Correction of varus deformity during TKA with reduction osteotomy

Medial osteophyte resection width correlates with correction of the medio-lateral component gap imbalance during posterior-stabilized total knee arthroplasty

BACKGROUND

There is a lack of robust evidence for a correlation between the medial osteophyte resection and correction of the medio-lateral gap imbalance during total knee arthroplasty. The purpose of the present study was to quantify the effect of osteophyte resection on the medio-lateral component gap imbalance during posterior-stabilized total knee arthroplasty.

METHODS

Forty-five cases of primary posterior-stabilized total knee arthroplasty using the measured resection technique with posterior-stabilized prosthesis for varus knee osteoarthritis were reviewed. Medial and lateral joint gaps at 0°, 10°, 45°, and 90° of flexion, and maximum flexion were measured intraoperatively before and after the osteophyte resection. The relationship between medial osteophyte resection width and change of joint varus angle and medial component gap were assessed using Pearson's correlation coefficient.

FINDINGS

Medial component gap and joint varus angle values at post medial osteophyte resection were significantly larger and lower than at pre-resection (Medial gap: pre 9.5 ± 1.8 mm, post 10.3 ± 1.8 mm, P < 0.001, Joint angle: pre 5.2 ± 2.9°, post 4.2 ± 2.9°, P < 0.001). There was no significant difference between pre and post medial osteophyte resection in lateral component gaps. Per each 1 mm of medial osteophyte resection width, increases of 0.13 mm medial component gap and 0.2° valgus were observed (Medial gap: r = 0.38, P < 0.001, Joint angle: r = 0.38, P < 0.001).

INTERPRETATION

Medial osteophyte resection increases the medial component gap without lateral component gap increase, while decreasing the joint varus angle in primary posterior-stabilized total knee arthroplasty for varus knee osteoarthritis. Osteophyte resection width was found to correlate with correction of the medio-lateral component gap imbalance.

Medial proximal tibial resorption after total knee arthroplasty according to the design of the cobalt chrome tibial baseplate

PURPOSE

A new tibial baseplate of the cobalt-chrome (CoCr) prosthesis has an enhanced design with additional cement pockets and undersurface with increased roughness compared with the original baseplate. This study aimed to compare the incidence of medial proximal tibial resorption (MPTR) in total knee arthroplasties (TKAs) with the original and new CoCr tibial baseplates.

METHODS

Each of 200 posterior stabilized TKAs with the original (Group O) and new (Group N) CoCr tibial baseplates with a minimum follow-up period of 2 years were retrospectively reviewed. The matches were made according to age, sex, body mass index, and severity of varus deformity. The occurrence of MPTR was investigated with a radiograph at 2 years postoperatively. MPTR was categorized as type U (resorption under the tibial baseplate; associated with stress shielding), C (resorption around the penetrated cement under the baseplate; associated with thermal necrosis), and M (resorption on the medial tibial cortex without extension to the baseplate; associated with bony devascularization).

RESULTS

The incidence of MPTR was 35% in group O and 24% in group N (p = 0.021) at postoperative 2 years. The U type of MPTR occurred more frequently in group O (26 vs. 15%, p = 0.009). There were no significant differences in the incidence of types C and M MPTR.

CONCLUSION

The modified design of the CoCr tibial baseplate affected the incidence of MTPR. The new tibial baseplate was more advantageous in preventing MPTR than the original baseplate in TKAs using the CoCr prosthesis.

LEVEL OF EVIDENCE

III.

Osteotomies and Total Knee Arthroplasty: Systematic Review and Meta-Analysis

Total knee replacement (TKA) is a frequent modality performed in patients with osteoarthritis. Specific circumstances can make it much more difficult to execute successfully, and additional procedures such as osteotomy may be required. The aim of this study was to perform a meta-analysis and systematic review of osteotomies combined with TKA. Methods: In June 2022, a search PubMed, Embase, Cochrane, and Clinicaltrials was undertaken, adhering to PRISMA guidelines. The search included the terms “osteotomy” and “total knee arthroplasty”. Results: Two subgroups (tibial tubercle osteotomy and medial femoral condyle osteotomy) were included in the meta-analysis. Further subgroups were described as a narrative review. The primary outcome showed no significant difference in favor to TTO. Secondary outcomes showed improved results in all presented subgroups compared to preoperative status. Conclusion: This study showed a significant deficit of randomized control trials treated with osteotomies, in addition to TKA, and a lack of evidence-based surgical guidelines for the treatment of patients with OA in special conditions: posttraumatic deformities, stiff knee, severe varus, and valgus axis or patella disorders.

