Current surgical strategies for total arthroplasty in valgus knee

Functional alignment in robotic-assisted total knee arthroplasty for valgus deformity achieves safe coronal alignment and excellent short-term outcomes

PURPOSE

Functional alignment (FA) in total knee arthroplasty (TKA) prioritizes soft tissue balancing and anatomical restoration without systematic correction to neutral alignment. Most studies have focused on varus deformity, with little evidence available about FA in valgus deformity. The hypothesis of the present study was that FA in robotic-assisted TKA for valgus deformity would demonstrate correction of the coronal alignment and yield satisfactory short-term outcomes.

METHODS

This retrospective study included 58 patients with valgus coronal alignment (hip-knee-angle [HKA] ≥ 183°) who underwent robotic-assisted TKA using the FA technique with a minimum of 1-year follow-up. Outcomes were assessed through the Knee Society Score (KSS), Oxford Knee Score (OKS), Forgotten Joint Score (FJS) and radiographic measurements of alignment and phenotypes. Complication and revision rates were also analyzed.

RESULTS

The cohort included 39 females and 19 males with a median age of 70. Post-operatively, 86.2% of cases achieved coronal alignment within the safe zone (HKA 177-183°). Significant improvements were observed in KSS (part 1: 69.5-95, part 2: 65-94, p < 0.001), while OKS and FJS exhibited optimal outcomes. Two complications were recorded: one aseptic loosening (1.7%) and one early infection (1.7%). Kaplan-Meier survival analysis indicated favourable implant survivorship at a median follow-up of 18 months.

CONCLUSION

FA in image-based robotic TKA is a safe and effective approach for patients with valgus deformity. This procedure resulted in a modest correction of the coronal alignment, where no soft tissue releases were needed. The majority of the cases fell within the target coronal alignment boundaries by only accommodating the individual laxities, suggesting the aim of FA to restore each knee's pre-pathological alignment.

LEVEL OF EVIDENCE

Level IV.

Complex primary total knee arthroplasty with constrained condylar knee in post-traumatic arthritis: a retrospective comparison between 3D-printed patient-specific instrumentation and conventional instrumentation

BACKGROUND

Complex primary total knee arthroplasty (TKA) using constrained implants for post-traumatic arthritis (PTA) presents significant surgical challenges and is associated with higher complication rates compared to routine TKA procedures. This study aimed to analyze the demographic characteristics and operative details of patients undergoing complex primary TKA with constrained condylar knee (CCK) implants following intra- or extra-articular peri-knee fractures and to compare short- to medium-term clinical outcomes between three-dimensional (3D)-printed patient-specific instrumentation (PSI) and conventional instrumentation in these procedures.

METHODS

We conducted a retrospective analysis of patients who underwent complex primary CCK-TKA for post-traumatic arthritis using either 3D-printed PSI or conventional instrumentation at our institution between January 2015 and December 2020. Demographic data, perioperative parameters, radiographic outcomes, and clinical efficacy measures were compared between the two groups. Complications were recorded, and implant survival rates were calculated.

RESULTS

The study included 55 patients with a mean follow-up of 82 months (range 49-109). A notable prevalence of severe preoperative valgus deformity was observed (26/55, 47.27%), and regression analysis identified a history of lateral compartment fracture as an independent risk factor for the development of valgus deformity (OR 6.28, 95% CI 1.40-28.30, P = 0.017). Compared to the conventional group (n = 26), the PSI group (n = 29) demonstrated significantly shorter operative time, reduced blood loss, improved postoperative mechanical alignment, and superior final follow-up scores for range of motion (ROM) and Hospital for Special Surgery (HSS) knee scores. Wound complications occurred in 1 case in the PSI group versus 7 cases in the conventional group. One patient in the conventional group required reoperation due to infection and patellar osteonecrosis. Both groups maintained 100% implant survival (revision-free) at final follow-up.

CONCLUSION

Severe valgus deformity appears to be a key indication for constrained implants in this population, and a history of lateral tibial plateau fracture may contribute to the development of valgus deformity prior to TKA. CCK-TKA proves to be a safe and effective method for managing complex PTA. Our findings suggest that 3D-printed PSI may enhance surgical precision, reduce operative trauma, and improve radiographic and clinical outcomes in the short to medium term compared to conventional techniques.

Patient-Specific total knee arthroplasty for valgus osteoarthritis results in the use of minimal thickness polyethylene liners in low constraint implants

BACKGROUND

Correction of valgus knee deformity during total knee arthroplasty (TKA) can present numerous challenges. This study assessed the ability of a patient-specific knee design to allow easier intraoperative balancing of valgus knees in primary TKA.

MATERIALS AND METHODS

This study utilized a database consisting of de-identified computed tomography (CT) scans, low constraint knee designs (CR or PS), tibial and femoral implant dimensions, and implanted polyethylene (PE) thickness for all patients who underwent primary TKA with a patient-specific knee design provided by Conformis Inc. (Boston, MA, US). Data were analyzed for knee design, coronal deformity, native posterior and distal femoral offset, and PE thickness.

RESULTS

A total of 26,227 cases were included, of which 25% had valgus deformity. In the PS group, the thinnest available PE (6 mm) was used for 64% of varus cases and 68% of valgus cases (P = 0.004). There was no difference in the distribution of thin (≤ 8 mm) and thick (> 8 mm) PE between varus or valgus knees with 0-5 degrees or > 10 degrees of deformity. Knees with varus deformity of 5-10 degrees were more likely to receive a thick PE than knees with valgus deformity of 5-10 degrees. For the CR group, the thinnest available PE (6 mm) was used in 77% of varus cases and 76% of valgus cases (P = 0.12). There was no difference in the distribution of thin and thick PE between varus or valgus knees regardless of deformity. Over 99% of CR knees received PE with thicknesses 8 mm or less, regardless of degree of preoperative varus or valgus deformity.

CONCLUSIONS

These results indicate that patient-specific instrumentation in TKA can facilitate valgus deformity correction without requiring increased PE thickness to achieve balancing. Patient-specific knee designs may reduce the difficulty of valgus knee correction while allowing the use of minimal thickness PEs in low constraint TKA implants.

