Total knee arthroplasty in the valgus knee. Int Orthop. 2014;38:273-283. [PMID: 24366186 DOI: 10.1007/s00264-013-2227-4]

Proposal of a New Reference Point to Determine the Tibial Resection Depth during Total Knee Arthroplasty for Valgus Knees

The tibial resection depth during total knee arthroplasty for valgus knees has been variously described and not been standardized yet. Accordingly, it has been proposed in this article, that the sulcus between the medial and lateral intercondylar tibial tubercles can be used as a reference point for the tibial resection depth. The resection can be performed 8 to 9 mm distal to the sulcus.

Is varus-valgus constraint a reliable option in complex primary total knee arthroplasty? A systematic review

PURPOSE

Knee instability is considered one of the most frequent cause of failure after primary total knee arthroplasty (TKA). In order to address intraoperative instability, varus-valgus constrained knee implants (VVC) are increasingly utilized in primary TKA. Despite an increased risk of mechanical failure, short to mid-term results seem to be encouraging, but long-term results are still lacking.

METHODS

A systematic review of prospective and retrospective studies that reported clinical outcomes of patients with VVC systems in primary TKAs between 1990 and 2020 was performed.

RESULTS

In all, 28 articles met our inclusion criteria. A total of 2798 VVC implants were used in primary TKA. The all-cause revision-free survivorship was 95.2% at a mean follow-up of 7 years. Infection and aseptic loosening were the most common reasons for reoperation with an incidence of 1.8% and 1.7%, respectively. Overall complication rate was 9.6%, the most common complications were knee stiffness and infection with an incidence of 2.8% and 2.5%, respectively.

CONCLUSIONS

VVC implants in primary TKA are associated with improved functional outcomes and good mid-term survivorship, comparable to lower level of constraint implants. Non-modular stemless seem to be reliable implants at mid-term follow-up. However, given the lack data coming from long-term studies, VVC implants should be used cautiously in primary TKA.

High Medium-Term Survivorship of Cruciate-Retaining Total Knee Arthroplasties (110 Knees) for Valgus Deformity

The main purpose of this article is to evaluate the clinical outcomes and survivorship of cruciate-retaining (CR) knee arthroplasties for valgus deformity. This article is retrospective consecutive series of 110 valgus knees using CR implants with a minimum 2-year follow-up. Deformity correction was achieved using stepwise sequential soft tissue releases (iliotibial band, popliteus tendon, lateral collateral release through sliver femoral condylar osteotomy). Demographic data, range of movement, and degrees of deformity were collected. The Oxford Knee Score (OKS) was used as patients' reported outcome measure at final follow-up. One-hundred and four patients (110 knees) were included (87 females/17 males) with mean age of 68.7 years. Primary diagnosis was osteoarthritis in 85 patients and rheumatoid arthritis in 19 patients. Mean follow-up was 5.5 years (median: 5 years; range: 2-14 years). Preoperative valgus deformity was measured radiographically using the mechanical tibiofemoral angle with a mean 18.6° (standard deviation [SD]: 7.5; range: 11-38°). At final follow-up, mechanical tibiofemoral angle was 3.8° (SD: 1.97; range: 2-8°). A p-value was <0.0001 and mean OKS was 42 (SD: 5.4; range: 36-48) suggesting satisfactory patients' reported outcomes with no implant revision for any cause. CR implants for valgus knees using staged soft tissue releases including sliver condylar osteotomy had excellent medium-term survivorship and satisfactory patient reported outcome measures. The Level of Evidence for this study is IV.

Higher revision rate for posterior cruciate-retaining than posterior-stabilized total knee arthroplasty for the treatment of valgus osteoarthritis

PURPOSE

Determining the point at which a valgus deformity requires a more invasive therapy-in this case PS TKA-is surgically challenging. Retaining the posterior cruciate ligament has both advantages and disadvantages. The aim was to evaluate the failure rate and clinical outcomes.

METHODS

248 patients with valgus gonarthrosis underwent surgical treatment: 167 CR TKA cases and 81 PS TKA cases. The KOOS and the OKS were recorded, and 201 patients (133 CR, 68 PS) were recruited into the retrospective study. The influence of BMI and degree of preoperative valgus deformity on the clinical outcome was determined. The revision rate was documented and analysed.

RESULTS

Of 201 patients, 10 required revision surgery owing to instability (10/133 CR, 0/68 PS). Based on the KOOS and the OKS, no significant difference between CR TKA and PS TKA was found. BMI and degree of valgus deformity had no effect on the clinical outcome.

CONCLUSIONS

No difference in the clinical outcome between the CR and PS TKA patients was found. In the CR group, significantly more patients showed 'excellent' OKS than in the PS group. However, 8.0% of the patients in the CR group and none in the PS group underwent surgery due to instability. A higher rate of dissatisfied patients in the CR group is likely. In our clinic, we no longer perform CR TKA for valgus cases.

A cruciate-retaining implant can treat both knees of most windswept deformities when performed with calipered kinematically aligned TKA

PURPOSE

Surgeons performing total knee arthroplasty (TKA) on the osteoarthritic valgus deformity often use a posterior stabilized (PS) and semi-constrained implants to substitute for the release of a contracted posterior cruciate ligament (PCL) instead of a cruciate retaining (CR) implant. Calipered kinematic alignment (KA) strives to retain the PCL and use a CR implant. The aim of this study of the windswept deformity was to determine whether the level of implant constraint, outcome scores, and alignment after bilateral calipered KA TKA are different between a pair of knees with a varus and valgus deformity in the same patient.

METHODS

A review of a prospectively collected database identified all patients with a windswept deformity treated with bilateral TKA (n = 19) out of 2430 consecutive primary TKAs performed between 2014 and 2019. Operative reports determined the level of implant constraint. Patient response to the Forgotten Joint Score (FJS) and Oxford Knee Score (OKS) assessed outcomes at a mean follow-up of 2.3 years. Postoperative alignment was measured on an A-P computer tomographic scanogram of the limb.

RESULTS

CR implants were used in 15 of 19 (79%) valgus deformities and 17 of 19 (89%) of varus deformities (n.s.). No knees required a semi-constrained implant. There was no difference in the median postoperative FJS and OKS (n.s.), and a 1° or less difference in the mean postoperative distal lateral femoral angle (p = 0.005) and proximal medial tibial angle (n.s.) between the paired varus and valgus knee deformity.

CONCLUSION

Based on this small series, surgeons that use calipered KA TKA can expect to use CR implants in most patients with windswept deformity and achieve comparable outcome scores and alignment between the paired varus and valgus deformity.

LEVEL OF EVIDENCE

IV.

Rotational kinematics differ between mild and severe valgus knees in total knee arthroplasty

BACKGROUND

There is no consensus regarding femorotibial rotational kinematics in total knee arthroplasty (TKA) for valgus knee deformity. Additionally, whether the degree of valgus deformity influences intraoperative rotational kinematics and postoperative clinical scores remains unclear. The objectives of this study were to investigate whether the valgus angle is associated with intraoperative rotational kinematics in TKA for valgus knee deformity and to examine the relationship between rotational kinematics and postoperative clinical results.