Total Knee Arthroplasty Using Adjusted Restricted Kinematic Alignment for the Treatment of Severe Varus Deformity: Technical Note

Objective

To describe a new alignment technique of adjusted restricted kinematic alignment (arKA) for the treatment of severe varus deformity in total knee arthroplasty.

Methods

Three female patients (three severe varus knees) who underwent navigation‐assisted total knee arthroplasty (TKA) using arKA from April 2020 to September 2020 were included in this study, with an average age of 71.33 years (range, 61 to 80 years). General anesthesia was given to all patients. Intraoperative observations including tibia resection angle, frontal femoral angle, axial femoral angle, medial and lateral gap in the extension and flexion positions and joint line translation were recorded. Also, operation duration and drainage volume were recorded. Radiographic parameters including the mechanical axis (α), coronal femoral component angle (β), coronal tibial component angle (γ), sagittal femoral component angle (δ), tibial posterior slope angle (ε), femoral‐patella angle (θ), and femoral notching were assessed. Clinical evaluation was performed using the Hospital for Special Surgery (HSS) Score and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Score. Both individual and mean measurement data were displayed.

Results

The mean tibial resection was 4.00° varus (range, 3° to 5°), and the mean frontal femoral angle was 3.67° varus (range, 3° to 4°) in extension. The flexion lateral gap was wider than the medial gap with a mean laxity of 1.34 mm. Moreover, the mean axial femoral angle was 2.67° external (range, 0° to 6°) in flexion, and the mean joint line translation was 1.00 mm proximal (range, 0 to 3 mm). In addition, the mean preoperative mechanical axis was 156.22° (range, 153.65° to 158.90°) and the mean postoperative mechanical axis was 174.04° (range, 173.83° to 174.17°) with a mean correction of 17.82°. The mean femoral angle was 92.60° (range, 91.29° to 93.30°) and the mean tibial angle was 86.95° (range, 86.83° to 87.04°) in coronal plane. The HSS score improved from an average of 46.67 points (range, 42 to 51) preoperatively to 83.67 points (range, 81 to 86) at 3 months postoperatively. The mean WOMAC score was 16.33 points at 3 months postoperatively.

Conclusions

The new alignment technique of arKA aims to balance the flexion and extension gap without extensive releases of soft tissue and restore the native pre‐arthritic alignment, may be a promising alignment strategy for treating severe varus deformity. However, further study and comparison with other alignment techniques is needed.

Navigation and robotics improved alignment compared with PSI and conventional instrument, while clinical outcomes were similar in TKA: a network meta-analysis

PURPOSE

To achieve the desired alignment more accurately and improve postoperative outcomes, new techniques such as computer navigation (Navigation), patient-specific instruments (PSI) and surgical robots (Robot) are applied in Total Knee Arthroplasty (TKA). This network meta-analysis aims to compare the radiological and clinical outcomes among the above-mentioned techniques and conventional instruments (CON).

METHODS

A PRISMA network meta-analysis was conducted and study protocol was published online at INPLASY (INPLASY202060018). Three databases (PubMed, EMBASE and Cochrane) were searched up to June 1, 2020. Randomised controlled trials (RCTs) comparing any two of the four techniques were included. A Bayesian network meta-analysis was performed focusing on radiological and clinical outcomes. The odds ratio (OR) or mean difference (MD) in various outcomes were calculated, and the interventions were ranked by the surface under the cumulative ranking area (SUCRA) value.

RESULTS

Seventy-three RCTs were included, with a total of 4209 TKAs. Navigation and Robot could significantly reduce the occurrence of malalignment and malposition compared with PSI and CON, and Navigation could obtain higher medium-and-long-term KSS knee scores than CON. Robot had the greatest advantage in achieving the desired alignment accurately, followed by Navigation; Navigation had the greatest advantage in the KSS score.

CONCLUSION

Navigation and Robot did improve the accuracy of alignment compared with PSI and conventional instrument in TKA, but the above four techniques showed no clinical significance in postoperative outcomes.

LEVEL OF EVIDENCE

I.