Lateral approach in robotic total knee arthroplasty for valgus knees: A step-by-step technique

Total knee arthroplasty (TKA) in valgus knee deformities presents unique challenges, including alignment, soft tissue balance, and implant positioning. The lateral approach offers advantages over the traditional medial approach by improving direct access, patellar tracking, and soft tissue preservation. Robotic-assisted TKA enhances precision, ligament balancing, and patient-specific alignment strategies, such as functional knee positioning (FKP). This study describes a surgical technique integrating the lateral approach with robotic-assisted TKA using FKP principles. The technique is based on an image-based robotic system, ensuring accurate preoperative planning, intraoperative adjustments, and optimized prosthetic placement. Key intraoperative steps, including bone resection strategies, soft tissue balancing, and trial component evaluations, are detailed. The lateral robotic approach with FKP was found to be effective and reproducible, allowing for precise implant alignment and optimized soft tissue balance in valgus knees. This method minimizes the need for extensive lateral releases, preserves vascularity, and ensures postoperative stability. The combination of the lateral approach, robotic-assisted TKA, and FKP represents a promising strategy for valgus knee deformities. Further long-term studies are needed to validate the durability and functional benefits of this technique.

Functional knee positioning in patients with valgus deformity undergoing image-based robotic total knee arthroplasty: Surgical technique

BACKGROUND

Functional knee positioning (FKP) represents an innovative personalized approach for total knee arthroplasty (TKA) that reconstructs a three-dimensional alignment based on the optimal balance of soft tissue and bony structures, but it has mostly been described for varus knee deformity.

SURGICAL TECHNIQUE

Valgus deformities present specific challenges due to altered bone remodeling and soft tissue imbalances. Using robotic assistance, FKP enables precise intraoperative assessment and correction of compartmental gaps, accommodating each individual's unique anatomy and laxities. The distal femoral cut is calibrated for 9 mm resection at the intact medial femoral condyle and adjusted on the lateral side to accommodate bone wear, while the tibial plateau resection aims for 8 mm from the medial side and 4-6 mm from the lateral side. Intraoperative evaluations of mediolateral laxities are performed at extension and 90° flexion. Adjustments are made to femoral and tibial cuts to balance gaps, aiming for 0 mm in posterior stabilized implants and minimal discrepancies in cruciate-retaining designs with lateral gap looser in flexion.

DISCUSSION

FKP emphasizes soft tissue-driven adjustments with the use of robotic platforms. Hence, intact soft tissue envelope of the knee is essential. This technique holds significant promise for managing valgus deformities in TKA, but further research is needed to evaluate its functional outcomes.

Medial open wedge osteotomy yields comparable stability to lateral open wedge procedure on the distal femur

BACKGROUND

Supracondylar osteotomies are a frequently and successfully used technique in the treatment of coronal plane deformities and unicompartmental osteoarthritis of the knee. While lateral open wedge techniques are common for valgus deformities, the data about medial open wedge techniques for varus deformities is sparse. The aim of this study was to compare the biomechanical properties of medial and lateral open wedge osteotomies using a locking Tomofix® plate (DePuy Synthes, Oberdorf, Switzerland). Our hypothesis was that there would be no difference regarding biomechanical outcome parameters between these two groups.

METHODS

Medial and lateral open wedge osteotomies were performed in composite bone model as routine. Each experimental group contained 6 constructs. Standardized osteotomy gaps of ten millimeters were performed and Tomofix® plates were fixed to third generation composite bones. The constructs were subsequently mounted into a servohydraulic testing machine. Axial and torsional loadings were applied as described in previous experimental studies. All specimens were subject to a load to failure mode with the mechanism of failure being noted.

FINDINGS

Both experimental groups showed comparable biomechanical properties under axial and torsional loadings. Mean high force axial stiffness was 3772 N/mm for lateral and 4185 N/mm for the medial construct. Significant differences were noted for torsional stiffness under low- (0 N) and mid-force (150 N) loadings (P = 0.002; P = 0.009), favoring the medial open wedge constructs.

INTERPRETATION

Medial open wedge osteotomy yields comparable biomechanical stability to the lateral open wedge procedure on the distal femur in a composite bone model.

Successful Knee Replacement in a Patient With a History of Multiple Knee Surgeries: A Case Report

This case report describes the successful total knee arthroplasty (TKA) in a 58-year-old female with a prior history of multiple knee surgeries. The patient had three prior surgical procedures. The first surgery of the patient was a partial knee replacement, the second surgery the patient underwent was an arthroscopic meniscectomy, and the third surgery was a high tibial osteotomy (HTO) that left her with an extensive amount of scar tissue and a change in physical structure. When scar tissue develops over or close to a joint, the surrounding tissues are pulled inward by this shrinking or contraction. A joint may experience restricted movement as a result of this tightness. Stretchy and excessively flexible joints are common in people with Ehlers-Danlos syndrome. This may become an issue if you need sutures for a wound because the skin is frequently not strong enough to support them. The patient already undergone three surgeries prior but still showed signs of severe pain, swelling, and stiffness in the knee which made the patient suffer more during rest position and also made it sometimes so difficult that it affected everyday tasks. In this situation when the patient consulted the doctors, the patient was suggested to undergo TKA. TKA is the method of orthopedic surgical technique that is most consistently successful and highly effective. Patients with end-stage degenerative knee osteoarthritis might expect reliable results from this surgery. The case demonstrates the preoperative planning, surgical methods, and postoperative care needed to successfully treat a complicated patient profile. Hospital protocols were followed, and the patient's surgery was done with proper care and hygiene.

Total Knee Arthroplasty With Lateral Parapatellar Approach Results in Less Early Postoperative Skin Numbness Than Medial Approach, but No Difference at Mid-Term Follow-Up: A Randomized Control Trial

Background

Anterior skin numbness is a common complication after total knee arthroplasty (TKA) that may impact postoperative functional outcomes. This study aimed to compare skin numbness area, functional outcomes, and patient satisfaction between patients undergoing TKA with a medial parapatellar approach (medial group) and a lateral parapatellar approach (lateral group).

