Distal femoral osteotomy for valgus arthritic knees

Surgical Technique and Preliminary Outcomes of Double-Level Osteotomy for Valgus Deformity

Background

Data are limited regarding the surgical technique or outcomes of double-level osteotomy (DLO) combining medial closing-wedge distal femoral osteotomy and medial closing-wedge high tibial osteotomy in patients with moderate-to-severe valgus deformity.

Purpose/Hypothesis

To describe the surgical technique and assess the short-term outcomes and surgical accuracy of DLO in patients with a moderate or severe valgus deformity. It was hypothesized that this technique would result in good clinical outcomes with precise deformity correction.

Study Design

Case series; Level of evidence, 4.

Methods

Eight patients (mean age, 44.2 ± 10.9 years) with a moderate or severe valgus knee treated with DLO (9 knees; mechanical tibiofemoral angle [mTFA], 10.3°± 3.5°) were included. The mean follow-up was 25.1 ± 11.1 months. Preoperative to postoperative changes in radiographic parameters (mTFA, mechanical lateral distal femoral angle, mechanical medial proximal tibial angle, joint line convergence angle) and clinical scores (Hospital for Special Surgery score, Oxford Knee Score, Lysholm score) were assessed. Surgical accuracy was calculated by subtracting the achieved postoperative correction from the preoperatively planned targeted correction.

Results

The mTFA changed significantly from 10.3°± 3.5° preoperatively to -1.8°± 3.4° postoperatively (P < .001); the mechanical lateral distal femoral angle and mechanical medial proximal tibial angle changed significantly by 5.1°± 2.7° and 5.9°± 2.2°, respectively (P < .001 for both); and the posterior distal femoral angle decreased significantly from 85.9°± 3.1° to 84.2°± 2.4° (P < .01). There was no significant difference between pre- and postoperative joint line convergence angles (3.3°± 2.3° to 2.6°± 2.1°). The accuracy of the correction was high: the mTFA achieved postoperatively differed from the mTFA planned preoperatively by a mean of 2.7°± 1.9° (range, 0.6°-6.6°). Significant pre- to postoperative improvement was seen for all outcome scores (Hospital for Special Surgery, from 67 ± 11 to 93 ± 4; Oxford Knee Score, from 29 ± 7 to 43 ± 3; Lysholm, from 41 ± 24 to 89 ± 8; P < .001 for all).

Conclusion

High surgical accuracy was achieved, and patients who underwent varus DLO for valgus knees showed improved knee function at short-term follow-up. Varus DLO can be a surgical option to restore the optimal alignment and joint line obliquity in patients with moderate or severe valgus malalignment.

Additional Plate Fixation of Hinge Fractures After Varisation Distal Femoral Osteotomies Provides Favorable Torsional Stability: A Biomechanical Study

BACKGROUND

Hinge fractures are considered risk factors for delayed or nonunion of the osteotomy gap in distal femoral osteotomies (DFOs). Limited evidence exists regarding the treatment of hinge fractures after DFO, which could improve stability and thus bone healing.

PURPOSE

To (1) examine the effect of hinge fractures on the biomechanical properties of the bone-implant construct, (2) evaluate the biomechanical advantages of an additional fixation of a hinge fracture, and (3) test the biomechanical properties of different types of varisation DFOs.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 32 fresh-frozen human distal femora equally underwent medial closing wedge DFO or lateral opening wedge DFO using a unilateral locking compression plate. The following conditions were serially tested: (1) preserved hinge; (2) hinge fracture along the osteotomy plane; (3) screw fixation of the hinge fracture; and (4) locking T-plate fixation of the hinge fracture. Using a servo-hydraulic materials testing machine, we subjected each construct to 15 cycles of axial compression (400 N; 20 N/s) and internal and external rotational loads (10 N·m; 0.5 N·m/s) to evaluate the stiffness. The axial and torsional hinge displacement was recorded using a 3-dimensional optical measuring system. Repeated-measures 1-way analysis of variance and post hoc Bonferroni correction were used for multiple comparisons. Statistical significance was set at P < .05.

RESULTS

Independent from the type of osteotomy, a fractured hinge significantly (P < .001) increased rotational displacement and reduced stiffness of the bone-implant construct, resulting in ≥1.92 mm increased displacement and ≥70% reduced stiffness in each rotational direction, while the axial stiffness remained unchanged. For both procedures, neither a screw nor a plate could restore intact rotational stiffness (P < .01), while only the plate was able to restore intact rotational displacement. However, the plate always performed better compared with the screw, with significantly higher and lower values for stiffness (+38% to +53%; P < .05) and displacement (-55% to -72%; P < .01), respectively, in ≥1 rotational direction. At the same time, the type of osteotomy did not significantly affect axial and torsional stability.

CONCLUSION

Hinge fractures after medial closing wedge DFO and lateral opening wedge DFO caused decreased bone-implant construct rotational stiffness and increased fracture-site displacement. In contrast, the axial stiffness remained unchanged in the cadaveric model.

CLINICAL RELEVANCE

When considering an osteosynthesis of a hinge fracture in a DFO, an additional plate fixation was the construct with the highest stiffness and least displacement, which could restore intact hinge rotational displacement.