Posterior Cruciate Ligament Resection and Varus Correction in Total Knee Arthroplasty: A Study Using Computer-Assisted Surgery

Background

Methods

Results

Conclusion

Registration of Proximal Tibial Centre May Need to be Selectively Lateralized to Avoid Coronal Malalignment in Digitally-Assisted Knee Arthroplasty

PURPOSE

Placement of prosthetic components and limb alignment can be adversely impacted by errors in identification of registration points in digitally assisted knee arthroplasty. The purpose of this study was to trigonometrically analyze the impact on the accuracy of coronal tibial component and limb alignment of discrepancy between the registered midpoint of the proximal bony tibia vis-à-vis the radiographic medio-lateral center of the lateralized final tibial implant in certain varus-deformed knees.

METHODS

We analyzed trigonometrically the angular difference θ in coronal alignment of tibial component and hip-knee-ankle angle resulting from lateral translation of the medio-lateral center of the final tibial implant, with respect to the initial registered midpoint of the proximal bony tibia. θ was calculated using the equation tan( θ ) = d/t, where d is the numerical distance between the registered point and the center of the final tibial tray position and t is the length of tibia distal to the resection.

RESULTS

One degree of varus malpositioning of the tibial component and the limb can occur for every 6.3 mm of lateral translation of the tibial implant with respect to the midpoint of the proximal bony tibia of average reported length (372 mm). The magnitude of this error is inversely proportional to tibial length and the patient's height.

CONCLUSIONS

Coronal malalignment of the tibial component and the limb is directly proportional to the amount of lateral translation of the tibial tray with respect to the registered midpoint of the proximal bony tibia and inversely proportional to the patient's height. This may occur in cases with tibial extra-articular deformity, those undergoing reduction osteotomy, downsizing of the tray, or inadvertently during tibial preparation. The error can be avoided by initial registration of the tibial midpoint more laterally by templating, re-registering the new center of the resected tibial surface or osteotomy for extra-articular deformity.

The relationship between severity of varus osteoarthritic knees and contracture of the medial structures

BACKGROUND

Severe varus osteoarthritic knee has possibility of medial structure contracture. There is no report concerning the relationship between severity of varus deformity and contracture of medial structure. We aimed to reveal a threshold angle that could be corrected in proportion to the width of medial osteophyte removal, and to examine correction differences between larger and smaller than the threshold angle in total knee arthroplasty.

METHODS

This study included 27 varus osteoarthritic knees scheduled for total knee arthroplasty (TKA). Each knee was measured the hip-knee-ankle angles (HKA) using a navigation system, at maximum extension, 30˚ and 60˚ flexion before and after osteophyte removal, with and without external 10 N-m valgus torque loads. Subsequently, resected osteophyte widths were measured. Mean correction angle per 1 mm osteophyte removal was calculated, and the threshold angle was calculated using the receiver operating characteristic curve. HKA differences were compared against larger and smaller deformity than the threshold angle.

RESULTS

Mean osteophyte width was 7.1±2.20 mm. Osteophyte removal produced a mean 3.1° correction, which equaled a 0.4° correction per 1 mm osteophyte width removal. The varus deformity threshold angle was 9.5°, however, when comparing the groups larger and smaller than the threshold, there were no significant differences in HKA differences between each step and flexion angle.

CONCLUSIONS

The threshold angle for expected correction with medial osteophyte removal was 9.5˚. However, with no differences in correction between those with larger or smaller than this angle, medial structure contracture seemed to be unrelated to severity of deformity.

Posteromedial Corner Release with the Knee in Figure-of-Four Position vs Conventional Position for Varus Knee Arthroplasty

OBJECTIVE

To introduce posteromedial corner release with the knee in the figure-of-four position versus the conventional position for varus knee arthroplasty.

METHODS

This is a retrospective study. From March 2015 to September 2019, a series of 123 patients (139 knees) with varus knee were randomly and blindly allocated to experimental group (60 patients; 68 knees) and control group (57 patients; 65 knees). Patients in experimental group underwent posteromedial corner release with the knee in the figure-of-four position; and patients in control group with the knee in the conventional position. If soft tissue balance was not completely achieved or the medial gap was still tight, an additional loosening technique were used to achieve symmetric medial and lateral space in both groups. Time for soft tissue balancing was defined as the time from the start of the spacer test to the end of the balance test. Length of release was defined as the distance from the osteotomy surface of the tibial plateau to the farthest structures released. The rating system of Hospital for Special Surgery (HSS) knee score was used to evaluate the clinical results. Quantitative variables were described as mean and standard deviation, and compared by one-way analysis of variance.