Methods

A prospective randomized study included 68 knees undergoing TKA via the medial parapatellar approach (n = 32) and the lateral parapatellar approach (n = 32) through the midline skin incision. Anterior skin numbness was assessed as the primary outcome using Semmes-Weinstein monofilaments at 6 postoperative timepoints (2 weeks, 6 weeks, 3 months, 6 months, 1 year, and 2 years). Knee range of motion, Knee Injury and Osteoarthritis Outcome Score (KOOS), and patient satisfaction scores were collected. Fifty-nine patients were retrieved at the 2-year final follow-up. Statistical analysis considered repeated outcome measurements with adjusted P-values.

Results

The lateral group had a significantly smaller area of anterior skin numbness at 2 weeks (11.2 vs 20.2 sq.cm.), 6 weeks (8.2 vs 17.2 sq.cm.), and 3 months (7.8 vs 14.4 sq.cm.) postoperatively compared to the medial group. No difference in the area of numbness was found at 6 months, 1 year, and 2 years. Although the lateral group showed significantly higher satisfaction scores (P = .027) and the KOOS symptoms subdomain (P = .018), there were no differences in knee range of motion and other components of KOOS in both groups.

Conclusions

Compared to the medial approach, the lateral parapatellar approach in TKA demonstrates a reduced area of early postoperative skin numbness and expedited 6-month recovery, along with marginally superior patient satisfaction scores. However, both approaches yield comparable outcomes in terms of postoperative knee motion and overall functional outcomes.

Why Kinematic Alignment Makes Little Sense in Valgus Osteoarthritis of the Knee: A Narrative Review

There is a debate about the best alignment strategies in total knee arthroplasty (TKA). Mechanical alignment (MA) targets in combination with necessary soft tissue releases are the gold standard for TKA in end-stage valgus osteoarthritis. Some authors propagate kinematic alignment (KA) with the aim of restoring the patient's native alignment and minimizing the need for soft tissue releases. Our previous studies showed that MA with standardized soft tissue release produces reproducible results, and that the preoperative phenotype does not influence the results of patients with valgus osteoarthritis. These data suggest that there is no functional advantage to preserving valgus alignment in patients with valgus osteoarthritis. Many patients with valgus osteoarthritis present with a compromised medial collateral ligament and leaving the knee in valgus could increase the risk of secondary instability. The current literature supports MA TKA with soft tissue release as the gold standard. While using more sophisticated enabling technologies like robotic surgery might allow for aiming for very slight (1-2°) valgus alignment on the femoral side, any valgus alignment outside this range should be avoided. This review paper summarizes our current knowledge on the surgical techniques of TKA in patients with valgus osteoarthritis.

Total Knee Replacement in a Young Patient with Valgus Knee Osteoarthritis: A Case Report

Introduction

Valgus deformity is characterized by an outward angulation of the knee joint. The most common cause of valgus deformity is osteoarthritis (OA), a prevalent progressive joint disease that causes chronic pain and functional limitations. Total knee replacement (TKR) is rarely done in patients with grade-I valgus deformity and young age. To the best of our knowledge, this is the first case report of its kind.

Case Report

A 34-year-old man presented to us with 15 years of persistent, progressively worsening right knee pain that was interfering with his daily activities. No non-operative treatment could alleviate his severe pain. Physical examination revealed a positive valgus stress test, limited knee extension, and an asymmetrical gait. He was diagnosed with a grade-I valgus deformity of the right osteoarthritic knee. History, physical examination, and radiological findings confirmed the diagnosis. In consideration of severe pain and impaired quality of life, we opted to perform TKR using a medial parapatellar approach. Regular follow-ups were done after the procedure. He experienced no pain or recurrence of deformity. He was very satisfied with the result. His Western Ontario and McMaster Universities OA Index score at 12 months following surgery was 5, indicating a favorable outcome.

Conclusion

This case exhibits the effectiveness of TKR in treating grade-I valgus deformity of the osteoarthritic knee with severe pain in a young adult, resulting in improved pain alleviation, mobility, joint alignment, and overall quality of life.

Total Knee Arthroplasty in the Valgus Knee

An estimated 10 to 15% of total knee arthroplasties (TKAs) are implanted for a diagnosis of arthritis when a valgus deformity is present. There are various techniques and considerations that must be considered for a successful TKA in a patient with a valgus deformity. This article provides a detailed summary of the anatomy, pathology, bone preparation, soft tissue management, implant selection, and complications when performing a TKA in a patient with valgus deformity.

Optimal Sequence of Corrective Surgeries for Concomitant Valgus Knee and Rigid Pes Planus Deformities: The Knee-First Approach

In patients requiring surgical correction of ipsilateral valgus knee and rigid pes planovalgus deformities, the optimal operative sequence is controversial. Growing evidence suggests these 2 deformities are related in etiology and interrelated in disease course. We present the case of a 72-year-old female with concomitant valgus knee and rigid pes planovalgus deformities successfully treated with total knee arthroplasty followed by triple arthrodesis and Achilles lengthening. Surgical correction of these deformities must be carefully planned between the operating surgeons to avoid over- or under-correction of alignment that could further impact gait. In contrast with the limited available literature, the authors recommend correction at the knee first and the foot and ankle second. Further prospective studies are needed to elucidate the best operative sequence in these patients.

Effect of total knee arthroplasty for valgus knee correction on clinical outcome and patellar position

PURPOSE

The purpose was to investigate the effect of different degrees of valgus deformity correction on patellar position and clinical outcome in patients with valgus knees after total knee arthroplasty (TKA).

METHODS

We retrospectively analyzed and followed 118 patients with valgus knees. Based on the post-operative hip-knee-ankle (HKA), patients were divided into three groups: neutral (±3°), mild (3-6°), and severe (> 6°). Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), range of motion (ROM), and Knee Society Score (KSS) were used to evaluate post-operative clinical efficacy. Also, the patellar tilt angle (ε-angle), congruence angle (θ-angle), and Insall-Salvati index (ISI) were used to represent the patellar position. Post-operative observation indicators included HKA, angle of the femur (α-angle), tibial angle (β-angle), femoral component flexion angle (γ-angle), and tibial component posterior slope angle (δ-angle).

RESULTS

All patients showed significant improvements in HKA, ROM, WOMAC, and KSS after operation (P < 0.001). Regarding patellar position, the ISI values decreased to varying degrees (P < 0.05). The patellar tilt angle was significantly increased in the severe valgus group compared to that in the mild valgus and neutral groups (P < 0.001). Univariate analysis showed that the degree of post-operative residual valgus was significantly affected by WOMAC, KSS, α-, ε-, and θ-angles.