MATERIALS AND METHODS

A total of 24 knees with valgus deformity for TKA were included in this study and were divided into two groups depending on the femorotibial angle (FTA); there were 11 knees in the severe valgus group (FTA < 160°) and 13 knees in the mild valgus group (FTA ≥ 160°). Intraoperative femorotibial rotational kinematics from knee extension to flexion were evaluated using an image-free navigation system and postoperative clinical results (range of motion and subjective outcomes) were evaluated 1 year postoperatively. All parameters were compared between the two groups.

RESULT

Mild valgus knee showed tibial internal rotation during knee flexion before implantation, whereas severe valgus knee showed tibial external rotation during knee flexion before implantation. The postoperative flexion angle was positively correlated with the tibial internal rotation angle after implantation in the mild valgus group only.

CONCLUSION

Intraoperative rotational kinematics before implantation differed between mild and severe valgus knee deformity in TKA. Intraoperative tibial rotation influenced the postoperative knee flexion angle in mild, but not severe, valgus knee deformity. Ideal postoperative rotational kinematics may be different between the two groups and the difference may be taken into consideration in implant selections and surgical techniques.

Total knee arthroplasty with the least-constrained implant possible for type II valgus knee > 20°: a 3–14 years’ follow-up

Objective

To estimate the midterm outcome of primary total knee arthroplasty for severe valgus deformity using selective release of tight lateral structures and the least-constrained implant.

Methods

We performed total knee arthroplasty on 65 consecutive type II knees with valgus deformity> 20°. Surgery was done via a medial parapatellar approach. Conventional bone cutting was done with selective lateral soft tissue release, and the least-constrained total knee prosthesis possible was used. Posterior stabilized implants were employed in most knees, except for three knees that required the implantation of constrained condylar knee prostheses. The average duration of follow-up lasted for 10.5 years.

Results

Preoperatively, average valgus was 30.6°, and average range of motion was 43.7° (range, 0–80°). Postoperatively, average valgus was 7.3° and average range of motion was 110.6° (range, 80–130°). The lateral collateral ligament and iliotibial band were released in all knees, and release of the popliteus tendon was required in two knees. Stable flexion and extension gaps were achieved in most cases, except for two that had medial side instability. Follow-up showed that stability was maintained.

Conclusions

This surgical technique combined selective lateral soft tissue release with use of the least-constrained implant possible and was effective for severe valgus deformities of the knee, with good clinical results.

A lateral parapatellar approach with iliotibial band dissection from the Gerdy tubercle for total knee arthroplasty of the valgus knee

Valgus knee, which causes severe dysfunction and seriously affects the quality of life of patients, is a condition affecting 10% of patients who undergo total knee arthroplasty (TKA). The best choice of surgical approach and the method of release of soft tissue, however, is still unclear. Therefore, the aim of the present study was to investigate the clinical efficacy of a lateral parapatellar approach with iliotibial band (ITB) dissection from the Gerdy tubercle for TKA in valgus knees. In total, 56 patients (25 males and 31 females) who underwent surgery via a lateral parapatellar approach with ITB dissection from the Gerdy tubercle for TKA due to valgus knee, with at least one-year follow-up, were retrospectively analyzed. Operation duration, length of time leg was raised post-surgery, prosthetic position, lower limb force line, visual analogue score for pain (VAS), range of movement (ROM), and Knee Society Scores (KSS; including knee score and functional score) were reviewed and analyzed. The data indicated that VAS, ROM and KSS were significantly improved after surgery compared with those before surgery. Additionally, no patient had a deviation in prosthetic position or limb alignment greater than 5˚. These results suggest that a lateral parapatellar approach with ITB dissection from the Gerdy tubercle for TKA is an effective technique to treat valgus knee, which can significantly improve pain and function without deviation of the lower limb mechanical axis or prosthesis position.

Incidence of Soft-Tissue Releases, Clinical and Radiological Outcomes of Lateral Parapatellar Approach for Valgus Arthritic Knees: A 4-year Follow-up Study with A Review of Literature

PURPOSE

To analyse the incidence of additional soft tissue releases with the lateral parapatellar approach, and the clinical and radiological outcomes of total knee arthroplasties performed using the lateral parapatellar approach for valgus arthritic knees. A review of the existing literature on valgus arthritic knees undergoing knee replacement was performed and our results compared.

MATERIALS AND METHODS

This is a prospective cohort study of 50 patients operated by this approach. Operation and clinical records were assessed to determine the number and sequence of soft tissue releases. Functional outcome was measured using the Oxford Knee Score. Radiological assessment included measurement of alignment and implant positioning.

RESULTS

46 patients included. Mean follow-up of 4 years. Additional lateral releases were performed in 11 (24%) cases. Mean valgus alignment corrected from 13.1 degrees pre-operatively to 5.7 degrees post-operatively. Oxford Knee Score improved from a mean pre-operative score of 11.9 to a mean post-operative score of 38.3 at final follow-up. Radiographs revealed lateralisation of the tibial component in 4 patients. No immediate or late post-operative wound complications, late instabilities or revisions were observed.

CONCLUSION

Lateral parapatellar approach is highly effective in correcting the valgus deformity with a low incidence of additional soft tissue releases. Medium-term results indicate an excellent functional outcome with no complications.

The influence of femoral and tibial bony anatomy on valgus OA of the knee

PURPOSE

Approximately 10% of all patients that require a total knee arthroplasty present with valgus osteoarthritis (OA) of the knee. Valgus OA goes along with posterolateral bone loss and lateral soft tissue tightness. The role of malalignment on the development of OA is not fully understood. The current study investigates whether the femoral offset (FO), femoral mechanical-anatomical (FMA) angle, anatomical lateral distal femur angle (aLDFA), mechanical lateral distal femur angle (mLDFA), medial proximal femur angle (MPFA), medial proximal tibia angle (MPTA) or lateral distal tibia angle (LDTA) differ in patients with valgus OA of the knee.

METHODS

FO, FMA angle, aLDFA, mLDFA, MPFA, MPTA and LDTA were assessed and compared between 100 consecutive knees with minimal valgus OA (50 male, 50 female) and 100 consecutive knees with minimal varus OA (50 male, 50 female).

RESULTS

FO was significantly higher in males with valgus OA (p = 0.002) and females with varus OA (p = 0.01). The observed values for the FMA angle were significantly higher in males with valgus OA (p = 0.002) and females with varus OA (p = 0.041). The aLDFA and mLDFA were significantly smaller in all patients with valgus OA (p < 0.001). No differences between the varus and valgus groups were detected regarding MPFA (males: p = 0.052; females: p = 0.719). Tibial measurements showed significantly higher values for the MPTA (p < 0.001) in both valgus groups and no difference for LDTA (men: p = 0.139; women: p = 0.196).