RESULTS

The mean age of experimental group and control group was 70.2 ± 8.7 years and 68.7 ± 6.2 years, respectively (P > 0.05). Preoperatively, the mean HSS score of the groups was 38.2 ± 11.3 and 39.1 ± 10.7, respectively (P > 0.05). The mean varus knee angle was 19.7° ± 9.3° and 19.3° ± 10.7°, respectively (P > 0.05). The mean time for soft tissue balancing was 8.4 ± 3.3 min and 11.3 ± 6.9 min in experimental and control group, respectively (P < 0.05). The mean length of releasing posteromedial corner structures was 35.5 ± 13.4 mm and 27.3 ± 9.7 mm in experimental and control group, respectively (P < 0.05). Additional special loosening techniques were performed in eight knees in experimental group and seven knees in control group. The HSS scores 5 years after surgery were 95.1 ± 16.9 and 94.8 ± 17.2 respectively (P > 0.05). No complications were found during the follow-up time, and the clinical symptoms were observed to be significantly improved in the patients.

CONCLUSION

The posteromedial corner can be released more extensively and thoroughly when the knee is placed in the figure-of-four position during varus knee arthroplasty.

The medial gap is a reliable indicator for intraoperative soft tissue balancing in posterior-stabilized total knee arthroplasty

BACKGROUND

Appropriate soft tissue balance and accurate alignment are important for successful total knee arthroplasty (TKA). However, the optimal technique for establishing and measuring soft tissue balancing remains unclear. The aim of this study was to analyze the intraoperative medial and lateral gap pattern using digital knee balancer in posterior-stabilized (PS) TKA.

METHODS

This study involved 55 patients with medial osteoarthritis who underwent a primary TKA using an image-free navigation system. The extension gap and the flexion gap at 90° knee flexion were assessed using an offset seesaw-type digital balancer. Continuous joint distraction force from 10 lb to 60 lb was applied. Medial gap, lateral gap, and varus angle were measured.

RESULTS

The medial bone gap difference between extension and flexion was constant regardless of the distraction force from 20 lb to 60 lb. The lateral bone gap was significantly greater than the medial bone gap in extension and flexion from 30 lb to 60 lb (P < 0.05). The varus angle changed depending on the distraction force, especially in flexion. The varus angle in flexion was significantly greater than that in extension from 40 lb to 60 lb (P < 0.05).

CONCLUSIONS

The medial bone gap is a reliable indicator unaffected by the distraction force during surgery and is useful for adjusting the medial gap in extension and flexion appropriately to ensure medial stability in PS-TKA. The digital knee balancer and navigation system support both precise gap assessment and surgery.

Proximal tibia vara involves the medial shift of the tibial articular surface

PURPOSE

According to the concept of the constitutional varus, the tibial articular surface (TAS) has varus inclination. On the other hand, it has been reported that proximal tibia vara involved medial shift of the TAS. However, it has not been assessed whether varus inclination of the TAS has a correlation with the medial shift. We investigated whether varus inclination of the TAS has a correlation with the medial shift. If there is a correlation between two parameters, the influence of the medial shift of the TAS on the value of the hip-knee-ankle (HKA) angle and the femorotibial angle should be considered.

METHODS

A total of 112 patients who underwent total knee arthroplasty had anteroposterior view tibia digital radiograph on which five parameters were analyzed. Varus angle of the TAS, the distance between the mechanical axis and the anatomical axis on the articular surface, and the width of the articular surface were measured.

RESULTS

The more the proximal tibia had varus deformity, the more the TAS shift medially would be. Therefore, the mechanical axis does not match the anatomical axis. Because the HKA angle was assessed based on the concept that the mechanical and anatomical axes match on the tibia, this angle may not express the true alignment of the lower extremity in knees with proximal tibia vara.

CONCLUSION

In varus knees, the proximal tibia has a medial shift of the TAS that may influence the value of the HKA angle.

Proximal fibular resection improves knee biomechanics and enhances tibial stress fracture healing in patients with osteoarthritis with varus deformity: a prospective, randomized control analysis

Background

The present study aimed to evaluate the functional outcome of single-stage total knee arthroplasty using long-stem tibial component with proximal fibular resection (PFR) for patients with knee osteoarthritis with varus deformity associated with tibial stress fracture.