CONCLUSION

Minor valgus undercorrection did not affect the short-term outcome after TKA; however, when the residual valgus angle was > 6°, the post-operative scores were significantly reduced. Inadequate valgus correction does not result in significant changes in patellar height but may increase the risk of poor patellar tracking.

Fixed distal femoral resection with a valgus cutting angle of 3° is more appropriate in intra-articular valgus deformity than juxta-articular valgus deformity in total knee arthroplasty: a retrospective single center study

Background

The traditionally recommended fixed valgus cutting angle (VCA) of 3° is used as the standard method in total knee arthroplasty (TKA) for valgus deformity. The accuracy of distal femur cutting can be affected by the type of valgus deformity because the intramedullary rod for distal femoral resection can become impinged on the femoral cortex. The purpose of this study is to analyze the accuracy and precision of a VCA of 3° in mechanical alignment in TKA for valgus deformity, based on the type of the deformity.

Methods

TKAs with a fixed VCA of 3° performed in 110 intra-articular and 102 juxta-articular valgus knees were retrospectively reviewed. The age (65.8 vs. 66.1 years), sex (female: male =78/32 vs. 70/32), body mass index (26.0 vs. 26.0), and severity of deformities (valgus 12.1 vs. valgus 12.5) were not significantly different (P>0.647). The mechanical-lateral-distal-femoral angle (mLDFA) and anatomical-mechanical-axis angle (AMA-A) were evaluated. The adjusted-VCA (aVCA) was defined as the maximum angle within the range without the intramedullary rod impinging on the femoral cortex. The proportion of well-aligned femoral component (mLDFA <90°±3°) was assessed. The correlation between AMA-A-3° or aVCA-3° and postoperative mLDFA-90° was analyzed.

Results

Despite the larger AMA-A in the juxta-articular group (6.2° vs. 6.8°, P<0.001), the aVCA was lesser in the juxta-articular group (5.4° vs. 4.1°, P<0.001). The mLDFA was more varus in the intra-articular group (91.7° vs. 90.6°, P<0.001) postoperatively. The proportion of well-aligned femoral component was higher in the juxta-articular group (85.3% vs. 70%, P=0.009). Postoperative mLDFA-90° was moderately correlated with aVCA-3° (r=0.301, r=387), but weakly correlated with AMA-A-3° (r=0.274, r=294) in both groups.

Conclusions

Although a fixed VCA of 3° is a reliable method in achieving mechanical alignment in valgus deformity, it can be more appropriate in juxta-articular deformity than in intra-articular deformity. The aVCA is a more reasonable predictor of femoral component alignment than the AMA-A, considering the femoral cortex impingement of the intramedullary rod.

Dynamic gap analysis of valgus knees shows large inter-individual variability of gaps

PURPOSE

The purpose of this study was to investigate the dynamic gap widths of valgus knees in extension and flexion to evaluate the influence of deformity on gap differences and to find out whether different ligamentous subtypes in valgus knees exist.

METHODS

Dynamic gap widths of 1000 consecutive total knee arthroplasty (TKA) patients were measured at different flexion angles by applying a computer-assisted surgery (CAS) technique. 198 knees showed a valgus deformity and were assessed regarding its degree of fulfillment of the following criteria of valgus knee: 1. Medial extension gap greater than lateral; 2. Medial flexion gap greater than lateral; 3. Flexion gap greater than extension gap. A single-factor ANOVA subgroup analysis was performed, based on the amount of deformity. The effect of other patient factors (age, gender, weight) on gap differences was investigated.

RESULTS

The medial extension gap (3.7 ± 2.2 mm) was significantly (p < 0.01) larger than the lateral extension gap (1.1 ± 2.9 mm). The amount of deformity correlated highly with gap difference in extension (r² = 0.67) but not in flexion. In 92.4% (183), the flexion gap (6.2 ± 3.1 mm) was significantly (p < 0.01) larger than the extension gap (2.4 ± 2.3 mm). Only 29.3% (58) of patients met all three criteria, this was mainly due to the fact that in flexion the medial gap was larger than the lateral in only 35.4% (70). Patient factors showed no significant influences (NS) on the gap widths.

CONCLUSION

Valgus knees show large variability in terms of gap widths. The extent of deformity correlates highly with gap difference in extension, but not in other flexion angles. Vast majority of valgus knees were valgus in extension only. Because of this variability, it should be aimed for an individualized balancing technique based on intraoperative gap sizes.

LEVEL OF EVIDENCE

Level III.

The use of mobile bearing TKA in valgus deformities - A clinical study

BACKGROUND

The number of patients presenting valgus deformities undergoing total knee arthroplasty (TKA) represents approximately 10% of the total number of TKAs performed: the presence of valgus deformity requires the implant to have proper alignment, stability and balance to achieve successful clinical outcomes, especially for knees with high coronal deformities, but these have proven to be difficult goals to achieve and therefore the use of constrained prostheses is often recommended for these cases. However, even though the use of unconstrained mobile bearing for severe knee deformities is rare, it has been shown to give successful outcomes and therefore the aim of this study is to evaluate whether this surgical technique can achieve satisfactory clinical results and correct alignment, as well as good patient satisfaction.

METHODS

This study presents the results of 69 TKA performed with cemented mobile bearing implants by a single surgeon on knee affected by valgus deformities. Asymmetric inserts were adopted for all the implants and an alignment surgical tool, dedicated for valgus patients, was used during the operation. Angles of valgus, WOMAC surveys and Numeric Rating Scale for pain were recorded to evaluate the results of the operations.

RESULTS

A total of 67 pre-op WOMAC questionnaire surveys were collected, with the mean result of this evaluation being 15.9 points. The Numeric Rating Scale for pain had an average of 2.2 for 68 tests. The deformities were corrected from a mean total preoperative valgus angle of 12.5° to a postoperative valgus deformity average of 0.6°. During follow-up, only one patient had serious complications due to the rupture of the extensor apparatus following a domestic accident involving falling. Further 10 patients have mild complications related to injuries such as pain of varying intensity, burning, or swelling of the knee. The level of satisfaction from 0 to 10 (0 not at all satisfied and 10 perfectly satisfied) had an average score of 7.7.