CONCLUSION

Bony alterations in the femoral anatomy seem to be more important than in the tibial anatomy. While in male patients with valgus OA, the main anatomic variation is the hypoplasia of the lateral femoral condyle, in females both decreased femoral offset of the hip as well as hypoplasia of the lateral condyle are present.

LEVEL OF EVIDENCE

III.

Lateral subvastus approach: A cadaveric examination of its potential for total knee arthroplasty

BACKGROUND

Lateral approaches to total knee arthroplasty (TKA) provide good surgical exposure and may provide greater ease of soft tissue balancing in patients with a valgus deformity; however, little is known about the versatility in non-valgus knees. The present study evaluated if a lateral subvastus approach can achieve adequate surgical exposure while maintaining less soft tissue damage compared with the medial parapatellar approach in knees without any significant deformity.

METHODS

Using paired fresh-frozen cadaveric knees, the present study provides the first specimen-matched, side-by-side comparison of the lateral subvastus approach to the standard medial parapatellar approach to TKA. Ten knees were selected to undergo a lateral subvastus approach; the contralateral knee had a medial parapatellar approach as control. Incision length, surgical exposure and iatrogenic soft tissue damage were compared between the two approaches.

RESULTS

The lateral subvastus approach was successfully performed using an incision length that was not different from that used in the medial parapatellar approach (p > 0.05). The resultant surgical exposure was comparable between approaches (p > 0.05). The risk of the approach included tearing of the vastus lateralis fibers, and/or abrasion of the iliotibial tract/patellar ligament.

CONCLUSIONS

The lateral subvastus approach to TKA provided a comparable method to the standard medial parapatellar approach. Despite adequate exposure, the approach did risk soft tissue injury. Caution needs to be exercised to reduce the risk of iatrogenic injury to the vastus lateralis and surrounding ligaments. The successful implementation in this cadaveric study substantiates the need for further consideration of this approach in clinical practice.

The effect of patellar facet angle on patellofemoral alignment and arthritis progression in posterior-stabilized total knee arthroplasty without patellar resurfacing

Background

The purpose of this study was to evaluate the effect of patellar facet angle on pre- and postoperative patellofemoral alignment and the progress of arthritis of the patellofemoral joint in posterior-stabilized total knee arthroplasty (PS TKA) without patellar resurfacing.

Methods

Patients who had a PS TKA for a varus osteoarthritic knee who were followed up for more than 2 years were included in this study. The radiologic and clinical outcomes were compared between 72 knees (group A) whose patellar facet angle was greater than 126° (> 126°) and 32 knees (group B) whose patellar facet angle was smaller than or equal to 126° (≤ 126°). For the radiologic assessment, the Kellgren-Lawrence grade, mechanical femorotibial angle, Insall-Salvati ratio, patellar tilt angle, patellar displacement and the osteosclerosis of the patellar ridge were evaluated. The range of motion (ROM) and patient-reported outcomes (the Knee Society knee score, the Knee Society function score, the Feller patellar score, and the Kujala patellofemoral score) were used for the clinical assessment.

Results

The preoperative patellar tilt angle was 9.8° (standard deviation [SD] 5.5) and 14.6° (SD 4.1) in group A and group B, respectively, a significant difference (p < 0.001). Other preoperative radiologic parameters and preoperative patient-reported outcomes and ROM showed no significant difference between the two groups (all parameters (p > 0.05). At the last-follow-up, 22 knees (30.6%) showed progression of osteosclerosis of the patellar ridge in group A and 13 knees (40.6%) showed progression of osteosclerosis in group B (p = 0.371). The postoperative radiologic and clinical outcomes showed no significant difference between the two groups (all parameters, p > 0.05).

Conclusions

Although a narrow patellar facet angle was related to an increase of lateral tilting of the patella, it showed no impact on the preoperative clinical assessment. The radiologic and clinical outcomes evaluated after the PS TKA showed no statistical difference according to the patellar shape. Although the patellar shape evaluated by the patellar facet angle can partially affect the preoperative patellofemoral alignment, this study result indicated insignificant clinical relevance of the patellar shape in the PS TKA.

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.

Satisfactory medium-term outcomes with lateral condylar sliver osteotomy to correct valgus deformity in total knee replacements

PURPOSE

To describe a surgical technique in correcting valgus deformity during total knee replacement and evaluate medium-term clinical outcomes.

METHODS

This was a retrospective consecutive series of total knee replacement for severe valgus deformity of patients who underwent a lateral ligament complex release with a sliver osteotomy of the lateral femoral condyle with a minimum 1-year follow-up and recording objective and patient-reported outcome measures.

RESULTS

Twenty-three patients (25 knees) were included with median follow-up of 5 years (range 1-15 years) and average age 67.7 years (range 43-87). The primary diagnosis was osteoarthritis in 14 patients (61%) and inflammatory arthritis in 9 patients (39%). At final follow-up, the median mechanical tibiofemoral angle was restored to 4° (range 2-7) compared with a median valgus of 20° (range 13-30) preoperatively. This was statistically significant (P < 0.00001). Median Oxford Knee Score at final follow-up was 43 (range 36-48) indicating satisfactory outcomes. There were no revisions for any cause with a mean arc range of movement 110° (range 85-120).

CONCLUSION

This study shows that a technique utilising the familiar medial parapatellar approach, staged soft tissue releases, and a novel sliver lateral femoral condylar osteotomy with intact periosteum to release the lateral ligament complex leads to satisfactory medium-term outcomes, improved range of movement and patients' reported outcome measures. Sliver osteotomy is a useful technique in correcting valgus deformity in total knee replacements at medium-term follow-up.

LEVEL OF EVIDENCE

IV.

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.

The effects of soft tissue lateral release on the stability of the ligament complex of the knee

PURPOSE

Valgus deformity presents a particular challenge in total knee arthroplasty. This condition regularly leads to contractures of the lateral capsular ligament complex and to overstretching of the medial ligamentous complex. Reconstruction of the knee joint kinematics and anatomy often requires lateral release. However, data on how such release weakens the stability of the knee are missing in the literature. This study investigated the effects of sequential lateral release on the collateral stability of the ligament complex of the knee in vitro.

METHODS

Ten knee prostheses were implanted in 10 healthy cadaveric knee joints using a navigation device. Soft tissue lateral release consisted of five release steps, and stiffness and stability were determined at 0, 30, 60 and 90° flexion after each step.

RESULTS

Soft tissue lateral release increasingly weakened the ligament complex of the lateral compartment. Because of the large muscular parts, the release of the iliotibial band and the M. popliteus had little effect on the stability of the lateral and medial compartment, but release of the lateral ligament significantly decreased the stability in the lateral compartment over the entire range of motion. Stability in the medial compartment was hardly affected. Conversely, further release of the posterolateral capsule and the posterior cruciate ligament led to the loss of stability in the lateral compartment only in deep flexion, whereas stability decreased significantly in the medial compartment.