Method

A cohort of 62 patients with a mean age 71.63 ± 7.40 years who met the criteria were randomized to a study group and a control group. Patients in the study group underwent single-stage total knee arthroplasty using long-stem tibial component with PFR. The control group received conventional treatment. All patients were followed at 1, 3, 6 and 12 month(s) after surgery. Standard anteroposterior and lateral weight bearing knee X-rays were analyzed. Western Ontario and Mc-master Universities Osteoarthritis Index score (WOMAC) and the visual analog scale (VAS) score were used to assess the functional outcome. The level of significance was set at p < 0.05 levels.

Results

One patient in the study group was lost to follow-up, leaving 61 patients for final assessment. The WOMAC total score and mean VAS score were significantly better in study group than in control group at final follow-up (p < 0.05). All fractures were successfully united in a mean time of 12.26 ± 1.20 weeks in study group. A total of 16 patients in control group had delayed union, five had established nonunion and required further interventions. No complications relating to surgery was detected.

Conclusion

Total knee arthroplasty with PFR for knee arthritis with varus deformity associated with tibial stress fractures restores limb alignment, improves biomechanics, enhances fracture healing and provides excellent functional outcome.

The Medial Collateral Ligament in Primary Total Knee Arthroplasty: Anatomy, Biomechanics, and Injury

Understanding the anatomy and biomechanics of the medial collateral ligament (MCL) is crucial in producing good outcomes after total knee arthroplasty. A solid grasp of the surgical techniques that address the MCL are necessary to ensure good coronal plane ligament balance. Furthermore, intraoperative injury to the MCL in total knee arthroplasty is an uncommon yet serious complication which often goes unrecognized. Loss of the integrity of the MCL can lead to instability, loosening, and accelerated polyethylene wear. There is still controversy regarding the ideal method of treatment of intraoperative MCL injuries with suggested treatment modalities ranging from conservative management to use of varus-valgus constrained implants.

Can isolated removal of osteophytes achieve correction of varus deformity and gap-balance in computer-assisted total knee arthroplasty?

AIMS

The aims of this study were to determine the effect of osteophyte excision on deformity correction and soft tissue gap balance in varus knees undergoing computer-assisted total knee arthroplasty (TKA).

METHODS

A total of 492 consecutive, cemented, cruciate-substituting TKAs performed for varus osteoarthritis were studied. After exposure and excision of both cruciates and menisci, it was noted from operative records the corrective interventions performed in each case. Knees in which no releases after the initial exposure, those which had only osteophyte excision, and those in which further interventions were performed were identified. From recorded navigation data, coronal and sagittal limb alignment, knee flexion range, and medial and lateral gap distances in maximum knee extension and 90° knee flexion with maximal varus and valgus stresses, were established, initially after exposure and excision of both cruciate ligaments, and then also at trialling. Knees were defined as 'aligned' if the hip-knee-ankle axis was between 177° and 180°, (0° to 3° varus) and 'balanced' if medial and lateral gaps in extension and at 90° flexion were within 2 mm of each other.

RESULTS

Of 50 knees (10%) with no soft tissue releases (other than cruciate ligaments), 90% were aligned, 81% were balanced, and 73% were aligned and balanced. In 288 knees (59%) only osteophyte excision was performed by subperiosteally releasing the deep medial collateral ligament. Of these, 98% were aligned, 80% were balanced, and 79% were aligned and balanced. In 154 knees (31%), additional procedures were performed (reduction osteotomy, posterior capsular release, and semimembranosus release). Of these, 89% were aligned, 68% were balanced, and 66% were aligned and balanced. The superficial medial collateral ligament was not released in any case.

CONCLUSION

Two-thirds of all knees could be aligned and balanced with release of the cruciate ligaments alone and excision of osteophytes. Excision of osteophytes can be a useful step towards achieving deformity correction and gap balance without having to resort to soft tissue release in varus knees while maintaining classical coronal and sagittal alignment of components. Cite this article: Bone Joint J 2020;102-B(6 Supple A):49-58.

Effect of Medial Osteophyte Removal on Correction of Varus Deformity in Total Knee Arthroplasty

BACKGROUND

To restore neutral limb alignment in total knee arthroplasty (TKA), the procedure usually starts with removing osteophytes in varus osteoarthritic knees. However, the exact effect on alignment correction is unknown. The purpose of this study was to determine the effect of osteophyte removal alone during TKA for varus knees on correction of limb alignment on the coronal plane.