Effects of Lateral Opening-Wedge Distal Femoral Osteotomy on Meniscal Allograft Transplantation: A Biomechanical Evaluation

Background

Lateral meniscal deficiency with valgus malalignment increases the rate of lateral compartment osteoarthritis. Lateral meniscal allograft transplantation (LMAT) with a concomitant varus-producing opening-wedge distal femoral osteotomy (DFO) is an option yet to be evaluated biomechanically.

Purpose/Hypothesis

The purpose of this study was to clarify the biomechanical effects of the realignment procedure in the setting of LMAT. We hypothesized that (1) given the dependence of the lateral compartment on the lateral meniscus, a DFO and increasing degrees of varus would be insufficient to restore lateral compartment pressures to normal from a lateral meniscus-deficient state, and that (2) LMAT would restore lateral compartment pressures to the intact state while DFO would decrease lateral compartment pressures for any given state of the meniscus.

Study Design

Controlled laboratory study.

Methods

Ten cadaveric knees underwent opening-wedge varus-producing DFO secured by an external fixator. Anatomic alignment was standardized to 6° of mechanical valgus, and each joint was tested in full extension. Submeniscal placement of thin film pressure sensors allowed for the recording of contact pressure, peak contact pressure, and contact area. The specimens were loaded on a biaxial dynamic testing machine with loading angles between 9° valgus and 6° varus of mechanical alignment. Conditions tested included intact meniscus, meniscal deficiency, and meniscal transplantation.

Results

Isolated varus-producing DFO to 6° in the meniscus-deficient state failed to restore joint pressures and contact areas to the intact state, with significant changes in mean contact pressure (175%), mean peak contact pressure (135%), and contact area (-41%) (all P < .05 vs intact), while LMAT restored all outcome measures (all P > .05 compared with intact). After LMAT, every additional 1° of DFO correction contributed to a decrease in the mean contact pressure, peak pressure, and contact area of 5.6% (-0.0479 N/mm²), 5.9% (-0.154 N/mm²), and 1.4% (-6.99 mm²) for the lateral compartment and 7.3% (+0.034 N/mm²), 12.6% (+0.160 N/mm²), and 4.3% (+20.53 mm²) for the medial compartment, respectively.

Conclusion

Isolated DFO was inadequate to restore load distribution in meniscus-deficient knees, while concomitant LMAT restored near normal forces and improved the lateral compartment biomechanical profile.

Clinical Relevance

Our findings support the concomitant use of LMAT and varus-producing DFO in the setting of lateral meniscal deficiency with valgus malalignment. This study provides tools for the orthopaedic surgeon to individualize the correction for each patient.

Outcomes of Distal Femoral Osteotomy for Valgus Malalignment: A Systematic Review and Meta-analysis of Closing Wedge Versus Opening Wedge Techniques

BACKGROUND

Valgus knee deformity increases the risk for lateral articular chondral damage, contributing to earlier onset and accelerated progression of osteoarthritis. Distal femoral osteotomy (DFO) unloads the lateral joint compartment and can be performed using closing wedge (CW) or opening wedge (OW) techniques.

PURPOSE

To perform a systematic review and meta-analysis for patients with valgus knee deformity undergoing DFO to determine differences in patient-reported outcome measures (PROMs), complications, and survival rates, comparing CW versus OW DFO.

STUDY DESIGN

Systematic review, Level of evidence, 4.

METHODS

A literature review was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines utilizing PubMed, Cochrane Database, Ovid/MEDLINE, and Scopus. Inclusion criteria consisted of studies reporting outcomes in patients undergoing CW or OW DFO for the treatment of valgus knee deformities with symptomatic lateral compartment pathology with a minimum 2-year follow-up. PROMs and complications were analyzed using random-effects modeling to identify differences in outcomes as a function of surgical technique. Long-term survival data, defined as conversion to total knee arthroplasty, were analyzed using a multiple metaregression model as a function of individual study follow-up time points and surgical technique.

RESULTS

In total, we included 23 retrospective studies (n = 619 knees), of which 10 studies (n = 271 knees) reported outcomes after CW DFO and 13 studies (n = 348 knees) reported on OW DFO outcomes. Good to excellent clinical outcomes were reported in PROMs when compared with preoperative values with both techniques, while no significant differences between techniques were appreciated on functional Knee Society Scores and Tegner scores. No significant differences were appreciated in the incidence of complications reported in patients undergoing CW (20%) versus OW (33%) DFO (P = .432). Pain requiring hardware removal was the most commonly reported complication in both groups. The survival rate for CW DFO was 81.5% (mean follow-up, 8.8 ± 4.3 years) compared with 90.5% for OW DFO (mean follow-up, 4.5 ± 1.5 years). Multiple metaregression demonstrated that patient follow-up (P < .001) was significantly associated with knee survival, while surgical technique (P = .810) was not a predictor of clinical failure.