CONCLUSION

Our study shows for the first time the association between sequential lateral release and stability of the ligamentous complex of the knee. To maintain the stability, knee surgeons should avoid releasing the entire lateral collateral ligament, which would significantly decrease stability in the lateral compartment.

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.

Lateral or medial approach for valgus knee in total knee arthroplasty - which one is better? A systematic review

Objective

To identify whether the medial or lateral approach is superior for patients with valgus knees undergoing primary total knee arthroplasty (TKA).

Methods

Studies evaluating the 2 approaches were sourced from the PUBMED, EMBASE, Web of Science, and OVID databases. The quality of included studies was assessed using a modified quality evaluation method, and differences between approaches were systematically reviewed.

Results

Seventeen observational studies were included. The studies were published between 1991 and 2016, and included 5 retrospective studies and 12 prospective studies. Sixteen evaluation methods for the study outcomes were identified. Twelve and eight complication types were identified by studies reporting the lateral and medial approaches for valgus knee, respectively. Several studies showed that pain scores and knee function were superior using a lateral approach.

Conclusion

The lateral approach (combined with a tibial tubercle osteotomy or proximal quadriceps snip) was more useful and safer than the medial approach in the treatment of severe uncorrectable valgus knee deformity in patients undergoing TKA. Most of the available evidence supports the use of a lateral approach provided that the surgeon is familiar with the pathological anatomy of the valgus knee.

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.

Medium-term follow-up of 149 mobile-bearing total knee arthroplasties and evaluation of prognostic factors influencing outcomes

OBJECTIVE

To evaluate the medium-term outcomes of a posterior-stabilized mobile-bearing total knee arthroplasty (PS-MB-TKA) and the role of different prognostic factors.

METHODS

Patients indicated for a primary cemented PS-MB-TKA between 2002 and 2010 were included and prospectively evaluated using the Knee Society Scoring System (KSS) and the Hospital for Special Surgery (HSS) knee scores. The Knee Society Roentgenographic Evaluation form was used for the radiological evaluation. Different variables were collected and divided into patient- and surgery-related. Logistic regression was used to analyze the correlation between these variables and implants outcomes and survivorship.

RESULTS

In total, 149 cases were included (67.8% female, average age 70.4 years, SD ±9.4). The patella was resurfaced in 12.1% of the cases. All the implants were cemented. The average follow-up was 87.3 months (SD ±21.2). Postoperatively, there was a statistically significant improvement in all the scores. The cumulative survival was 96.2% (SD ±0.02%). At the regression analysis, female gender was associated to worse satisfaction KSS (OR = 0.26), functional KSS (OR = 0.22), and HSS (OR = 0.37) scores. Patellar resurfacing and subsequent contralateral procedures were associated to better functional KSS score (OR = 4.13, OR = 2.21), as well as varus preoperative alignment (OR = 2.12). On contrary, valgus preoperative alignment was associated to worse objective KSS score (OR = 0.23). No variables were correlated to failure or presence of radiolucent lines.

CONCLUSION

Good medium-term outcomes were obtained using PS-MB-TKA, with a cumulative survivorship of 96.5%. Female gender and valgus preoperative alignment were associated to worse objective and subjective outcomes. Conversely, patellar replacement, subsequent contralateral TKA, and varus preoperative alignment were associated to better functional outcomes.

Preoperative valgus deformity has twice the risk of failure as compared to varus deformity after total knee arthroplasty

PURPOSE

The aim of this study was to assess whether preoperative valgus or varus deformity affected survivorship after total knee arthroplasty (TKA) and to quantify the risk factors for implant failure in a registry-based population.

METHODS

The Emilia-Romagna Registry of Prosthetic Orthopedic Implants was examined regarding TKAs performed on patients with a preoperative diagnosis of valgus or varus deformity. Demographics, implant characteristic and survivorships were investigated and compared. A total of 2327 TKA procedures performed from 2000 to 2016 were included in the study. Six hundred and forty primary TKAs with a diagnosis of valgus deformity were evaluated with a median follow-up of 3.3 years; 1687 primary TKAs with a diagnosis of varus deformity were evaluated with a median follow-up of 2.5 years.

RESULTS

Bi-compartmental, cemented posterior stabilised fixed-bearing implants were preferred. For both diagnoses, the implant survivorship rate was greater than 98% in the first year. However, the survival curve of the TKAs implanted for valgus deformity showed a greater slope in the first 3 years as compared to the survival curve of those implanted for varus deformity. Valgus deformity had a 2.1-fold higher risk for revision as compared with varus deformity. Infection was a major cause of implant failure in TKAs for varus deformity, 9/24 (37.5%), while its incidence was lower for valgus deformity, 1/21 (4.8%).

CONCLUSIONS

Preoperative valgus alignment showed a twofold risk of failure as compared to varus alignment after TKA. This should be considered in daily practice, and surgeons are called on to pay more attention when performing TKAs on such patients. Prospective randomised controlled trials are, therefore, necessary to better understand the role of preoperative coronal knee deformity in implant failure.

LEVEL OF EVIDENCE

Prognostic study, level III.

Valgus position of the femoral component causes abnormal kinematics in the presence of medial looseness in total knee arthroplasty: a computer simulation model of TKA for valgus knee osteoarthritis

PURPOSE

Total knee arthroplasty (TKA) for valgus knee osteoarthritis is challenging. Although overcorrection in TKA for valgus knee osteoarthritis is recommended, supportive data based on biomechanics have rarely been reported. The purpose of this study was to elucidate whether coronal rotation of the femoral compartment causes abnormal kinematics with or without medial looseness.

METHODS

Multi- and single-radius posterior-stabilised TKA implants were utilised in a computer simulation. A total of 4 mm of slack were provided in the medial collateral ligament (MCL) with varus or valgus position of the femoral component to simulate the context of valgus knee osteoarthritis. Kinematics during gait and squatting activities were evaluated in each condition.

RESULTS

During squatting, medial looseness and valgus replacement caused anterior translation of the medial femoral component in mid-flexion in the multi-radius implant. In the worst condition (7° valgus replacement with MCL looseness), there was rapid anterior translation in the multi-radius implant, and moderate anterior translation in the single-radius implant. Although medial looseness alone did not cause abnormal kinematics during gait, the worst condition exhibited an anterior translation to 4.9 mm in the multi-radius implant. This worst condition also exhibited a marked lift-off of 8.0 and 2.9 mm in the multi- and single-radius implants, respectively. Varus position caused little abnormal kinematics even with MCL looseness.

CONCLUSION

Valgus, not varus position of the femoral component caused abnormal kinematics with MCL looseness. To avoid valgus position, the safety target angle of femoral component would be slight varus rather than neutral in valgus knee OA.

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.

Clinical spectrum of neuropathy after primary total knee arthroplasty: A series of 54 cases

INTRODUCTION

Neuropathy after total knee arthroplasty (TKA) can cause significant morbidity but is inconsistently reported.

METHODS

We reviewed the clinical, electrodiagnostic and perioperative features of all patients who underwent primary TKA at our institution and developed a new neuropathy within 8 weeks postoperatively.