METHODS

Fifteen knees with medial osteoarthritis and varus malalignment scheduled for TKA were studied. After registration in a navigation system, each knee was tested at maximum extension, and at 30, 40, and 60 degrees of flexion, before and after osteophyte removal. External loads of 10 N·m valgus torque at each angle and in both states were applied. Later, the widths of the resected osteophytes were measured.

RESULTS

The average preoperative hip-knee-ankle angle was -14.2 degrees. The average width of osteophytes was 7.6 mm in the femur and 5.3 mm in the tibia. Angle corrections after osteophyte removal were 3.4 degrees at maximum extension, 3.4 degrees at 30 degrees flexion, and 3.6 degrees at 60 degrees flexion; the difference was significant for all angles. There was a positive correlation between osteophyte width and the degree of angle correction at 30 degrees.

CONCLUSION

At 30 degrees of knee flexion, osteophyte width was correlated with the degree of angle correction on the coronal plane in TKA. The degree of angle correction per 1 mm of width of removed osteophytes was 0.4 degrees.

Using Tibia Proximal Cut Autograft in Advanced Varus Knee Deformity in Total Knee Arthroplasty; Outcomes Compared to the Control Group

Background:

The purpose of this study was to compare the outcomes of Total Knee Arthroplasty (TKA) performed for advanced varus knee deformity, which is performed by using tibia proximal cut bone for the reconstruction of the tibia proximal medial bone defects, with a control group consisting of TKAs which did not need reconstruction.

Methods:

Patients in the present study underwent total knee arthroplasty between 2009 and 2015. 12 patients with advanced varus deformity who had undergone reconstruction with tibia proximal cut autograft and 15 patients who were randomly selected from patients who did not need reconstruction, were compared clinically and radiographically.

Results:

The mean follow-up period of the patients was found to be 73.1 ± 19.7 (36-108) months in the reconstruction group and 73.2 ± 12.3 (39-107) months in the control group. (p> 0.05) In both groups, significant improvement was observed postoperatively. In both groups, there was no evidence of loosening the required revision. WOMAC score was 32.4 ± 13.3 (8-64) in the reconstruction group and 28.9 ± 17.2 (6-70) in the control group at the last control visit. There was no difference between the groups when comparing the WOMAC scores at the last control visit. In the reconstruction group, the Hip-Knee-Ankle (HKA) angle was 26.1 ± 4.9 ° varus preoperatively and 1.3 ± 2.3 ° valgus postoperatively; and in the control group 10.1 ± 2.1 ° varus preoperatively and 2.7 ± 3.4 ° valgus postoperatively. (p> 0.05)

Conclusion:

In the present study, clinical and radiographic results of total knee arthroplasty patients, who suffered from advanced knee varus deformity and whose proximal tibia medial defects were reconstructed by using tibial proximal cut autograft, have been found to be successful when compared to the control group.

Total knee arthroplasty in the varus knee: tips and tricks

Varus knee deformity is very common, and it can be classified according to the severity and reducibility of the deformity. Pre-operative planning is mandatory to obtain a good result. Both clinical and radiological planning should be carefully performed, particularly focused on collateral ligament deficiency. In most of the cases, a postero-stabilized implant is necessary, but in the presence of a varus thrust, a midlevel constrained (MLC) implant may be necessary. Rarely, if a severe extra-articular deformity is present, a femoral osteotomy and a high constrain implant may be necessary. In most of the cases, a standard midline approach can be performed. Soft tissue balancing is crucial, avoiding excessive releases of the medial collateral ligament (MCL). In the presence of severe deformity, more aggressive procedure such as tibial reduction osteotomy or sliding medial epicondyle osteotomy can be performed. In literature, good outcomes are reported for total knee arthroplasty (TKA) in varus deformity. In this manuscript, the available literature on TKA in varus deformity is analyzed, and the preferred surgical techniques of the authors are described.

Selective medial soft tissue release combined with tibial reduction osteotomy in total knee arthroplasty

BACKGROUND

To obtain the correct coronal alignment and balancing in flexion and extension, we established a selective medial release technique and investigated the effectiveness and safety of the technique during primary total knee arthroplasty (TKA).