CONCLUSIONS

Both CW and OW DFO techniques were associated with good to excellent clinical outcomes with no significant differences in PROMs based on technique. Pain requiring hardware removal was the most common complication in both techniques, while long-term survivability was found to be a function of follow-up and not surgical technique. Technique selection should be based on shared patient-physician decision making with an emphasis on surgeon preference and technique familiarity.

Effect of Medial Closing Wedge Distal Femoral Varization Osteotomy on Coronal Ankle and Hindfoot Alignment

BACKGROUND

To date, only a few studies have reported postoperative changes in coronal ankle alignment after valgus knee correction through medial closing wedge distal femoral varization osteotomy (MCWDFO). This study aimed to measure the changes of MCWDFO on coronal ankle and hindfoot alignment.

METHODS

We retrospectively reviewed the radiographic findings of 27 consecutive patients (34 cases) with knee valgus malalignment who underwent MCWDFO for either lateral knee joint osteoarthritis (OA) or recurrent patellar subluxation/dislocation (RPD). Several radiographic parameters were measured and compared based on the reason for operation, followed by the status of preoperative hindfoot alignment (hindfoot alignment angle [HAA] > 4 degrees, varus; -4 degrees ≤HAA ≤ 4 degrees, neutral; HAA < -4 degrees, valgus) in each group.

RESULTS

Overall, pre- and postoperative hindfoot alignments were within the neutral alignment range and were not significantly changed after the operation (P > .05). Nineteen cases were for lateral knee OA and 15 were for RPD, respectively. In both groups, preoperative neutral hindfoot alignments accounted for the largest portion (52.6% in the lateral OA group; 80.0% in the RPD group). Postoperatively, regardless of the reason for operation, hindfoot alignments changed toward the neutral range in all subgroups (ie, no changes in the preoperative neutral group; increased in the valgus group; decreased in the varus group).

CONCLUSION

We recommend that surgeons leave the hindfoot untouched when they plan the MCWDFO to correct knee joint valgus malalignment concomitant with hindfoot valgus or varus deviation as the hindfoot malalignment appears to change toward the neutral range postoperatively.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Single-Stage Total Knee Arthroplasty and Open-Wedge Distal Femoral Osteotomy for Osteoarthritis with Femoral Shortening and Extra-Articular Varus Deformity: A Case Report

CASE

A 76-year-old female patient with a history of pyogenic arthritis of the right knee in childhood presented with severe osteoarthritis of the right knee with 24-mm femoral shortening and severe extra-articular femoral varus deformity. She received single-stage total knee arthroplasty (TKA) combined with a medial open-wedge distal femoral osteotomy and achieved good postoperative clinical and radiological results.

CONCLUSION

This case illustrated that extra-articular open-wedge distal femoral osteotomy and TKA performed simultaneously may be efficacious for severe extra-articular deformities with femoral shortening.

Distal femoral osteotomy versus lateral unicompartmental arthroplasty for isolated lateral tibiofemoral osteoarthritis with intra-articular and extra-articular deformity: a propensity score-matched analysis

Purpose

Lateral unicompartmental arthroplasty (UKA) and distal femoral osteotomy (DFO) represent surgical solutions in cases of valgus malalignment and isolated lateral osteoarthritis (OA) of the knee. The aim of the present study was to assess the clinical results, complications, and the overall postoperative alignment of a series of DFO and lateral UKA with a minimum 2-year follow-up in active middle-aged patients.

Methods

Patients with valgus knee and isolated lateral OA who underwent opening-wedge DFO or UKA from 2017 to 2019 were reviewed. Each patient was characterized by a joint line convergence angle (JLCA) > 3° and mechanical lateral distal femoral angle (mLDFA) < 87°. We excluded patients who underwent meniscus or osteochondral allograft during DFO. The Oxford Knee Score (OKS), Knee Injury and Osteoarthritis Outcome Score (KOOS), complications, and postoperative alignment were assessed. Propensity score matching was used to identify comparable patients.

Results

The DFO and lateral UKA groups consisted of 29 patients each. No statistically significant differences in gender, age, body mass index (BMI), length of follow-up, or limb deformity were reported between the two groups. In the DFO group, OKS was reported to improve from 27.51 to 38.59 (p < 0.05) and KOOS from 51.14 to 67.2 (p < 0.05). Similarly, in the UKA group, OKS improved from 26.23 to 35.43 (p < 0.05) and KOOS from 50.12 to 65.91 (p < 0.05). However, the improvement in OKS and KOOS (delta) did not differ between groups (p = 0.35 and p = 0.95). The DFO and UKA groups were characterized by similar postoperative hip-knee-ankle (HKA) angle measurements of −3.26 and −3.00, respectively (p = 0.65). No patients in the UKA group underwent revision or other knee surgeries during follow-up. No infections were detected in either group. In the DFO group, no cases of nonunion or delayed union were reported. However, 40% of DFO patients underwent plate removal. One patient in each group was characterized by progression of medial OA with Kellgren-Lawrence (KL) grade > 3.

Conclusion

UKA and DFO represent an effective treatment in lateral knee OA with intra-articular and extra-articular deformity. Both surgeries were able to provide a significant and comparable clinical improvement.

Level of evidence: III, comparative retrospective cohort study.