CONCLUSIONS

The surgical approach presented, involving a less constrained model if compared to the ones usually chosen, allowed to achieve correct alignment and high patient satisfaction using mobile bearing implants on valgus knee deformities; further patient follow-up will be performed to evaluate long-term outcomes, but the results achieved already represent a significative finding.

Medial closure supracondylar femoral osteotomy: an effective solution for long-term treatment of arthritic valgus knee?

Purpose

The aim of this work was to retrospectively analyze the clinical, subjective, and radiological results of medial closing-wedge distal femur osteotomy (MCW-DFO) for the treatment of osteoarthritis (OA) in valgus knee at medium- to long-term follow-up.

Materials and methods

A total of 57 patients (62 knees) treated with MCW-DFO between 1984 and 2018 were included in the study. Patient age at the time of the surgery ranged between 28 and 61 years (average: 48 years). All patients with a minimum follow-up of 4 years were contacted to request for them to undergo clinical, subjective, and radiological evaluation. Preoperative hip–knee–ankle (HKA) angle (i.e., preoperative valgus malalignment) was 8.6° ± 2°. Patients were evaluated using the following scales: the Knee Injury and Osteoarthritis Outcome Score (KOOS), the Knee Society Score (KSS), the International Knee Documentation Committee (IKDC), the Visual Analog Scale (VAS), and the Numeric Rating Scale 11 (NRS-11).

Results

Mean follow-up was 11.6 ± 4.9 years, and a total of 17 patients (20 knees) were available for the last examination. At maximum follow-up, 4 patients underwent conversion to a total knee replacement (20%); their survival rate was 100% at 10 years and 66.7% at 15 years, as estimated using the Kaplan–Meier curve. The subjective Knee Society Score improved on average from 37.7 ± 10 to 63.9 ± 15.4. The objective Knee Society Score improved on average from 42.2 ± 11.7 to 75 ± 22.5. The pain detected through the VAS and NRS-11 scales improved from 56.7 ± 12.9 to 42 ± 17.1 and from 5.8 ± 1.1 to 4.4 ± 1.7, respectively. Thirteen patients (70%) required hardware removal at an average time of 19 ± 4 months due to a local nuisance.

Conclusions

MCW-DFO can improve symptoms in patients with osteoarthritis in a valgus knee at medium- to long-term follow-up, reducing the progression of osteoarthritis in properly selected patients.

Total knee arthroplasty in valgus knee deformity: is it still a challenge in 2021?

Total knee arthroplasty in valgus knee deformities continues to be a challenge for a surgeon. Approximately 10% of patients who undergo total knee arthroplasty have a valgus deformity. While performing total knee arthroplasty in a severe valgus knee, one should aware with the technical aspects of surgical exposure, bone cuts of the distal femur and proximal tibia, medial and lateral ligament balancing, flexion and extension gap balancing, creating an appropriate tibiofemoral joint line, balancing the patellofemoral joint, preserving peroneal nerve function, and selection of the implant regarding constraint. Restoration of neutral mechanical axis and correct ligament balance are important factors for stability and longevity of the prosthesis and for good functional outcome. Thus, our review aims to provide step by step comprehensive knowledge about different surgical techniques for the correction of severe valgus deformity in total knee arthroplasty.

Strain Assessment of Deep Fascia of the Thigh During Leg Movement: An in situ Study

Fascia is a fibrous connective tissue present all over the body. At the lower limb level, the deep fascia that is overlying muscles of the outer thigh and sheathing them (fascia lata) is involved in various pathologies. However, the understanding and quantification of the mechanisms involved in these sheathing effects are still unclear. The aim of this study is to observe and quantify the strain field of the fascia lata, including the iliotibial tract (ITT), during a passive movement of the knee. Three fresh postmortem human subjects were studied. To measure hip and knee angles during knee flexion-extension, passive movements from 0° to around 120° were recorded with a motion analysis system and strain fields of the fascia were acquired using digital image correlation. Strains were computed for three areas of the fascia lata: anterior fascia, lateral fascia, and ITT. Mean principal strains showed different strain mechanisms depending on location on the fascia and knee angle. For the ITT, two strain mechanisms were observed depending on knee movement: compression is observed when the knee is extended relative to the reference position of 47°, however, tension and pure shear can be observed when the knee is flexed. For the anterior and lateral fascia, in most cases, minor strain is higher than major strain in absolute value, suggesting high tissue compression probably due to microstructural fiber rearrangements. This in situ study is the first attempt to quantify the superficial strain field of fascia lata during passive leg movement. The study presents some limitations but provides a step in understanding strain mechanism of the fascia lata during passive knee movement.

Common peroneal nerve 'pre-release' in total knee arthroplasty for severe valgus deformities

BACKGROUND

Common peroneal nerve (CPN) palsy is a devastating complication that follows total knee arthroplasty (TKA). However, there are only a few studies on concrete measures for protecting the CPN in patients. This study aimed to put forward the CPN 'pre-release' method to protect the nerve.

METHODS

A prospective study was conducted on 30 patients (34 knees) with severe valgus knees who underwent CPN pre-release. This was a two-incision approach, and required a separate dissection of about three centimeters from the TKA operation. Clinical measurements including pre- and postoperative motor and sensory nerve function of CPN, radiological evaluation, complications, and the revised data were analyzed and compared.

RESULTS

The average preoperative femorotibial angle was 31.3 ± 8.0°. All patients had completely normal motor (grade 5) and sensory nerve function of CPN postoperatively, and there was no transient or late-onset CPN palsy. Patients had a routine rehabilitation with full weight bearing after recovery from anesthesia, including the knees with unconstrained extension/flexion motion. During the last follow-up visit, the visual analog scale, Knee Society Score, Hospital for Special Surgery knee-rating scale, and range of motion were 2.06 ± 1.13, 92.18 ± 5.57, 90.18 ± 3.70, and 115.59 ± 7.76°, respectively. There were no revisions for instability and recurrent valgus deformities during follow-up. Also, the femorotibial angle, hip-knee-ankle angle, condylar-hip angle, and plateau-ankle angle were 4.9 ± 2.0°, 179.09 ± 3.21°, 89.97 ± 2.41°, and 90.53 ± 1.26°, respectively.