METHODS

Four hundred sixty-six primary TKAs with varus deformity were prospectively evaluated between June 2013 and June 2015. A knee joint position similar to Patrick's sign was used to release the medial structure. The medial release technique consisted of release of the capsule and the deep medial collateral ligament (dMCL) (step1), selective release of superficial medial collateral ligament (sMCL) or posterior oblique ligament (POL) (step 2), and selective tibial reduction osteotomy (step 3). Improvement of medial joint gap at each step and other clinical outcomes were evaluated.

RESULTS

Among the 466 knees, symmetrical gaps could be achieved by the limited release of the capsule and the dMCcL in 276 (59%) knees. One hundred fifty-two (33%) required additional sMCL release with 2-5 cm from the joint line distally or POL release. Thirty-eight (8%) necessitated an additional tibial reduction osteotomy. Anterior-medial release and 4-mm medial osteotomy contributed to more improvement of medial gap in flexion than in extension (each p < 0.01). Posteromedial release and posteromedial osteotomy contributed to more improvement in extension than in flexion (each p < 0.01). No specific complication related to our technique was identified.

CONCLUSION

The technique of the tibial reduction osteotomy combined with medial soft structure release using Patrick's sign is effective, safe, and minimally invasive to obtain balanced mediolateral and extension-flexion gaps in primary TKA.

Reduction Osteotomy versus Extensive Release on Clinical Outcome Measures in Simultaneous Bilateral Total Knee Arthroplasty

Background

During total knee arthroplasty (TKA) in varus knee deformities, reduction osteotomy (RO) and medial soft tissue release are alternative techniques to aid in achieving deformity correction. In this study, we investigated the effect of RO compared to extensive medial soft tissue release (ER) on clinical outcome measures in simultaneous bilateral TKA.

Material/Methods

We prospectively enrolled 24 patients (48 knees) with bilateral varus knee deformity from July 2014 to December 20l5. For each patient, one knee was assigned to the RO group and the contralateral knee was assigned to ER group. One year postoperative, follow-up outcomes were collected and analyzed.

Results

Time to 90° flexion of the knee was significantly different in the RO group (1.6±0.3 days) compared to the ER group (2.0±0.4 days) (p<0.001). Using a 10-item patient reported outcome questionnaire, total scores were significantly different between the RO group (86.3±3.2) and the ER group (82.4±2.7) (p<0.001). Analysis of variance showed a significant difference on the visual analogue scale (VAS) score (p<0.001) but no significant difference in the range of motion (ROM) of the knee (p>0.05) during the follow-up year.

Conclusions

Knees treated with RO were associated with greater improvements in pain and function than knees treated with conventional ER technique. Additionally, RO technique did not confer an increased risk for adverse clinical outcomes. RO may therefore by a safe method to decrease postoperative pain, achieve earlier functional recovery, and increase patients’ subjective satisfaction after TKA.

Concurrent femoral and tibial osteotomies versus soft tissue balance in total knee arthroplasty: A technical case report

This case report outlines some of the challenges as well as limitations in correction of osteoarthritis of the knee in combination with extra-articular deformities,and provides a novel and straightforward surgical solution in overcoming these challenges. We describe the case of a 37-year-old male who suffered from advanced bilateral tri-compartmental knee arthritis due to untreated bloodstream-sourced osteomyelitis after birth. Radiographs and surgery confirmed extremely severe deformities. We performed two different surgical techniques in order to correct extra-articular deformities (one-stage approach of concurrent tibial and femoral osteotomy and total knee arthroplasty on one side, and soft tissue balancing with "pie-crusting technique" plus total knee arthroplasty on the other side), with description of subsequent results at 36-months follow-up.

Reduction Osteotomy vs Pie-Crust Technique as Possible Alternatives for Medial Release in Total Knee Arthroplasty and Compared in a Prospective Randomized Controlled Trial

BACKGROUND

To compare the gap change between the pie-crust technique and reduction osteotomy to determine their effects on flexion and extension gaps and their success rates in achieving ligament balancing during total knee arthroplasty.

METHODS

In a prospective randomized controlled trial, 106 total knee arthroplasties were allocated to each group with 53 cases. If there was a narrow medial gap with an imbalance of ≥3 mm after the initial limited medial release, either reduction osteotomy or pie-crust technique was performed. The changes of extension and flexion medial gaps along with the success rate of mediolateral balancing were compared.