Osteotomies for lateral compartment knee osteoarthritis

Lateral compartment osteoarthritis (LCOA) is often associated with valgus deformity of the knee. The concept of correcting the alignment by performing distal femoral varus osteotomy (DFVO) to unload the lateral compartment is well accepted and it is viewed as the preferred option for young active patients due to dissatisfaction from arthroplasty under 55 years of age or if they wish to remain active. Beyond this there is no consensus on patient selection, preoperative assessment, techniques to achieve correction, end point of correction, return to work or sports post-surgery, and survivorship of osteotomy with conversion to a total knee replacement as the end point due to heterogenous, retrospective studies. Here, we review relevant literature to help patient selection, preoperative work up, techniques, and outcomes.

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

Purpose

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

Materials and methods

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

Results

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

Conclusions

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

Return to Work and Sport After Distal Femoral Osteotomy: A Systematic Review

CONTEXT

Distal femoral osteotomy (DFO) is a joint preservation procedure that corrects genu valgum deformities and patellofemoral maltracking, thereby restoring kinematics and unloading contact pressures in the lateral tibiofemoral and patellofemoral compartments.

OBJECTIVE

To evaluate the rates of return to work (RTW) and return to sport (RTS) after DFO for valgus malalignment and lateral compartment osteoarthritis through a systematic review of the literature.

DATA SOURCES

A systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted on the PubMed, Cochrane, and Embase databases.

STUDY SELECTION

The search terms femoral osteotomy AND (sports OR work) were used. Studies in which patients underwent concomitant total knee arthroplasty were excluded.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 4 (systematic review of level 4 studies).

DATA EXTRACTION

Data included the number of patients, age, gender, laterality of operation, time to follow-up, rate of RTW and RTS, time to RTS, activity level on return, and activity level scores (Tegner, Marx, Lysholm, and the International Knee Documentation Committee). Risk of bias was assessed using the Methodological Index for Non-Randomized Studies (MINORS) criteria.

RESULTS

Seven articles with 194 patients were included. The average age ranged from 19 to 49 years with a mean postoperative follow-up range of 36 to 90 months. RTW data were available for 125 patients, of whom 42.1% to 91.3% returned by final follow-up. Data on RTS were available for 149 patients, of whom 70% to 100% returned at a range of 8.3 to 16.9 months postoperatively, and 41.6% to 100% returned to the same or greater level of sports activity. The Tegner and Marx activity level scores ranged from 3 to 4 and from 5 to 11, respectively, at final follow-up.

CONCLUSION

Patients treated with DFO reported high rates of RTW and RTS, with most patients being able to return to recreational sport after surgery.

Ten-year survival rate of 89% after distal femoral osteotomy surgery for lateral compartment osteoarthritis of the knee

PURPOSE

The purpose of this study was to assess the accuracy, safety, and survival of distal femoral osteotomy (DFO) surgery for lateral compartment OA of the knee.

METHODS

A retrospective cohort study was conducted at a single UK centre, using prospectively collected data over an 8-year period (2009-2017). All patients had pre-operative radiographic analysis and digital planning of their deformity correction in addition to post-operative analysis of the achieved correction and yearly face-to-face follow-up. Complications (defined as an undesirable medical or surgical event as a direct result of the operation), reoperations, and failure (defined as conversion to arthroplasty or revision) were recorded.

RESULTS

From a total of 83 patients, 81 patients undergoing 86 primary DFOs were included in this study, with a mean follow-up of 99 months (SD 27 months). The mean pre-operative percentage Mikulicz point was 78.7% (SD 19.1%) and post-operative 35.9% (SD 14.8%). The mean accuracy of correction (intended correction - achieved correction) was an 8.2% overcorrection (SD 13.7%). The complication rate was 4.7%. Using Kaplan-Meier analysis, the mean survival was 113 months (95% CI 106-120) with the probability of surviving 10 years 89%.

CONCLUSION

DFO for valgus alignment and lateral compartment arthritis is associated with low complications, long-term joint preservation, and the prevention of arthroplasty surgery. However, the accuracy of correction still requires improvement in intra-operative technique.

LEVEL OF EVIDENCE

IV.

A hinge position distal to the adductor tubercle minimizes the risk of hinge fractures in lateral open wedge distal femoral osteotomy

PURPOSE

To evaluate the incidence and morphology of medial cortical hinge fractures in lateral open wedge distal femoral osteotomy (LOW-DFO) and to determine a safe zone for the position of the osteotomy hinge to minimize the risk of hinge fractures.

METHODS

Consecutive patients who underwent LOW-DFO for symptomatic valgus malalignment were screened for eligibility for this retrospective observational cohort study. Demographical and surgical data were collected. The incidence and morphology of medial cortical hinge fractures were evaluated on standard postoperative anterior-posterior knee radiographs. Comprehensive measurements evaluating the osteotomy gap and the position of the osteotomy hinge were taken. Additionally, each osteotomy hinge was assigned to a corresponding sector of a proposed five-sector grid of the distal medial femur.