RESULTS

Fifty-four cases were identified (incidence 0.37% [95% confidence interval, 0.28-0.49]) affecting the following nerve(s): peroneal (37), sciatic (11), ulnar (2), tibial (2), sural (1), and lumbosacral plexus (1). In all cases with follow-up data, motor recovery typically occurred within 1 year and was complete or near-complete.

CONCLUSIONS

Post-TKA neuropathy is uncommon, typically does not require intervention and usually resolves within 1 year. Post-TKA neuropathy most often affects the nerves surgically at risk. Anesthesia type does not correlate with post-TKA neuropathy. An inflammatory etiology for post-TKA neuropathy is rare but should be considered in specific cases. Muscle Nerve 59:679-682, 2019.

Navigation-Assisted Total Knee Arthroplasty for a Valgus Knee Improves Limb and Femoral Component Alignment

The purpose of this study was to evaluate the influence of navigation-assisted surgery on radiographic and clinical outcomes after total knee arthroplasty (TKA) for a valgus knee. The authors identified all patients who underwent TKA for a valgus knee between January 2005 and December 2015. Among 83 conventional TKA cases and 55 navigation-assisted TKA cases, propensity score matching was performed for age, sex, body mass index, and preoperative lower limb mechanical axis. Fifty knees were matched to 50 knees. Each case was evaluated regarding lower limb mechanical axis, mechanical lateral distal femoral angle, medial proximal tibial angle, patellar tilt angle, Western Ontario and McMaster Universities Osteoarthritis Index, Knee Society score, and range of motion. Lower outliers of lower limb mechanical axis (30% vs 8%, P=.008) and mechanical lateral distal femoral angle (24% vs 10%, P=.046) were found in navigation-assisted TKA. However, outliers of medial proximal tibial angle, Western Ontario and McMaster Universities Osteoarthritis Index, Knee Society score, and range of motion were similar between the 2 different surgical techniques. Navigation-assisted surgery is correlated with fewer outliers of postoperative lower limb alignment and femoral component position but not tibial component position in TKA for preoperative valgus knee. Clinical outcomes for navigation-assisted TKA were not superior to those for conventional TKA. [Orthopedics. 2019; 42(2):e253-e259.].

Rotational Shortening of Collateral Ligament in TKR With Severe Deformity

Instability of the knee joint after total knee replacement (TKR) is one of the most important reasons for revision TKR. Inadequate release or tightening of the collateral ligaments in the knee joint may cause instability and early failure. This study presents a case series study of a new technique for ligament balancing wherein the collateral ligament is detached from its origin and rotated (twisted) around its longitudinal axis to tighten the ligament before the origin is reattached to its original position. The surgical technique for collateral ligament tightening during TKR was performed on 6 patients with a deformed knee caused by osteoarthritis and rheumatoid arthritis. The range of motion, knee society score, and laxity of the patients' knee joint, after 7 months to 13 years of follow-up, were evaluated. The technique was successful, achieving good range of motion and satisfactory stability of the joint. Further evaluation in a larger number of cases and a comparative analysis with different techniques would further support the usefulness of this rotational ligamentoplasty technique.

Relationship Between Coronal Alignment and Rotational Profile of Lower Extremity in Patients With Knee Osteoarthritis

BACKGROUND

We aimed at determining whether the coronal alignment of lower extremity was related to rotational geometry of distal femur, femoral anteversion, and tibial torsion in patients with knee osteoarthritis.

METHODS

A total of 422 lower extremities were divided into 3 groups according to the coronal alignment: valgus (n = 31), neutral (n = 78), and varus group (n = 313). Condylar twisting angle was measured to determine rotational geometry of distal femur as the angle between the clinical transepicondylar axis and the posterior condylar line. Femoral anteversion was assessed using the angle between a line intersecting the femoral neck and the posterior condylar line (pFeAV) and the angle between the same line and transepicondylar axis that is not affected by posterior condylar variations (tFeAV). Tibial torsion was evaluated by measuring the angle between the posterior condyles of the proximal tibia and the transmalleolar axis.

RESULTS

As the coronal alignment changed from varus to valgus, the condylar twisting angle increased (r = 0.253, P < .001; 6.6° in varus, 7.4° in neutral, and 10.2° in valgus group). Although the pFeAV also increased (r = 0.145, P = .003), the tFeAV did not change significantly (P = .218). Mean tFeAV was 4.3° in varus, 4.7° in neutral, and 6.5° in valgus group. In contrast, as the coronal alignment changed from varus to valgus, the external tibial torsion increased (r = 0.374, P < .001; 22.6° in varus, 26.3° in neutral, and 32.6° in valgus group).

CONCLUSION

The change patterns of the rotational profiles of the lower extremity according to the coronal alignment should be considered in order to obtain satisfactory rotational alignment after TKA.

Mismatch between femur and tibia coronal alignment in the knee joint: classification of five lower limb types according to femoral and tibial mechanical alignment

Background

Reasons for dissatisfaction with total knee arthroplasty (TKA) include unequal flexion or extension gap, soft tissue imbalance, and patella maltracking, which often occur with mismatch between femoral and tibial coronal bony alignment in the knee joint or extremely varus or valgus alignment. However, lower limb coronal alignment classification is based only on hip–knee–ankle angle (HKAA), leading to oversight regarding a mismatch between femoral and tibial coronal alignment. We aimed to classify alignment of the lower limbs according to the mechanical alignment of the femur and tibia in a healthy population.

Methods

All 214 normal triple films were reviewed retrospectively. HKAA, mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), angle between the femoral anatomical axis and the mechanical axis (AA-MA), and knee alignment angle (KAA) were measured. Subjects were categorized into one of five types based on the mechanical alignment of femur and tibia.

Results

Mean HKAA, mLDFA, and mMPTA of all subjects were 1.2°, 87.3°, and 85.8°, respectively. All subjects were classified into one of five types with significant differences (p < 0.001). About 61% of subjects showed neutral alignment, of which nearly 40% were type 2 (valgus of the femur and varus of the tibia with oblique joint line: mLDFA 85.0° ± 1.4°, mMPTA 85.1° ± 1.2°, TJLA 2.7° ± 2.4°) and 60% exhibited neutral alignment with a neutral femur and tibia (type 1). In varus and valgus types, mismatch between the mechanical angle of the femur and tibia was common. Varus alignment, including types 3 (varus of the tibia: mLDFA 88.0° ± 1.4°, mMPTA 83.5° ± 1.6°) and 4 (varus of both the tibia and femur: mLDFA 91.4° ± 1.4°, mMTPA 85.2° ± 2.0°), was found in 30% of subjects. Valgus alignment (type 5 valgus of femur: mLDFA 84.6° ± 1.6°, mMPTA 88.8° ± 2.0°) accounted for 8.9% of all subjects.

