osteoarthritis and underwent proximal fibular osteotomy. Clinical assessment was done by visual analogue scale (VAS) score and The Western Ontario and McMaster universities osteoarthritis Index (WOMAC) score pre-operatively and at 3, 6 and 12 months follow-up for pain and functional improvement. Radiological assessment was done by measuring femoro-tibial angles (FTA) pre-operatively and at 1 year follow-up.

RESULTS

The mean age was 58.30 years. There were 30 females and 12 males. The preoperative mean WOMAC score was 87.3, at 3 months follow-up it was 29.4 this was significantly better (p < 0.05) but the improvement was not significant at subsequent follow-up visits. Similarly the VAS scores also showed significant improvement at 3 months, but not at 6 and 12 months follow-up. There was no significant improvement in the femoro-tibial angle (FTA) at 1 year follow-up.

CONCLUSION

The study highlights that both the VAS scores and WOMAC scores were significantly better at 3 months after surgery. However these did not show any significant improvement at 6 and 12 months. It does not change the alignment of knee at one year follow-up. The authors conclude that proximal fibular osteotomy provides only short-term relief in patients of medial compartment knee osteo-arthritis.

Relationships between Morphological Changes of Lower Limbs and Gender During Medial Compartment Knee Osteoarthritis

Objectives

To evaluate the dynamic changes of key morphology indicators of the lower extremities in the coronal plane with progressing medial compartment knee osteoarthritis (KOA) with an emphasis on gender‐dependent regional differences.

Methods

The radiographs of patients with non‐traumatic knee pain and varying degrees of genu varus were reviewed. Radiographs were studied in 1538 lower limbs of 883 consecutive patients who visited our hospital from January to July 2017; all patients had long‐standing anteroposterior image‐splicing radiographs taken of their lower limbs. Morphological indicators of bones and joints that can change the alignment of lower limbs or reflect cartilage wear and soft‐tissue relaxation were selected and measured with the help of picture archiving and communication systems. After comparing the data of different genders, the data of males and females was separated into three age groups, <40 years, 40–60 years, >60 years respectively, and then compared among age groups using the Kruskal‐Wallis and Mann–Whitney U tests. Scatterplots of age and all the measurements were drawn to determine the strength of the relations. The Pearson correlation test was performed to reveal correlations of measurements and age.

Results

Femoral bowing angle (FBA) and joint line convergence angle (JLCA) have obvious differences between different genders (P = 0.001, 0.000, respectively). This suggests that females have greater femoral curvature and joint space angle than males. Significant differences were found in hip‐knee‐ankle angle (HKA), FBA, distal femoral valgus resection angle (DFVRA), medial proximal tibial angle (MPTA), JLCA, and minimum joint space width (min‐JSW) by age groups in females (P = 0.000, 0.000, 0.000, 0.000, 0.003, 0.002, respectively). The difference of mechanical medial distal femoral angle (mMDFA) was significant with P values less than 0.05 deemed significant (P = 0.030). Significant correlations were found between age and all measurements (r = −0.166, 0.253, 0.270, −0.147, 0.089, −0.105, −0.076, respectively, P < 0.01). Whereas, the difference in min‐JSW by age group was the only significant one in males (P = 0.001), and no significant correlation was found between age and measurements (r = −0.107, 0.041, 0.134, −0.067, 0.079, −0.134, −0.098, respectively, P > 0.01).

Conclusions

As KOA progressed, both dynamic deformation of lower extremities and degeneration of articular cartilage could be found in females, while no obvious dynamic deformations were found in males. Dynamic deformation of lower extremities was the important feature and the major causative factor of KOA in females.

Proximal fibular osteotomy alleviates medial compartment knee osteoarthritis in a mouse model

PURPOSE

The purpose of this study was to establish a mouse model of proximal fibular osteotomy (PFO), and to determine if PFO could delay degeneration of the medial compartment of the knee joint in a mouse model.

METHODS

An animal model of destabilization of the medial meniscus (DMM) was used to induce post-traumatic knee osteoarthritis (OA). PFO was performed to examine the effectiveness of PFO on protection against medial compartment knee OA. Micro-CT was used to observe osteosclerosis development in the subchondral bone, and Safranin O-fast green staining was used to evaluate the progression of articular cartilage destruction. The condylar-plateau angle (CPA) and anatomical femorotibial angle (aFTA) were measured to determine whether knee alignment was changed after PFO.