RESULTS

A total of 100 patients (60% female) with a mean age of 31 ± 13 years were included. The overall incidence of medial cortical hinge fractures was 46% and three distinct fracture types were identified. The most frequently observed fracture type was extension of the osteotomy gap (76%), followed by a proximal (20%) and distal (4%) course of the fracture line in relation to the hinge. Group comparison (hinge fracture vs. no hinge fracture) showed statistically significant higher values for the height of the osteotomy gap (p = 0.001), the wedge angle (p = 0.036), and the vertical distance between the hinge and the proximal margin of the adductor tubercle (AT; p = 0.002) in the hinge fracture group. Furthermore, a significantly lower horizontal distance between the hinge and the medial cortical bone (p = 0.036) was observed in the hinge fracture group. A statistically significant higher incidence of medial cortical hinge fractures was observed when the position of the osteotomy hinge was proximal compared to distal to the proximal margin of the AT (53% vs. 27%; p = 0.023).

CONCLUSION

Medial cortical hinge fractures in LOW-DFO are a common finding with three distinct fracture types. To minimize the risk of medial cortical hinge fractures, it is recommended to aim for a position of the osteotomy hinge at the level of or distal to the proximal margin of the adductor tubercle.

LEVEL OF EVIDENCE

Prognostic study; Level III.

Resultados a longo prazo de osteotomia varizante femoral distal (OVFD) com cunha de abertura lateral para artrose do compartimento lateral do joelho utilizando navegação computadorizada

Objective  The primary aim of the present study was to evaluate the long-term outcomes including survivorship of computer navigated distal femoral lateral opening wedge osteotomy (DFLOWO). The secondary aim was to identify the potential factors that may influence its survivorship.

Methods  A retrospective analysis of prospectively collected data for patients with lateral compartment arthritis who underwent navigated DFLOWO from December 2006 to November 2012 was performed. The International Knee Documentation Committee (IKDC) and Knee Injury and Osteoarthritis Outcome Score (KOOS) scores were analyzed for outcome measures. Conversion to arthroplasty during the follow-up was the end point.

Results  A total of 19 DFLOWOs were performed in 17 patients with a mean age of 46.6 ± 6.5 years formed the study cohort. The coronal alignment was corrected from a mean of 7.1° (2–11°) valgus to a mean of 2.1° (0.5°–3°) varus. The IKDC scores improved from mean of 39 preoperatively to 53 at the mean long-term follow-up of 9.1 years. The mean KOOS scores at the long-term follow-up were pain 71, symptoms 56, activities of daily living 82, sports and recreation 59, quality of life 43. Survivorship of the DFLOWO was 78.9% at a follow-up of 9.1 years. Presence of ≥ grade 2 according to the International Cartilage Repair Society (ICRS) cartilage degeneration in the medial compartment of the knee and >7° preoperative valgus deformity were strongly correlated with conversion to total knee arthroplasty (TKA) at the long-term follow-up ( r  = 0.66).

Conclusions  Computer navigated DFLOWO has satisfactory clinical outcomes and 79% survivorship in long-term follow-up. Presence of more than ICRS ≥ grade 2 degenerative changes in the medial compartment of knee with > 7° preoperative valgus deformity negatively affects the survivorship of DFLOWO in the long-term follow-up.

Effects of lateral opening wedge and medial closing wedge distal femoral osteotomies on axial load stability

BACKGROUND

The stability of the current distal femoral osteotomy is insufficient for early weight bearing and bone healing. The purpose of this study was to test the stability of medial closing wedge- (MCW-) and lateral opening wedge-distal femoral osteotomies (LOW-DFO), which have improved with the recent advances in technology.

METHODS

We used composite bone models with MCW-DFO, improved with biplanar osteotomy technique and a Tomofix™ MDF plate, or LOW-DFO improved with biplanar osteotomy technique, a Tomofix™ LDF plate, and a β-TCP bone substitute, BONISH® graft. A cyclic axial loading test was employed to evaluate the strain on a plate and hinge point. The breaking axial load was measured.

RESULTS

Tensile strain on the plate produced by cyclic axial loading was significantly lower for LOW-DFO (2.0 ± 0.8 MPa) than for MCW-DFO (3.9 ± 1.6 MPa, P < .05). Compressive strain on the hinge point produced by cyclic axial loading was lower for LOW-DFO (6.6 ± 2.9 MPa) than for MCW-DFO (7.7 ± 4.6 MPa,). The maximum breaking axial load was significantly higher for LOW-DFO (5511 ± 945 N) than for MCW-DFO (4303 ± 518 N, P < .05).

CONCLUSIONS

LOW-DFO improved with recent advanced technology was superior to MCW-DFO improved with advanced technology in both cyclic axial loading test and breaking axial load test. This suggests that LOW-DFO facilitates earlier weight bearing and bone healing than does MCW-DFO.

Medial Open-wedge Osteotomy with Double-plate Fixation for Varus Malunion of the Distal Femur

Objective

To present our clinical experience of treating varus malunion of the distal femur through a medial open‐wedge osteotomy with double‐plate fixation.