CONCLUSIONS

The CPN pre-release for severe valgus knees is an effective method for nerve protection, achieving an adequate and safe release of lateral soft tissue, and providing immediate and early functional rehabilitation with decreasing constrained implant.

Tightening medial collateral ligament during total knee arthroplasty for patients with fixed valgus deformity: A novel technique

BACKGROUND

This study aimed to explore a new surgical technique for gap balance by tightening the medial collateral ligament (MCL) in total knee arthroplasty (TKA) in patients with fixed valgus deformity.

MATERIALS AND METHODS

A prospective analysis was performed on 15 patients (16 knees) with a fixed valgus deformity that was corrected by tightening the MCL during TKA. A single surgeon performed all the 16 TKAs using nonconstrained posterior substituting implant, with two knees treated with long-stem tibial prosthesis. Clinical scores, knee stability, and radiographic evaluations were recorded preoperatively and postoperatively.

RESULTS

Complete weight-bearing could be carried out under the protection of the brace postoperatively. At the third month after surgery, X-rays showed the brace was not worn. The mean follow-up was 26.6 months (range 12-42 months). The average preoperative mechanical axis was 15.4 ± 2.3° (range 11-25°), and postoperatively it was 0.6 ± 0.1° (range 0-2°). No complication relative to the technique occurred.

CONCLUSION

This new surgical technique has demonstrated excellent early clinical results and can be a good supplement for fixed valgus knee arthroplasty. Level of Evidence: III.

Re-revision surgery for re-recurrent valgus deformity after revision total knee arthroplasty in a patient with a severe valgus deformity: A case report

BACKGROUND

A recurrent valgus deformity was a common complication after total knee arthroplasty (TKA) in patients with valgus deformity. However, re-revision surgery for re-recurrent valgus deformity after revision TKA in patients with valgus deformity before primary TKA was uncommon.

CASE SUMMARY

We reported a 72-year-old female patient with two recurrent valgus deformities after TKA for a valgus knee deformity who underwent two revision surgeries to rectify the deformity. In the re-revision surgery, bone defects were successfully reconstructed by the augments and cement in combination with screws and a sleeve. An appropriate neutral alignment of the lower limb was restored by the perfect femoral entry point and the long diaphyseal cementless stem. Adequate fixation of the metaphysis and diaphysis of the femur was obtained by the sleeve and long diaphyseal cementless stem. The patient was pain-free and deformity-free for 2.5 years.

CONCLUSION

The management of bone defects, the choice of the stem and the femoral entry point were of vital importance in the revision or re-revision TKA for a recurrent valgus deformity.

Application of 3D printed osteotomy guide plate-assisted total knee arthroplasty in treatment of valgus knee deformity

INTRODUCTION

To analyze the application of 3D printed osteotomy guide plate-assisted total knee arthroplasty (TKA) for valgus knee deformity.

METHODS

The clinical data of 20 patients with valgus knee deformity admitted to our hospital from April 2012 to April 2017 were collected and analyzed. According to the treatment method, these patients were divided into two groups: 3D printed osteotomy guide plate-assisted TKA (combined treatment group, n = 10) and TKA (treatment group, n = 10). The operation time, intraoperative bleeding volume, postoperative mean femorotibial angle (MFTA), and Knee Society Score (KSS) of the two groups were statistically analyzed.

RESULTS

Compared with the treatment group, the operation time was significantly shorter (P < 0.05), the intraoperative blood loss and postoperative MFTA were significantly decreased (P < 0.05), and the clinical and functional scores were significantly increased (P < 0.05) in the combined treatment group.

CONCLUSION

3D printed osteotomy guide plate-assisted TKA for valgus knee deformity is more effective than TKA alone.

Medial femoral epicondyle upsliding osteotomy with posterior stabilized arthroplasty provided good clinical outcomes such as constrained arthroplasty in primary total knee arthroplasty with severe valgus deformity

PURPOSE

A modified technique referred to as a medial femoral epicondyle upsliding osteotomy was proposed to address severe valgus deformity with unconstrained posterior stabilized (PS) arthroplasty. The study compared the effectiveness of the technique and PS arthroplasty with constrained arthroplasty during primary total knee arthroplasty (TKA).

METHODS

Fifty-three patients presenting with valgus knees with a mean valgus angle (VA) greater than 30° were prospectively randomized and divided into two groups, and both groups received primary TKA. Upsliding osteotomy with PS arthroplasty was performed on the knees of 27 patients (group A), while the remaining 26 patients (group B) received a constrained arthroplasty. The Knee Society function score (KSF), Hospital for Special Surgery knee score (HSS), range of motion (ROM), mediolateral stability and hospitalization expenses were recorded. The hip-knee-ankle angle (HKA), femorotibial angle (FTA) and VA were analysed. Complications were also recorded.

RESULTS

The patients received follow-up care for more than 50 months. The postoperative KSF, HSS and ROM showed marked improvement in both groups (p < 0.05). Radiological assessments showed that HKA, FTA and VA for group A were restored to (179.9 ± 3.0)°, (173.0 ± 2.4)° and (7.0 ± 2.4)°, respectively. For group B, the HKA, FTA and VA were restored to (181.5 ± 2.3)°, (172.5 ± 2.3)° and (7.5 ± 2.3)°, respectively. Only two patients from group A demonstrated mild medial laxity in their knees, and the remaining patients from both groups were stable medially and laterally. However, the total hospitalization expenses and material expenses of group A were less than those of group B because of the more expensive constrained prosthesis and stems. No late-onset loosening or recurrent valgus deformity was displayed.

CONCLUSIONS

Both medial femoral epicondyle upsliding osteotomy with PS arthroplasty and constrained arthroplasty showed good outcomes for the restoration of neutral limb alignment and soft tissue balance, which are demonstrated to be safe and effective techniques for correcting severely valgus knees. Therefore, the clinically important finding of this study is that medial femoral epicondyle upsliding osteotomy with PS arthroplasty can be an alternative method for correcting severe valgus knees.

LEVEL OF EVIDENCE

II.