RESULTS

PFO treatment could decrease osteophyte formation and osteosclerosis development in the subchondral bone, as observed by micro-CT. The value of the ratio of trabecular bone volume to total volume (BV/TV) of DMM+PFO group was lower than that of DMM group. PFO also inhibited the progression of articular cartilage destruction. DMM + PFO group displayed decreased maximal and summed OA scores, as compared with DMM group. Moreover, the change of knee alignment was reduced by PFO, which might be the mechanism of PFO alleviating medial compartment knee OA.

CONCLUSION

Our results indicated that PFO could alleviate medial compartment knee OA in a mouse model.

Dynamic deformation of femur during medial compartment knee osteoarthritis

OBJECTIVES

The aim of this study was to evaluate the morphological changes of the femur in the coronal plane in progressing varus gonarthrosis and to explore the interrelation of each component.

PATIENTS AND METHODS

From January to July 2017, radiographic images of 1538 knees of 883 consecutive patients were collected and analyzed. We drew the alignments and measured the orientation angles of the lower extremities and compared the results among age groups for each sex. Correlation and regression tests were used to analyze the measurements.

RESULTS

There were significant differences in the neck-shaft angle (NSA), femoral bowing angle (FBA) and anatomic medial distal femoral angle (aMDFA) by age group in females, whereas the differences were not significant in males. In females, a positive correlation was found between age and the FBA and aMDFA (r = 0.253, 0.141, p<0.01), and a negative correlation was found between age and the NSA while the FBA was controlled (r = -0.065, p<0.05). The FBA was positively correlated with the NSA (r = 0.312, p<0.01) and aMDFA (r = 0.233, p<0.01). The NSA, FBA, and aMDFA together affected 72.2% of the mechanical medial distal femoral angle (mMDFA) (β = 0.071, -0.528, 0.803, p<0.01).

CONCLUSION

As knee osteoarthritis (KOA) progressed, dynamic deformation of the femur was found in females, while no obvious changes were found in males. Femoral mechanical axis varus (mMDFA decrease) was the result of changes in the NSA, FBA and aMDFA. The deformation was throughout the femur rather than in a local area, as femur bowing can lead to corresponding changes in both ends of the femur. We provided a theoretical basis for TKA and knee-salvage treatment, and more attention should be paid to aging patients, especially females, in the preoperative protocol for orthomorphia.

Proximal fibular osteotomy in the treatment of medial osteoarthritis of the knee - A narrative review of literature

Proximal fibular osteotomy has been proposed as a simple and inexpensive alternative to high-tibial osteotomy and unicondylar knee arthroplasty and may be useful for low-income populations that cannot afford expensive treatment methods. However, there is no consensus existing regarding the mechanism by which it acts nor the outcome of this procedure. This study was performed to analyze the available evidence on the benefits of proximal fibular osteotomy and to understand the possible mechanisms in play. There are various mechanisms that are proposed to individually or collectively contribute to the outcomes of this procedure, and include the theory of non-uniform settlement, the too-many cortices theory, slippage phenomenon, the concept of competition of muscles, dynamic fibular distalization theory and ground reaction vector readjustment theory. The mechanisms have been discussed and future directions in research have been proposed. The current literature, which mostly consists of case series, suggests the usefulness of the procedure in decreasing varus deformity as well as improving symptoms in medial osteoarthritis. However, large randomised controlled trials with long-term follow-up are required to establish the benefits of this procedure over other established treatment methods.

Medial compartment defects progress at a more rapid rate than lateral cartilage defects in older adults with minimal to moderate knee osteoarthritis (OA): data from the OA initiative

PURPOSE

To determine: (1) rates and risk factors for progression of lateral and medial full-thickness cartilage defect size in older adults without severe knee osteoarthritis (OA), and (2) whether risk factors for defect progression differ for knees with Kellgren-Lawrence OA grade 3 (moderate) OA versus grades 0-2 (none to mild) OA.

METHODS

Three-hundred and eighty adults enrolled in the Osteoarthritis Initiative were included (43% male, mean age 63.0 SD 9.2 years). Ethical approval was obtained at all study sites prior to enrollment. All participants had full-thickness tibial or weight-bearing femoral condylar cartilage defects on baseline knee MRIs. Baseline OA grade was KL grade 3 in 71.3% and grades 0-2 in 21.7% of participants. Repeat MRIs were obtained at a minimum 2-year follow-up. Independent risk of progression in defect size due to demographic factors, knee alignment, OA grade, knee injury and surgery history, and baseline knee symptoms was determined by multivariate Cox proportional hazards and linear regression modeling.