Methods

A prospective cohort study was performed. From January 2005 to February 2015, 15 consecutive patients with varus malunion following distal femur fractures were surgically treated at a single level I trauma center. The coronal and sagittal deformity were corrected by a medial open‐wedge osteotomy of the distal femur. A medial buttress plate was used to maintain the realignment. A lateral locking plate was additionally used as a protection plate. The mean age of patients at the time of the surgery was 35.5 years (range, 22–58 years). The radiographical evaluation included the mechanical femorotibial angle, the mechanical lateral distal femoral angle, the anatomic posterior distal femoral angle, and the leg length discrepancy. Clinical outcome evaluation consisted of the range of motion (ROM) and Hospital for Special Surgery (HSS) score.

Results

Mean follow‐up was 7.4 years (range, 4–11.5 years). Varus and flexion malalignment and limb discrepancy were adequately corrected in all patients. The mechanical femorotibial angle, the mechanical lateral distal femoral angle, and the anatomic posterior distal femoral angle were restored from 17.5° (range, 13°–25°) to 2.3° (range, − 2°–7°), 102.3° (range, 95°–112°) to 85.2° (range, 81°–92°), and 77.1° (range, 65°–87°) to 82.7° (range, 76°–88°), respectively. The leg length discrepancy was diminished from 3.4 cm (range, 2.4–4.5 cm) to 0.8 cm (range, 0–1.7 cm). The average bone healing time was 4.1 months (range, 2.5–6 months). The average ROM of the affected knees at 24‐month follow‐up was 3.4°–112.55°. The score of HSS at 4‐years follow‐up was 76.1 (range, 64–88). No internal fixation failure or secondary operation was noted until the last follow‐up.

Conclusion

Medial open‐wedge osteotomy can adequately correct the posttraumatic varus malunion of the distal femur. With fixation of the double plate, non‐displaced bone healing and good functional outcome are expected.

Successful Return to Sport Following Distal Femoral Varus Osteotomy

OBJECTIVE

Distal femoral varus osteotomy (DFVO) is an effective treatment for unloading valgus knee malalignment; however, there is limited evidence on the ability for patients to return to athletics following this procedure. The purpose of this study is to report the functional outcomes and rate of return to sport for athletes that underwent DFVO.

DESIGN

A consecutive series of athletes that had undergone DFVO were retrospectively reviewed. Radiographs were assessed to determine preoperative and postoperative alignment. Institutional registries were used to collect preoperative and postoperative Marx Activity Scale, International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form scores, and return to sport.

RESULTS

Thirteen patients (8 males, 5 females) with a mean age of 24 years (range 17-35 years) and a mean follow-up of 43 months (range 24-74 months) were included in the study. Six patients underwent medial closing wedge DFVO versus 7 patients who underwent lateral opening wedge DFVO. Nine of 13 had concomitant chondral, meniscal, or ligamentous procedures performed. The mean alignment correction was 8° (range 5°-13°). All patients were able to successfully return to sport at a mean of 11 months (range 9-13 months). Furthermore, all 13 patients demonstrated an improvement in both Marx Activity Scale (4-11; P < 0.01) and IKDC scores (53-89; P < 0.01) after surgery.

CONCLUSIONS

Correction of valgus knee malalignment through DFVO-either medial closing wedge or lateral opening wedge-can reliably result in improvement in function and return to sport. Concomitant chondral, meniscal, and ligamentous pathology should be addressed.

Distal Femoral Varus Osteotomy for Valgus Arthritis of the Knees: Systematic Review of Open versus Closed Wedge Osteotomy

Purpose

The purpose of this review is to compare the clinical and radiological outcomes between open and closed wedge distal femoral varus osteotomy (DFO).

Methods

A literature search of online databases (MEDLINE, EMBASE, and Cochrane Library database) was made in addition to manual search of major orthopedic journals. Data were searched from the time period of January 1990 to October 2016. A modified Coleman Methodology Score system was used to assess the methodologic quality of the included studies. A total of 20 studies were included in the review. All studies were level IV evidence.

Results

Comparative analysis of open and closed wedge DFO did not demonstrate clinical and radiological differences. The survival rates were also similar. Five studies (56%) on open wedge DFO mentioned the need for either bone grafting or substitute for osteotomy gap filling and reported higher incidences of reoperation for plate removal than the closed wedge DFO studies.

Conclusions

The present systematic review showed similar performance between open and closed wedge DFO. Outcomes including survival rates were not statistically significantly different. However, additional bone grafting or substitutes were often needed to prevent delayed union or nonunion for open wedge techniques. Additional operations for plate removal were commonly required due to plate irritation in both techniques.

Open Wedge Distal Femoral Osteotomy: Accuracy of Correction and Patient Outcomes

BACKGROUND

There is a renewed interest in joint preservation surgery, and lateral opening wedge distal femoral osteotomy (DFO), a joint-preserving procedure, has been used to treat symptomatic genu valgum when the deformity originates in the distal femur.

QUESTIONS/PURPOSES

This study aimed to measure the accuracy of lateral opening wedge DFO in achieving deformity correction using radiographic parameters. In addition, the ability of lateral opening wedge DFO to improve patient outcomes as measured by Short Form Health Survey (SF-36) scores and American Academy of Orthopedic Surgeons (AAOS) lower limb module (LLM) scores leading to successful joint preservation was assessed.