Total knee arthroplasty for a valgus deformity angle of >90°: A case report

RATIONALE

Valgus knees are relatively rare in the clinic. Treatments for valgus deviations >90° represent a surgical challenge to achieve a balance between the soft tissue and bone and prevent nerve damage.

PATIENT CONCERNS

A 63-year-old woman with valgus deviations >90° in both knees complained that she had been unable to walk for 50 years.

DIAGNOSES

Congenital malformation valgus deformity.

INTERVENTIONS

Bilateral total knee arthroplasty (TKA) was performed using a rotating hinge knee instrument from Endo-Model for axial correction and stabilization of the joint.

OUTCOMES

The patient fully recovered 3 months after surgery. At the follow-up 6 years after the operation, the function of the knee joint clearly improved. The knee society score (KSS) increased from 35 to 90.

LESSONS

Constrained implants are commonly used to stabilize the joint and correct the bone axis in patients with severe ligamental instability, gross deformity, bone loss, and extreme deviation of the straight leg axis. Intraoperative exploration of the common peroneal nerve and the postoperative flexed position of the knee joints could help prevent nerve injuries.

Under-corrected knees do not fail more than aligned knees at 8 years in fixed severe valgus total knee replacement

PURPOSES

A fixed severe valgus knee is a surgical challenge. A safe post-operative Hip-Knee-Ankle angle (HKA) range of 180° ± 4 was recommended, but recent studies mentioned equal results from outliers of this range. Nevertheless, no distinction was made between varus and valgus knees, as well as over-corrected or under-corrected knees. Did post-operative nonaligned total knee replacements (TKR) from fixed severe valgus knees behave differently from the properly aligned population? Did over-corrected knees behave differently from under-corrected knees?

METHODS

Through a multi-center retrospective cohort study, we provided 557 knees of at least 10° of minimal pre-operative valgus; in this population 75 presented a post-operative Hip-Knee-Ankle angle (HKA) outside of the 180° ± 4 range; 23 of them had at least 5° of varus; 52 of them had at least 5° of valgus. Median pre-operative HKA of the entire cohort was 194° (range 190-198). Median follow-up was 8 years (range 5-11); Knee Society Score (KSS) results, HKA, Femoral and Tibial Mechanical Angles (FMA, TMA) and complication rates were obtained. The outlier group (HKA ≤ 175 or ≥ 185) was compared to the control group (HKA 180 ± 4); over-corrected (HKA ≤ 175) and under-corrected (HKA ≥ 185) sub-groups were individually tested against the control group.

RESULTS

The outlier group had a lower Final Knee Score than the aligned group (p = 0.023). In the over-corrected sub-group, median post-operative FMA was 88° (SD 4°) and median TMA was 87° (SD 4°). The complication rate was higher (p = 0.019). Knee (p = 0.018), Function (p = 0.034) and Final Knee Scores (p = 0.03) were statistically lower than in the control group. In the under-corrected sub-group, mean post-operative FMA was 93° (SD 2°) and mean TMA was 91° (SD 2°). The complication rate was lower (p = 0.019) and there was no difference with the control group concerning KSS.

CONCLUSIONS

In case of pre-operative fixed severe valgus knee, one should avoid over-correcting HKA angle and especially the TMA. Over-correction of a severe preoperative valgus in a post-operative varus was prejudicial for TKA survival. Keeping a severe valgus knee in low valgus to avoid using a more constrained implant and/or ligament releases will not decrease the 5-10 year implant survival and functional scores.

LEVEL OF EVIDENCE

Level IV-Case series.

The Effectiveness of Medial Femoral Epicondyle Up-Sliding Osteotomy to Correct Severe Valgus Deformity in Primary Total Knee Arthroplasty

BACKGROUND

While many surgical techniques can achieve neutral limb alignment and soft tissue balance in severe valgus deformity during total knee arthroplasty (TKA), few published reports concern medial femoral epicondyle up-sliding osteotomy.

METHODS

A prospective investigation was conducted of patients with severe valgus deformities who underwent medial femoral epicondyle up-sliding osteotomy. Clinical measurements, radiological evaluation, and complication data were recorded.

RESULTS

Using posterior-stabilized prostheses, 26 patients underwent 28 TKAs performed by the same surgeon using medial femoral epicondyle up-sliding osteotomy to balance the soft tissue. On average, the follow-up was 54 ± 18 months, and the patient age was 63 ± 11 years. All knees were type II according to Krackow's classification. Varus-valgus knee motion was prohibited with the protection of long-leg knee brace for 3 months. At the last follow-up, the Knee Society function score, Hospital for Special Surgery knee-rating scale, and range of motion were 94 ± 6, 91 ± 4, and 116° ± 8°, respectively. All knees were stable laterally, whereas 2 knees had mild medial laxity and the others were stable. The hip-knee-ankle angle, femorotibial angle, condylar-hip angle, plateau-ankle angle, and valgus angle were 179.9° ± 3.4°, 172.9° ± 3.6°, 89.8° ± 2.5°, 90.2° ± 1.1°, and 7.3° ± 3.5°, respectively.

CONCLUSION

Medial femoral epicondyle up-sliding osteotomy during TKA in patients with severe valgus deformities facilitates the restoration of lower limb alignment, soft tissue balance, and knee stability.

Soft Tissue Releases in Total Knee Arthroplasty for Valgus Deformities

BACKGROUND

Primary total knee arthroplasty (TKA) for valgus knee deformities can be challenging. Soft tissue releases are often necessary to achieve a well-balanced knee. We reviewed the frequency of soft tissue releases including lateral retinacular release (LRR) as it pertains to preoperative limb alignment. Postoperatively, we evaluated limb alignment, knee range of motion, and complications.

METHODS

From 2010 to 2016, 214 primary TKAs with valgus deformity were performed by a single surgeon. One hundred eighty-one patients had an average follow-up of 24 months. For these patients, clinical data including preoperative and postoperative range of motion, complications, and revision rates were collected. Soft tissue releases, preoperative and postoperative limb axis deviation, and level of prosthetic constraint were recorded in all patients regardless of length of follow-up.