RESULTS

The average increase in defect size over 2 years for lateral defects was 0.18 cm² (SD 0.60) and for medial defects was 0.49 cm² (SD 1.09). Independent predictors of medical defect size progression were bipolar defects (beta 0.47 SE 0.08; p < 0.001), knee varus (per degree, beta 0.08 SE 0.03; p = 0.02) and increased weight (per kg, beta = 0.01 SE 0.004; p = 0.01). Independent predictors for lateral defect progression were larger baseline defect size (per 1.0 cm², beta 0.14 SE 0.03; p < 0.001) and tibial sided defects (beta 0.12 SE 0.04) and degrees valgus (per degree, beta 0.04 SE 0.01; p = 0.001).

CONCLUSIONS

Medial compartment full-thickness defects progress at a more rapid rate than lateral defects in older adults with minimal to moderate OA. Medial defect progression was greatest for bipolar defects in heavier adults with varus knees. Lateral defect progression was greatest for large tibial-sided defects in adults with valgus knees.

LEVEL OF EVIDENCE

II.

Anatomical Adaptation of Fibula and its Mechanism of Proximal Partial Fibulectomy Associated with Medial Compartment Knee Osteoarthritis

Objectives

To reveal the anatomical adaptation of the fibula and its relations to age and settlement of the medial tibial plateau, and to explore the mechanism of proximal partial fibulectomy in treating medial compartment knee osteoarthritis (OA).

Methods

A retrospective study was performed in the Third Hospital of Hebei Medical University. Weight‐bearing full‐leg anteroposterior (AP) radiographs of 280 adults (560 knees) obtained from 1 January 2018 to 31 October 2018 were enrolled according to our inclusion and exclusion criteria, including 157 men and 123 women, with an average age of 50.3 ± 14.8 years (range, 19–80 years). Radiographic severity of knee OA was assessed using Kellgren and Lawrence (K–L) grading. The settlement of the medial tibial plateau was evaluated using the medial proximal tibial angle (MPTA). Curvatures of the tibia and the fibula were measured as proximal tibial curvature (PTC), distal tibial curvature (DTC), proximal fibular curvature (PFC), and distal fibular curvature (DFC). Two orthopaedic surgeons performed all the radiological measurements for 30 randomly selected patients, and repeated the measurements 1 week later. Based on the satisfactory intra‐observer and inter‐observer reliabilities (ICC > 0.9), each parameter was analyzed in this study. Multivariable linear regression models were used to examine relations between radiological measurements and age.

Results

The mean MPTA, PTC, DTC, PFC, and DFC were 85.4° ± 2.8°, 176.2° ± 1.9°, 176.8° ± 1.8°, 176.8° ± 1.9°, and 177.0° ± 2.0°, respectively. Ninety‐three knees of K–L grade I were categorized as non‐knee OA, and 467 knees of K–L grades II–IV were categorized as knee OA. The MPTA, PTC, and PFC of the knee OA group were significantly smaller than those of non‐knee OA group (P < 0.05). The K–L grade of knee OA significantly increased with age (χ² = 182.169, P < 0.01). The multivariate linear regression analysis indicated that the MPTA and fibular curvatures were negatively correlated with age (the regression equation is age = 561.165–0.945 MPTA‐0.937 PFC‐0.959 DFC, P < 0.05), and the MPTA was negatively correlated with PFC (the regression equation is MPTA = 7.827 + 0.099 DFC, P < 0.05).

Conclusions

The proximal curve of the fibula increased in patients with medial compartment knee OA, and this change was positively correlated with age and settlement of the medial tibial plateau. This anatomical adaptation of the fibula was associated with greater fibular axial load and the pulling from the peroneus longus. The proximal partial fibulectomy procedure effected a receptive foot pronation to reduce KAM and rebalance the biceps‐proximal fibula–peroneus longus complex, consequently achieving medial compartment unloading.

Role of full-thickness cartilage defects in knee osteoarthritis (OA) incidence and progression: Data from the OA Initiative

The purpose of this study is to determine whether full-thickness tibiofemoral cartilage defects are predictive of incident radiographic OA, progression of radiographic OA, and progression to severe radiographic OA. Participants in the OA Initiative (n = 1317, 38.1% male, mean age 60.9 years SD 9.2) with baseline MRIs and Kellgren-Lawrence (KL) OA grade 0-3 (none to moderate OA) were included. All participants had follow-up radiographs at mean 4.9 years (max 8.0). The effect of full-thickness defect presence, size, and location on risk of incident OA (KL grade 2+), overall progression of OA (increase in KL grade 1+ points), or compartment-specific OA progression was assessed with Cox proportional hazards modeling with adjustment for demographic factors, weight, and knee alignment. The yearly incidence of tibiofemoral OA was 0.3% (CI 0.2-0.4%); defect presence, size, and location were not associated with incident OA risk. The yearly rate of OA progression was 3.8% in participants without tibiofemoral full-thickness defects, 6.7% with medial defects, and 6.3% with lateral defects. Medial bipolar (kissing) lesions were an independent risk factor for OA progression as well as medial compartment progression. Lateral tibial-sided full-thickness defects increased risk of lateral progression (increase in lateral OARSI grade). In older adults, isolated full-thickness cartilage defects do not increase short-term risk of incident OA. However, in the setting of preexisting mild or moderate OA, medial bipolar (kissing) defects increase risk of overall OA progression (KL grade) as well as progression of medial compartment OA. Lateral tibial defects increase risk of lateral compartment OA progression. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Microstructure of osteophytes in medial knee osteoarthritis