RESULTS

There was a significant difference in the change of medial gap in knee extension with mean changes of 3.5 ± 0.5 mm and 2.3 ± 0.8 mm in the reduction osteotomy and pie-crust groups, respectively (P < .001). For flexion gap, greater change was found in the pie-crust group compared with the reduction osteotomy group; the mean medial gap changes in knee flexion were 1.1 ± 0.5 mm and 2.3 ± 1.2 mm in the reduction osteotomy and pie-crust groups, respectively. The success rates were 90.6% and 67.9% in reduction osteotomy and pie-crust groups, respectively (P = .007).

CONCLUSION

As an alternative medial release method, reduction osteotomy was more effective in extension gap balancing, and pie-crust technique was more effective in flexion gap balancing. The overall success rate of mediolateral ligament balancing was higher in the reduction osteotomy group than in the pie-crust group.

Correcting deformity in total knee arthroplasty

Collateral ligament release is advocated in total knee arthroplasty (TKA) to deal with significant coronal plane deformities, but is also associated with significant disadvantages.

We describe steps to avoid release of the collateral (superficial medial and lateral collateral) ligaments during TKA in severely deformed knees, while correcting deformity and balancing the knee.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):101–4.

Effects of Reduction Osteotomy on Gap Balancing During Total Knee Arthroplasty for Severe Varus Deformity

This study aimed to assess the effects of down-sizing and lateralizing of the tibial component (reduction osteotomy) on gap balancing in TKA, and the clinical feasibility of an uncemented modular trabecular metal tibial tray in this technique. Reduction osteotomy was performed for 39 knees of 36 patients with knee OA with a mean tibiofemoral angle of 21° varus. In 20 knees, appropriate gap balance was achieved by release of the deep medial collateral ligament alone. Flexion gap imbalance could be reduced by approximately 1.7° and 2.8° for 4-mm osteotomy and 8-mm osteotomy, respectively. Within the first postoperative year, clinically-stable tibial component subsidence was observed in 9 knees, but it was not progressive, and the clinical results were excellent at a mean follow-up of 3.3 years.

Varus-valgus stress radiograph as a predictor for extensive medial release in total knee arthroplasty

PURPOSE

The purpose of this study was to identify the risk factors for predicting the reduction osteotomy as extensive medial release during total knee arthroplasty (TKA) using multivariate logistic regression.

METHODS

A total of 404 TKAs were enrolled and sorted into two groups according to the extent of medial release and then analysed for the statistical significance of various risk factors including age, gender, body mass index (BMI), pre-operative knee mechanical axis angle (KMAA), mechanical varus stress angle (MVrSA), mechanical valgus stress angle (MVgSA), and sum of the mechanical varus and valgus stress angles (SMVVA) with use of multivariate logistic regression analysis.

RESULTS

SMVVA to a more varus direction was found to be a significant risk factor for the reduction osteotomy (p < 0.0001, adjusted odds ratio (OR) = 2.705 with 95 % CI 2.126-3.443). KMAA and MVgSA to a more varus direction were also significant risk factors (p = 0.010, adjusted OR = 1.189 with 95 % CI 1.041-1.357, and p = 0.005, adjusted OR = 1.401 with 95 % CI 1.109-1.767). The other variables were not significant risk factors.

CONCLUSIONS

The overall results suggest that careful attention should be given to the need for extensive medial release and failure of the conventional soft tissue release technique during TKA in patients with a greater varus angle in the pre-operative SMVVA, MVgSA, and KMAA, especially with a greater varus SMVVA, which was the strongest predictor of reduction osteotomy.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Medial over-resection of the tibia in total knee arthroplasty for varus deformity using computer navigation

We are reporting a series of 35 cases in which downsizing, lateralizing of the tibial baseplate and resection of the uncovered medial plateau bone releases the medial collateral ligament and tightens the lateral collateral ligament. Result in excellent ligamentous balance and correction to neutral mechanical axis. The mean follow up was 32.8 months (11-95 months) and the average pre-operative varus was 9.47° (3.5-15°) with the average post-operative alignment was 0.65° varus. We obtained a mean correction of 0.45° for every mm (millimeter) of bone resected. We did not have any varus collapse or instability. Medial Over-resection could be employed as a technique in the management of varus OA knee with 2mm of resection giving about 10 correction of deformity.