METHODS

The clinical charts and radiographs of 28 consecutive patients that underwent 41 DFOs (15 unilateral and 13 staged bilateral) using a locking plate construct were retrospectively reviewed. The mean age of patients undergoing DFO was 44 years (range 22-72), and 22 of the patients were female. The mean follow-up was 26 months (range 12-57 months). Preoperative and postoperative radiographs were evaluated for mechanical axis deviation (MAD), lateral distal femoral angle (LDFA), and the patella congruence angle (PCA). These measurements were compared to determine the accuracy of deformity correction. Clinical outcomes were assessed with preoperative and postoperative SF-36 and AAOS LLM, as well as Oxford knee scores at follow-up.

RESULTS

The accuracy of deformity correction was 95%. The MAD significantly improved from 25.3 mm lateral to the midline to 8 mm medial to the midline (p < 0.01). The LDFA significantly improved from 83.4° to 91.7° (p < 0.01). The PCA significantly improved from 30.4° lateral to 5.7° lateral (p = 0.02). Mean SF-36 scores significantly improved from 37.5 to 50.2 (p = 0.01); mean LLM scores improved from 71.6 to 85.9 (p = 0.021), and the mean postoperative Oxford knee score was 35 ± 6.2 (range 23-46). No patients required total knee arthroplasty at the time of final follow-up.

CONCLUSION

Opening wedge lateral DFO is a reliable procedure for the treatment of valgus knee malalignment with or without arthritic changes in the lateral compartment. Deformity correction is accurate, and patient outcomes reveal significant improvement after surgery. Longer follow-up is required to access the survivorship of this procedure.

Distal Femoral Osteotomy for the Valgus Knee: Medial Closing Wedge Versus Lateral Opening Wedge: A Systematic Review

PURPOSE

(1) To determine the radiographic correction/healing rate, patient-reported outcomes, reoperation rate, and complication rate after distal femoral osteotomy (DFO) for the valgus knee with lateral compartment pathology. (2) To summarize the reported results of medial closing wedge and lateral opening wedge DFO.

METHODS

We conducted a systematic review of PubMed, MEDLINE, and CINAHL to identify studies reporting outcomes of DFOs for the valgus knee. Keywords included "distal femoral osteotomy," "chondral," "cartilage," "valgus," "joint restoration," "joint preservation," "arthritis," and "gonarthrosis." Two authors first reviewed the articles; our study exclusion criteria were then applied, and the articles were included on the basis relevance defined by the aforementioned criteria. The Methodological Index for Nonrandomized Studies scale judged the quality of the literature. Sixteen studies were relevant to the research questions out of 191 studies identified by the original search.

RESULTS

Sixteen studies were identified reporting on 372 osteotomies with mean follow-up of 45 to 180 months. All studies reported mean radiographic correction to a near neutral mechanical axis, with 3.2% nonunion and 3.8% delayed union rates. There was a 9% complication rate and a 34% reoperation rate, of which 15% were converted to arthroplasty. There were similar results reported for medial closing wedge and lateral opening wedge techniques, with a higher conversion to arthroplasty in the medial closing wedge that was confounded by longer mean follow-up in this group (mean follow-up 100 v 58 months).

CONCLUSIONS

DFOs for the valgus knee with lateral compartment disease provide improvements in patient-reported knee health-related quality of life at midterm follow-up but have high rates of reoperation. No evidence exists proving better results of either the lateral opening wedge or medial closing wedge techniques.

LEVEL OF EVIDENCE

Level IV, systematic review of Level IV studies.

Varus-Producing Lateral Distal Femoral Opening-Wedge Osteotomy

Valgus knee alignment in excess of physiological valgus leads to excessive loading of the lateral compartment, which can potentially increase the risk of osteoarthritis and can place the medial knee structures at risk of chronic attenuation. Varus-producing distal femoral osteotomies have been proposed for correction of valgus malalignment, to relieve tension on medial-sided structures, as well as to off-load the lateral compartment. Understanding that symptomatic valgus deformity of the knee represents a complex problem that is magnified in the setting of lateral compartment arthritis or medial ligamentous incompetence, we present our preferred technique for a varus-producing distal femoral osteotomy using plate osteosynthesis and cancellous bone allograft.

Opening- and Closing-Wedge Distal Femoral Osteotomy: A Systematic Review of Outcomes for Isolated Lateral Compartment Osteoarthritis

Background:

Lateral compartment osteoarthritis of the knee can be a challenging pathology in the younger, active population due to limited treatment options and high patient expectations. Distal femoral osteotomy (DFO) has been reported to be a potential treatment option.

Purpose:

To perform a systematic review on the survival, outcomes, and complications of DFO for treatment of genu valgum with concomitant lateral compartment osteoarthritis of the knee.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A systematic review of the literature was performed using the Cochrane Database of Systematic Reviews, the Cochrane Central Registry of Controlled Trials, PubMed, and MEDLINE from 1980 to present. Inclusion criteria were as follows: outcomes of opening- and closing-wedge DFOs performed for treatment of genu valgum with concomitant lateral compartment osteoarthritis of the knee, English language, minimum 2-year follow-up, and human studies. Data abstracted from the selected studies included type of osteotomy (opening vs closing), survival rate, patient-reported and radiographic outcomes, and complications.