Knee osteoarthritis (OA) is one of the most common musculoskeletal diseases and osteophytes area frequent radiographic feature of knee OA. The osteophyte structure in knee OA, however, is not well elucidated. This study aimed to clarify the three-dimensional microstructural characteristics of osteophytes in the medial compartment of the knee in knee OA patients using micro-computed tomography (micro-CT). We hypothesized that the morphology of osteophytes would differ from that of the neighboring normal cancellous bones. Ten medial compartment knee OA patients with Kellgren-Lawrence grade 4 severity were enrolled in the study, and all patients underwent total knee arthroplasty. Osteophytes and cancellous bones were obtained from the medial femoral condyle. The three-dimensional trabecular bone microstructure was analyzed by quantitative micro-CT using image analysis software. The trabecular bone volume fraction and trabecular number were significantly lower in osteophytes than in cancellous bones. Consistently, trabecular separation was significantly higher in osteophytes. Osteophytes exhibited disorganized trabecular orientation, trabecular perforation, disruption, and complete disconnection. These findings suggest that osteophytes are functionally fragile.

Proximal fibular osteotomy to treat medial compartment knee osteoarthritis: Preoperational factors for short-term prognosis

Objective

The purpose of this study was to determine the association between preoperational factors and patients’ short-term outcome after proximal fibular osteotomy (PFO) and to provide a basis for detailed surgical indication and patient selection.

Methods

This was a retrospective study of patients undergoing PFO between January 2015 and December 2015. Preoperational clinical data including gender, age, duration of disease, visual analogue score (VAS) and American Knee Society (KSS) score were collected. The radiological factors including hip-knee-ankle angle (HKA angle), condyle-plateau angle (CP angle), Kellgren and Lawrence grade (KL grade), joint space width of both compartments and settlement value were also considered. Patients were followed for at 12 months postoperatively. Both clinical and functional KSS scores were obtained. The outcome of interest was divided into clinical outcome and functional outcome. For each, two criteria were defined: satisfaction and significant improvement. Satisfaction is characterized by a KSS clinical or functional score over 70 points (excellent and good results); significant improvement refers to an increase in KSS scores of more than 15 points. Bivariate logistic regression for the association between preoperational factors and outcomes of interest was performed. Multivariable logistic regression analyses were used to detect the independent factors affecting the outcomes.

Results

A total of 84 patients and 111 knees were followed-up. Of these, 17 knees were from males and 94 were from females. The average age was 59.45±8.82 years. The average preoperational VAS score, KSS clinical and functional score were 7.08±1.41 points, 49.14±10.95 points and 44.97±17.71 points, respectively. According to KL grading, there were 17 knees of grade 2, 47 knees of grade 3, and 47 knees of grade 4. In clinical outcomes, there were 51 knees in the satisfaction group and 77 knees in the significant improvement group. In functional outcomes, 43 knees were in the satisfaction group and 76 knees in the significant improvement group. KSS clinical score (OR = 1.134, 95%CI = 1.067–1.205, P = 0.000) was the independent factor associated with clinical satisfaction. Age (OR = 1.072, 95%CI = 1.000–1.150, P = 0.048), VAS score (OR = 1.679, 95%CI = 1.041–2.706, P = 0.033), KSS clinical (OR = 1.072, 95%CI = 1.005–1.144, P = 0.034) and functional (OR = 1.100, 95%CI = 1.044–1.159, P = 0.000) score, HKA angle (OR = 1.345, 95%CI = 1.119–1.617, P = 0.002) and settlement value (OR = 7.540, 95%CI = 1.307–43.484, P = 0.024) were the independent factors associated with functional satisfaction. KSS clinical (OR = 0.905, 95%CI = 0.850–0.963, P = 0.002) score, CP angle (OR = 0.760, 95%CI = 0.593–0.973, P = 0.030) and medial joint space width (OR = 0.001, 95%CI = 0.000–0.107, P = 0.003) were the independent factors associated with significant clinical improvement; VAS score (OR = 1.582, 95%CI = 1.042–2.402, P = 0.031), KSS functional (OR = 0.888, 95%CI = 0.838–0.942, P = 0.000) score, HKA angle (OR = 1.292, 95%CI = 1.101–1.518, P = 0.002) and settlement value (OR = 9.990, 95%CI = 1.485–67.197, P = 0.018) were the independent factors associated with significant functional improvement.