Conclusions

Mismatch between mechanical alignment of the femur and tibia was common in varus and valgus alignment types. Joint line obliquity was also observed in 40% of the neutral alignment population. This classification provides a quick, simple interpretation of femoral and tibial coronal alignment, and more detailed guidance for preoperative planning for TKA than the traditional varus–neutral–valgus classification.

Electronic supplementary material

The online version of this article (10.1186/s12891-018-2335-9) contains supplementary material, which is available to authorized users.

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.

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.

Slight under-correction following total knee arthroplasty for a valgus knee results in similar clinical outcomes

BACKGROUND

Restoration of correct coronal alignment is one of the main goals of total knee arthroplasty (TKA). Traditionally, TKA has been considered successful when a neutral mechanical hip-knee-ankle (HKA) axis within 3° is achieved. Recent studies have reported no differences or improved clinical outcomes following a slight under-correction of the HKA axis for a varus knee. However, the influence of under-correction of a valgus knee has not been reported. This study investigated the influence of post-operative HKA alignment in TKA patients with valgus deformity on clinical outcomes.

METHODS

Ninety-three knees (93 patients) with pre-operative valgus alignment were evaluated with a mean follow-up period of 60 months. All patients were classified into three groups based on post-operative HKA alignment: neutral (0 ± 3°), mild valgus (3°-6°), and severe valgus (> 6°). These groups were compared using the Western Ontario and McMaster Universities osteoarthritis (WOMAC) index, the Knee Society (KS) knee score, KS function score, α-angle, β-angle, patella tilt angle, and the congruence angle.

RESULTS

Sixty-nine knees were included in the neutral group, seventeen knees in the mild valgus group, and seven knees in the severe valgus group. In all cases, post-operative clinical and functional scores significantly improved compared to pre-operative scores. There were no differences between the three groups in post-operative clinical and functional scores. More post-operative patellar tilt angle outliers (> 10°) and congruence angle outliers (> 16°) were apparent in the severe valgus group (patellar tilt angle, 13 vs. 17 vs. 57.1%, p = 0.022; congruence angle, 32 vs. 47 vs. 71%, p = 0.035).

CONCLUSIONS

Slight under-correction following TKA for a valgus knee resulted in similar clinical outcomes. A residual valgus angle of more than 6° can induce patellar maltracking.

LEVEL OF EVIDENCE

III, Retrospective comparative study.

Short-term and mid-term results of lateral condyle sliding osteotomy in the treatment of valgus total knee arthroplasty: A successful therapy option in Grade 2 valgus total knee arthroplasty

BACKGROUND

Different methods exist for deformity correction and ligament balancing in total knee arthroplasty (TKA) of valgus knees, the sliding osteotomy being one of them. The objective of the current study was to analyze the clinical and radiological short-term and mid-term results of this technique in a larger series.

METHODS

Between June 2007 and May 2014, 98 patients were treated with 98 TKAs and a simultaneous sliding osteotomy. All of them had a Grade 2 fixed valgus deformity (between 10° and 20°). All patients received a mobile-bearing, non-constrained (CR) implant. After prospective inclusion (T1), patients were clinically assessed after one (T2) and 4.5years (±2.1years) (T3), and radiological and Oxford Knee Score (OKS), Knee Society Knee Score (KSS) and the Knee Society Function Score (KSF) were obtained.

RESULTS

All knees were corrected to a mechanical leg alignment within three degrees. Significant improvement of all scores could be measured at T2 and T3. Seven revisions needed to be performed; three of them were procedure-related. In two of them, a problem of capsular closure occurred, while in one the slided epicondyle dislocated after three months. All other revisions were performed because of non-procedure-related problems (e.g. infection).

CONCLUSIONS

Sliding osteotomy of the lateral condyle is a successful option for the treatment of Grade 2 fixed valgus deformity. Due to this technique, higher constraint could be avoided. The results stayed constant over time. The procedure-related complications need to be kept in mind. Long-term results still need to be awaited.

Factors affecting femoral rotational angle based on the posterior condylar axis in gap-based navigation-assisted total knee arthroplasty for valgus knee

Background

Achieving proper rotational alignment of the femoral component in total knee arthroplasty (TKA) for valgus knee is challenging because of lateral condylar hypoplasia and lateral cartilage erosion. Gap-based navigation-assisted TKA enables surgeons to determine the angle of femoral component rotation (FCR) based on the posterior condylar axis. This study evaluated the possible factors that affect the rotational alignment of the femoral component based on the posterior condylar axis.

Materials and methods

Between 2008 and 2016, 28 knees were enrolled. The dependent variable for this study was FCR based on the posterior condylar axis, which was obtained from the navigation system archives. Multiple regression analysis was conducted to identify factors that might predict FCR, including body mass index (BMI), Kellgren-Lawrence grade (K-L grade), lateral distal femoral angles obtained from the navigation system and radiographs (NaviLDFA, XrayLDFA), hip-knee-ankle (HKA) axis, lateral gap under varus stress (LGVS), medial gap under valgus stress (MGVS), and side-to-side difference (STSD, MGVS − LGVS).

Results

The mean FCR was 6.1° ± 2.0°. Of all the potentially predictive factors evaluated in this study, only NaviLDFA (β = −0.668) and XrayLDFA (β = −0.714) predicted significantly FCR.

Conclusions

The LDFAs, as determined using radiographs and the navigation system, were both predictive of the rotational alignment of the femoral component based on the posterior condylar axis in gap-based TKA for valgus knee. A 1° increment with NaviLDFA led to a 0.668° decrement in FCR, and a 1° increment with XrayLDFA led to a 0.714° decrement. This suggests that symmetrical lateral condylar hypoplasia of the posterior and distal side occurs in lateral compartment end-stage osteoarthritis with valgus deformity.

Effect of individual distal femoral valgus resection in total knee arthroplasty for patients with valgus knee: A retrospective cohort study

BACKGROUND

Proper limb alignment and implant positioning are important for successful total knee arthroplasty (TKA). It remains unknown whether any differences exist in the restoration of limb alignment for valgus knees between fixed and individual femoral valgus correction angle (VCA) for distal femoral resection.

METHODS

A total of 63 patients (66 knees) had fixed 4° VCA (fixed group), and 55 patients (59 knees) had individual VCA (individual group). We compared the VCA, mechanical femorotibial (MFT) angle, femoral component angle (α), and tibial component angle (β) between the two groups.

RESULTS

There were statistically significant differences in postoperative MFT angle between the two groups (2.0° ± 1.2° versus 2.8° ± 1.6°, p < 0.002). A total of 51 (77.3%) patients in the individual group had postoperative alignment deviation within ±3° compared with that of 32 (54.2%) patients in the fixed group (p = 0.006). We found better postoperative alignment accuracies in the individual group for grade II knee valgus deformities (1.8° ± 1.2° versus 2.8° ± 1.5°, p = 0.00). There was a significant difference in α angle deviations between the two groups (1.7° ± 1.3° versus 2.5° ± 1.8°, p = 0.00). The number of patients with postoperative femoral coronal component alignment deviations within ±3° in the individual group was higher compared to that in the control group (87.8% versus 67.8%, p = 0.006).