RESULTS

There were 33 knees (15%) that required 1 release, 69 knees (32%) required 2 releases, 81 knees (38%) required 3 releases, and 31 knees (14%) that required 4 or more releases. The average preoperative mechanical axis was 9.4°, and the average postoperative mechanical axis was 0.13°. There were 85 knees (40%) that required an LRR. Increased severity of preoperative deformity correlated with the need for more soft tissue release, but did not correlate with the need for LRR. No knees were revised for instability. No patella complications resulted from LRR.

CONCLUSION

Selective soft tissue release for primary valgus TKA was effective without increasing prosthetic constraint. Severe deformities required more soft tissue releases. LRR can be frequently used with minimal complications.

Management of severe valgus knee by total unconstrained arthroplasty: A comparative study with long-term follow-up

OBJECTIVE

To evaluate the use of unconstrained implants in the correction of large valgus deformities using total knee arthroplasty (TKA).

MATERIAL AND METHOD

A total of 817 primary TKA operated between 1998 and 2006 were retrospectively assessed. 50 TKA were selected (group A) in 49 patients, with a minimum deformity of 15° of valgus, 41 cases were included. Another 50 ATR were selected (group B), with a maximum deformity of 15° of varus, finally including 44 cases in 42 patients. The same surgeon performed every operation. The minimum follow-up time was 10 years. The Knee Society Score (KS and FS), the Oxford Knee Score (OKS) and the Range of Mobility (ROM), both preoperative and postoperative at 1,.5 and 10 years, as well as radiographic evolution and complications were evaluated.

RESULTS

Preoperative values of KS, FS and OKS were lower in group A (P<.0001, P<.01 and P<.05, respectively), but not ROM. Postoperatively, KS, FS, OKS and ROM were not different between the groups, neither year, nor 5, nor 10 years. There were also no radiological or complications between the two groups.

DISCUSSION

The use of non-constricted implants in severe valgus was not inferior to the mild varus, implying, in addition, a saving in economic terms, with excellent postoperative results.

CONCLUSIONS

Correction of severe valgus deformities can be performed with non-constrained primary implants, without obtaining worse results than those obtained in mild deformities.

Does low-constraint mobile bearing knee prosthesis give satisfactory results for severe coronal deformities? A five to twelve year follow up study

PURPOSE

Severe varus and valgus knee deformities traditionally are replaced with constrained implants, with a number of disadvantages. We present our results in this challenging group using a low constraint deep-dish mobile bearing implant design.

METHODS

One hundred fifty-four patients (170 arthroplasties) who underwent primary TKA using a deep-dish, mobile bearing posterior-stabilized implant for severe varus (HKA < 170°) or valgus (HKA > 190°) deformity between 2004 and 2009 were evaluated at a mean of 6.6 years post-operatively (minimum of 5 years).

RESULTS

Alignment improved from a pre-operative mean (±SD) varus deformity of 167.4° (±2.6°) and a mean (±SD) valgus deformity of 194.1° (±4.0°) to an overall mean (±SD) post-operative mechanical alignment of 178.6° (±3.2°). Twenty-three patients had post-operative varus alignment, five patients had post-operative valgus alignment and 134 knees were in neutral alignment (within 3° spread). Clinical scores at final follow-up were excellent (IKS score 93.8 (±7.4) and function score 82.4 (±20.2)). Three patients were re-operated upon: one deep infection, one periprosthetic fracture and one revision at 144 months for aseptic loosening of the femoral component. No patient was revised for instability or implant failure. The survival rate at five years was 99.4% and at ten years 98.6%.

CONCLUSIONS

Satisfactory outcomes can be achieved in patients with substantial varus or valgus deformities using low constraint deep-dish mobile bearing implant, standard approach and appropriate soft tissue releases.

Correcting severe valgus deformity: taking out the knock

Valgus knee deformity can present a number of unique surgical challenges for the total knee arthroplasty (TKA) surgeon. Understanding the typical patterns of bone and soft-tissue pathology in the valgus arthritic knee is critical for appropriate surgical planning. This review aims to provide the knee arthroplasty surgeon with an understanding of surgical management strategies for the treatment of valgus knee arthritis. Lateral femoral and tibial deficiencies, contracted lateral soft tissues, attenuated medial soft tissues, and multiplanar deformities may all be present in the valgus arthritic knee. A number of classifications have been reported in order to guide surgical management, and a variety of surgical strategies have been described with satisfactory clinical results. Depending on the severity of the deformity, a variety of TKA implant designs may be appropriate for use. Regardless of an operating surgeon's preferred surgical strategy, adherence to a step-wise approach to deformity correction is advised. Cite this article: Bone Joint J 2017;99-B(1 Supple A):60-4.

Total knee arthroplasty for valgus osteoarthritis: the results of a standardized soft-tissue release technique

PURPOSE

The study reports the 2-year follow-up results of patients with valgus osteoarthritis undergoing total knee arthroplasty (TKA) with a standardized soft-tissue release.

METHODS

Between 2008 and 2013, 222 TKAs were performed for valgus osteoarthritis by a single surgeon. A total of 181 TKAs in 164 patients were available for a minimum 2-year follow-up (range 24-87 months). Preoperative and postoperative range of motion (ROM), mechanical alignment, the postoperative medial proximal tibial angle (MPTA), Western Ontario and McMaster Universities Arthritis Index (WOMAC), VF-12 score, visual analogue pain scale (VAS), and the actual UCLA activity score, desired UCLA score, ligamentous stability (medial collateral ligament) and complications and revision rates were recorded.

RESULTS

The ROM increased from a preoperative flexion contracture of 4.7° (range 0-40) and flexion of 110° (range 35-135) to a postoperative mean flexion contracture of 0.1° (range -5 to 10) and flexion of 128° (range 100-140). The mean hip-knee-ankle alignment was changed from 8.4° of mechanical valgus (range 5.3-25.4) to 0.02° of varus alignment (range -2.9 to 4.1). Tibia component angle (MPTA) was 90.4° (range 86.1-93.7). The WOMAC score, VF-12, UCLA and VAS significantly improved after surgery (p < 0.05). Two patients (1.1 %) underwent revision surgery for instability.

CONCLUSION

The described standardized soft-tissue release (release of the iliotibial band and posterolateral corner) provided excellent clinical results at a minimum 2-year follow-up and can be used safely for a "cook-book" approach to the valgus knee with up to 25° mechanical valgus alignment.

LEVEL OF EVIDENCE

IV.