Conclusions

The independent factors affecting postoperative clinical outcome after PFO were KSS clinical score, CP angle and medial joint space width. In addition, the independent factors that influenced functional outcome included age, VAS score, KSS score, HKA angle and settlement value. As objective radiological evidence, HKA angle and settlement value could be used as an important basis for patient selection for PFO.

Multivariate analysis of factors related to radiographic knee osteoarthritis based on the comparison between football players and matched nonsportsmen

PURPOSE

Knee osteoarthritis (KOA) is the most common joint pathology worldwide and a major cause of later disability. It is unknown if the bone mass density (BMD) is correlated with KOA. This study aimed to investigate the prevalence of radiographic KOA among retired professional football players by comparing with matched nonsportsmen, and assess the correlation between BMD and KOA.

METHODS

A cross-sectional, descriptive study was performed on a group of retired professional football players without history of knee injury. A control group of nonsporting volunteers was matched to the football player group in terms of age, height, weight, and body mass index (BMI). Uni- and multivariate analyses were performed to identify risk factors for KOA and predictors for knee function.

RESULTS

Eighty-six retired male professional football players, with a mean age of 53 (51-58) years and an average period of professional career of 19.8 ± 6.3 years, were enrolled into the study group. Eighty-six subjects were included in the control group. Radiographic KOA was more common in the control group (45.3%) than in the study group (15.1%; χ ²  = 18.633, P < 0.001). While the HSS, IKS score, and BMD of spine, femoral neck, and trochanter were all higher among sportsmen than the nonsportsmen (z = 10.250, z = 10.450, z = 7.237, z = 8.826, z = 8.776, all P < 0.001). Independent risk factors for ROA were age (55-60 + years, aOR 9.159, P < 0.001) and BMD (decrease, aOR 16.226, P = 0.001; osteoporosis, aOR 8.176, P = 0.005). The mathematical model of multiple linear regression for the HSS and IKS score were Y = 127.217-3.334 age + 8.971 BMD + 4.752 occupation and Y = 57.784-3.022 age + 7.241 BMD + 4.730 occupation, respectively.

CONCLUSIONS

This study reveals that low BMD and advanced age are independent risk factors for KOA. High BMD and regular exercise have a positive impact on knee function as evaluated with the use of HSS and IKS. Our findings guarantee further study to investigate the possibility that KOA may be caused by low BMD.

Comparison of tissue transglutaminase 2 and bone biological markers osteocalcin, osteopontin and sclerostin expression in human osteoporosis and osteoarthritis

Osteoporosis (OP) and osteoarthritis (OA) are the most common joint diseases, with a high incidence in the elderly population. OP is characterized by trabecular bone remodeling and reabsorption, whereas articular cartilage and subchondral bone remodeling are major features of OA. Although classically considered as independent or even conflicting processes, clinical coexistence of OP and OA was recently described. Transglutaminase 2 (TG2) expression is considered a biomarker of OA, but its role in osteoporotic bone remodeling is still uncertain. We investigated TG2 and bone biological markers (Osteocalcin, Osteopontin, and Sclerostin) in osteoporotic and osteoarthritic osteocartilagineous tissue (n = 54) and human chondrocyte cultures in vitro by immunohistochemistry, immunofluorescence and RT-PCR. Histomorphometric evaluation of bone trabecular remodeling was also performed. In cartilage, TG2 expression was faint in control and OP and significantly less than in OA and OP + OA chondrocytes; the opposite was found for Osteocalcin, whereas Osteopontin and Sclerostin expression was similar. In the subchondral trabecular bone, osteocytes/osteoblasts TG2 expression was slight and similar comparing control, OP, OA, and OP + OA group, whereas Osteocalcin and Osteopontin expression was lower in OP compared to control, OA and OP + OA. Increased TG2 and reduced Osteocalcin expression were maintained in human osteoarthritic chondrocytes in vitro. Histomorphometric analysis confirmed reduced trabecular bone mass in OP and OP + OA compared with OA patients. TG2 represented a suitable biomarker of osteoarthritic chondrocyte activation, whereas osteocalcin and osteopontin characterized osteoporotic osteocyte/osteoblast changes; differences were lost in OP + OA patients, suggesting careful consideration when coexistence of the two diseases occurs.