CONCLUSIONS

This radiological study showed that individual VCA for distal femoral resection could achieve better postoperative alignment accuracy and fewer outliers of limb and femoral component malalignment in the coronal plane.

How to accurately determine the distal femoral valgus cut angle in the valgus knee arthroplasty

PURPOSE

Distal femoral resection in total knee arthroplasty (TKA) is commonly performed using intramedullary jigs with a pre-operatively planned valgus cut angle (VCA). For valgus knees with lateral femoral condyle hypoplasia, the method of determining the accurate VCA has not been clarified. The aim of the present study is to introduce a method that can accurately determine the distal femoral VCA in the valgus knee arthroplasty.

METHODS

Twenty patients with valgus deformity caused by lateral femoral condylar hypoplasia underwent primary TKA with individually measured VCA. The VCA was defined as the acute crossing angle of the anatomical and mechanical axes of the femur on a pre-operative X-ray film, and the two axes almost always crossed at the distal femoral diaphysis, but not the centre of the knee as generally described. The entry point of the femoral intramedullary guide rod was determined on the extension of the femoral anatomical axis and was usually medial to the centre of the knee. According to the pre- and post-operative X-ray films, the mechanical lateral distal femoral angle (mLDFA), and coronal alignment of the femoral components were measured. The post-operative knee pain and function were evaluated using the Visual Analog Scale and Knee Society Score, respectively.

RESULTS

The mean VCA measured according to the above method was 6.4° ± 1.0° (4.7-8.2°), and the femoral entry point was located at a mean distance of 7.4 ± 2.1 mm (4.5-10.9 mm) medial to the centre of the knee joint. The mean mLDFA before and after operation was 77.4° ± 5.7° (74-82°) and 88.4° ± 1.7° (86-90°), respectively, showing a statistically significant difference (P < 0.01).

CONCLUSIONS

The deformity of the distal femoral diaphysis is quite various in different valgus knees. The VCA and the femoral entry point should be determined individually for each case. The application of the current method resulted in good post-operative mechanical axis alignment and clinical results after TKA.

LEVEL OF EVIDENCE

Level IV.

An anatomic study of trifurcate iliotibial bands for correcting valgus knee deformity

BACKGROUND

The iliotibial band (ITB) trifurcates into the anterior, central and posterior branches at the knee level, and sometimes the branches must be selectively released to correct the valgus knee deformity during total knee arthroplasty. However, the anatomical morphology of the trifurcate ITBs has not been investigated.

METHODS

Fifty-two knees from 26 embalmed cadavers were dissected to observe and record the relationship of the three branches given off from the ITB trifurcation. Fourteen parameters with regard to the length, width, thickness, and trifurcate angle of each branch were measured. These parameters were compared between sex and sides (left or right). Meanwhile, the correlations between parameters and subject age, weight and height were assessed.

RESULTS

The longest, widest and thickest branches of the ITB were the posterior band (59.82±5.14mm), anterior band (39.56±4.17mm) and central band (2.61±0.36mm), respectively. The length and thickness of ITB were significantly larger in males than in females (P<0.05). No significant differences were found between sides (P>0.05). The ITB thickness showed a negative correlation with subject age, while the length and width of the ITB were positively correlated with subject height and weight, respectively.

CONCLUSIONS

This study provided an anatomical reference of trifurcate ITBs to help the release of ITB in valgus knees. The anatomical variations regarding the subject's sex, age, height and weight should be considered in the selective release of ITB.

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.

Total Knee Arthroplasty in Severe Valgus Osteoarthritis Excellent Early Results in a 90-Year-Old Patient with a Valgus Deformity of 47°

Grade III valgus deformity (tibiofemoral alignment > 20°) is present in only 0.5% of patients receiving total knee arthroplasty. Furthermore, cases with a valgus deformity exceeding 40° are even rarer. Since they mostly affect elderly, polymorbid patients, successful outcome means a great challenge. We report on a case of a 90-year-old patient with a valgus deformity of 47°. The patient was preoperatively restricted to a wheel chair, unable to walk, and only able to stand for a few seconds. The maximal knee flexion was 100°, and there was an extension deficit of 15°. The WOMAC score was 91; the EQ-5D-5L Index was 0.048. She was treated with a constrained hinged prosthesis. Postoperatively, the axis was 6° valgus. After 3 months of rehabilitation, she was independent using a wheeled walker. The maximal flexion of the knee was 110° and there was no extension deficit. The WOMAC score was 45; the EQ-5D-5L Index was 0.813. This case demonstrates the possibility of a satisfactory result and an improvement in quality of life and mobility with a plausible timetable and with reasonable use of resources even in advanced age and severe valgus deformity.

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.

Clinical Outcomes of Patients with Valgus Deformity Undergoing Minimally Invasive Total Knee Arthroplasty Through the Medial Approach

Objective:

The purpose of this study was to compare the clinical outcomes between patients with a valgus or varus deformity undergoing minimally invasive total knee arthroplasty through the medial approach.

Methods:

The patients were classified into 2 groups according to the preoperative femorotibial angle measured on an anteroposterior long leg roentgenogram. The valgus group comprised of 26 knees in 21 patients with a femorotibial angle <170° (163.5 ± 5.7), and the varus group comprised of 24 knees in 21 patients with a femorotibial angle >190° (195.9 ± 5.5). The following background variables were compared between the groups: age at the time of the operation, sex, causative disease, preoperative femoral mechanical–anatomical angle, and postoperative knee range of motion, Knee Society score, femorotibial angle, and implant position.

Results:

There were significant differences between the valgus and varus groups in the age (68.0 ± 6.9 vs 75.8 ± 6.2 years), percentage of males (23.8% vs 0%), percentage with rheumatoid arthritis (61.9% vs 4.8%), and preoperative femoral mechanical–anatomical angle (6.2 ± 1.0° vs 7.4 ± 2.1°). Clinical outcome variables of postoperative femorotibial angle (173.1 ± 3.9° vs 175.2 ± 1.6°) and α angle (96.6 ± 3.1° vs 95.0 ± 1.9°) also differed.

Conclusion:

It was assumed that over-valgus resection of the femur is a contributory factor to residual valgus alignment. However, knee range of motion and Knee Society score did not differ between the groups. We suggest that minimally invasive total knee arthroplasty through the medial approach is one of the treatment options for patients with valgus deformity.

Patients with isolated lateral osteoarthritis: Unicompartmental or total knee arthroplasty?

BACKGROUND

Lateral unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) are both reliable treatment options for patients with isolated lateral osteoarthritis (OA). However, studies comparing both procedures are scarce. Aims of this study were to (I) compare short-term functional outcomes following lateral UKA and TKA and (II) assess the role of patient characteristics on outcomes as measured by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC).

METHODS

In this retrospective cohort study, 82 patients (48 undergoing lateral UKA and 34 undergoing TKA) were identified that presented with lateral OA and completed the WOMAC. Independent t-tests were used to compare outcomes following lateral UKA and TKA.

RESULTS

Mean follow-up was 2.8 years (range: 2.0 - 5.0 years). Preoperatively, no differences between lateral UKA and TKA were seen (50.1±13.5 and 53.3±17.1, respectively, p=0.551). Postoperatively, lateral UKA patients reported better overall outcomes than TKA (90.5±11.7 vs. 81.8±17.9, p=0.017). Subgroup analysis showed better outcomes following lateral UKA than TKA in patients younger than 75 years (92.1±9.9 vs. 81.3±19.6, p=0.014) and in females (91.6±9.9 vs. 81.0±18.2, p=0.014).

CONCLUSION

These findings indicate that lateral UKA has superior short-term functional outcomes compared to TKA in patients with isolated lateral OA. Better outcomes were especially seen in younger patients and females. These findings may help orthopedic surgeons choose treatment for patients presenting with lateral OA and optimize treatment for individual patients.

New insight in the architecture of the quadriceps tendon

BACKGROUND

Published data regarding the structure of the quadriceps tendon are diverse. Dissection of the quadriceps muscle group revealed that beside the rectus femoris, vastus lateralis, vastus intermedius and vastus medialis a fifth muscle component- named the tensor vastus intermedius consistently fused into quadriceps tendon. It can be hypothesized that all these elements of the extensor apparatus of the knee joint must also be represented in the quadriceps tendon. This study investigated the multi-layered quadriceps tendon with special emphasis on all components of the quadriceps muscle group including the newly discovered tensor vastus intermedius.

METHODS

Ten cadaveric lower limbs were dissected. All muscle bellies of the extensor apparatus of the knee joint were identified and traced distally until they merged into the quadriceps tendon. Connections between the different aponeurotic layers of each muscle were studied from origin to insertion. The fusing points of each layer were marked. Their distance to the patella and the distances between the fusing points were measured.

RESULTS

Six elements of the quadriceps muscle group form a tri-laminar structure of the quadriceps tendon. The intermediate layer could be further sub-divided. The elements of the quadriceps tendon are 1. lateral aponeurosis of the vastus intermedius, 2. deep and 3. superficial medial aponeurosis of the vastus intermedius, 4. vastus lateralis, 5. tensor vastus intermedius and 6. rectus femoris. Even with differences in fiber direction - these elements join each other a certain distance proximal to the patella. All elements were fused over a region measuring 13 to 90 mm proximal to the patella. Lateral parts of the vastus intermedius formed the deepest layer of the quadriceps tendon. The superficial and deep layer of the medial vastus intermedius aponeurosis fused 56 mm (range, 30 to 90 mm) and 33 mm (range, 13 to 53 mm) above the patella with the aponeurosis of the tensor vastus intermedius and vastus lateralis respectively. Together they built the two-layered intermediate layer of the quadriceps tendon. The tendon of the rectus femoris forms the superficial layer. The vastus medialis inserts medially in all layers of the quadriceps tendon. Fibers of the lateral muscle components were oriented towards the medial, and fibers of the medial muscle components were oriented towards the lateral femoral condyle.

CONCLUSIONS

The three-layered quadriceps tendon is formed by six elements. These are 1. lateral aponeurosis of the vastus intermedius, 2. deep and 3. superficial medial aponeurosis of the vastus intermedius, 4. vastus lateralis, 5. tensor vastus intermedius and 6. rectus femoris. These elements of the extensor apparatus join each other proximal to the patella in a complex onion-like architecture. Its two-layered intermediate layer shows variable fusions points. The vastus medialis contributes to the quadriceps tendon with its medial insertion into all layers of the quadriceps tendon.

A New Classification for the Varus Knee

BACKGROUND

A new classification for osteoarthritis of the knee associated with varus deformity is presented. This classification is derived from the combination of conventional radiographs, stress radiographs (when needed), and clinical examination.

METHODS

This study included the analysis of coronal alignment on full-leg standing radiographs of 526 patients awaiting knee arthroplasty for varus deformity in a single institution. Various mechanical and anatomic angles were measured, and these findings were combined with a basic clinical examination of patients. The radiographs were measured on 2 separate occasions to determine the intraobserver reliability. Cross-sectional studies such as computed tomography or magnetic resonance imaging were used to further refine observations about different wear patterns.

RESULTS

Varus deformity can either be intra-articular or extra-articular. Intra-articular deformities can be correctable or fixed. In fixed deformities, the status of the lateral ligament is taken into account. Extra-articular deformity can be metaphyseal or diaphyseal, and the possibility for intra-articular correction will depend on the degree of deformity and its distance from the joint.

CONCLUSION

This new classification allows for better definition of varus deformity, which can help surgeons during preoperative planning, particularly with their choice of implant and potentially the degree of constraint. The classification can also be a tool for further prospective studies about varus deformity.

Prospective comparative study of two methods for fixation after distal femur corrective osteotomy for valgus deformity; retrograde intramedullary nailing versus less invasive stabilization system plating

INTRODUCTION

The aim of this study was to compare the radiological and functional results of two different methods of fixation for the correction of femoral valgus deformities.

METHODS

Patients who had undergone osteotomy and correction of a valgus deformity from 2007 to 2013 were prospectively followed. Thirty three patients (20 females, 13 males) with 39 lower limbs were included in the study. Seventeen lower limbs were treated with retrograde intramedullary nailing (IMN) and 22 with less invasive stabilization system plating. Standing orthoroentgenograms of the lower limbs were taken pre-operatively and at the final follow-up. mLDFA, aLDFA, mechanical axis deviation (MAD) were measured in this orthoroentgenograms. Knee osteoarthritis outcome score (KOOS) and knee range of motion were used pre-operatively and at the final follow-up as part of the evaluation of the clinical results. All patients duration of surgery, length of hospital stay were assessed. Operations were performed by two orthopedic surgeons. The choice of correction method for each patient was determined by the surgeon. Pre-operative and post-operative values were simultaneously measured by two additional orthopedic surgeons.

RESULTS

The mean age of the patients was 26.2 years (18.0-51.0) in the plating group and 29.3 years (18.0-55.0) in the nailing group. Patients in the plating and nailing groups were followed up for 24.0 (12.0-60.0) and 27.8 (12.0-60.0) months. All patients were followed for a minimum of 12 months. No significant differences were observed between the groups in terms of age, sex, or duration of follow-up (p > 0.05) Comparison of the pre- and post-operative mLDFA, aLDFA, MAD, length of hospital stay, and duration of surgery between the plating group and nailing group, no significant difference was observed between the groups (p > 0.05). However, patients treated with retrograde IMN had significantly better post-operative results in terms of the KOOS and range of motion of the knee according to plating group (p < 0.05).

CONCLUSION

Retrograde IMN does not provide a radiological advantage over the LISS plating technique for valgus deformity but retrograde IMN and correction offered better functional results in cases of femoral valgus deformity than did the LISS plating method.

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.