Results:

Fourteen studies met the inclusion criteria and were considered for the review. A total of 9 closing-wedge and 5 opening-wedge DFO studies were included. All were retrospective studies and reported good to excellent patient-reported outcomes after DFO. Survival decreased with increasing time from surgery, with 1 study reporting a 100% survival rate at 6.5 years, compared with 21.5% at 20 years in another study. A low rate of complications was reported throughout the review.

Conclusion:

Highly heterogeneous literature exists for both opening- and closing-wedge DFOs for the treatment of isolated lateral compartment osteoarthritis with valgus malalignment. A mean survival rate of 80% at 10-year follow-up was reported, supporting that this procedure can be a viable treatment option to delay or reduce the need for joint arthroplasty. A low complication rate was observed, with symptomatic hardware being the most prevalent postoperative complication.

Good functional results of distal femoral opening-wedge osteotomy of knees with lateral osteoarthritis

PURPOSE

To evaluate the time-dependent functional outcome of patients with lateral knee osteoarthritis with increased valgus treated with lateral opening-wedge osteotomy to shift the load from the lateral to the medial compartment of the knee.

METHODS

Twenty-four consecutive patients with lateral knee osteoarthritis were treated with distal femoral opening-wedge varus osteotomy stabilized with the Puddu plate and bone transplantation. The mean age of the patients was 48 years (CI 40.3-55.7, range 31-62). The patients were evaluated by the Knee Injury and Osteoarthritis Outcome Score (KOOS) preoperatively and at 3 and 6 months, 1, 2, 5 and 10 years post-operatively. The knee osteoarthritis was graded according to the Kellgren-Lawrence radiological scoring system. The mean follow-up time was 7.9 years (CI 6.8-9.0, range 4.0-10.2).

RESULTS

The mean angular correction measured on pre- and post-operative radiographs was 9.6° (CI 7.7°-11.5°, range 4°-20°). All osteotomies healed. KOOS increased significantly during the first year by 28-122 % beyond the preoperative values for all the five subscores. This improvement remained at 10-year follow-up for those with surviving osteotomy. Six knees were converted to total knee arthroplasty (TKA) mean 6.4 years (CI 3.3-9.6, range 4.0-11.8) post-operatively. The osteotomy survival rate at 5 years was 88 % and at 10 years 74 %. The preoperative osteoarthritic grade did not increase significantly during the follow-up period, but was significantly correlated (r = -0.49), P = 0.019 to the KOOS subscore symptoms at the 2-year follow-up.

CONCLUSION

Distal femoral opening-wedge osteotomy for lateral knee osteoarthritis resulted in good functional recovery after 1 year and favourable midterm results. It may be a good treatment option for middle-aged patients with valgus knees and lateral osteoarthritis in order to prevent or postpone TKA.

LEVEL OF EVIDENCE

IV.

Medial Closing-Wedge Distal Femoral Osteotomy: Fixation With Proximal Tibial Locking Plate

Distal femoral varus osteotomy is a well-established procedure for the treatment of lateral compartment cartilage lesions and degenerative disease, correcting limb alignment and decreasing the progression of the pathology. Surgical techniques can be performed with a lateral opening-wedge or medial closing-wedge correction of the deformity. Fixation methods for lateral opening-wedge osteotomies are widely available, and there are various types of implants that can be used for fixation. However, there are currently only a few options of implants for fixation of a medial closing-wedge osteotomy on the market. This report describes a medial, supracondylar, V-shaped, closing-wedge distal femoral osteotomy using a locked anterolateral proximal tibial locking plate that fits anatomically to the medial side of the distal femur. This is a great option as a stable implant for a medial closing-wedge distal femoral osteotomy.

The Meniscus-Deficient Knee: Biomechanics, Evaluation, and Treatment Options

Meniscal tears are the most common knee injury, and partial meniscectomies are the most common orthopaedic surgical procedure. The injured meniscus has an impaired ability to distribute load and resist tibial translation. Partial or complete loss of the meniscus promotes early development of chondromalacia and osteoarthritis. The primary goal of treatment for meniscus-deficient knees is to provide symptomatic relief, ideally to delay advanced joint space narrowing, and ultimately, joint replacement. Surgical treatments, including meniscal allograft transplantation (MAT), high tibial osteotomy (HTO), and distal femoral osteotomy (DFO), are options that attempt to decrease the loads on the articular cartilage of the meniscus-deficient compartment by replacing meniscal tissue or altering joint alignment. Clinical and biomechanical studies have reported promising outcomes for MAT, HTO, and DFO in the postmeniscectomized knee. These procedures can be performed alone or in conjunction with ligament reconstruction or chondral procedures (reparative, restorative, or reconstructive) to optimize stability and longevity of the knee. Complications can include fracture, nonunion, patella baja, compartment syndrome, infection, and deep venous thrombosis. MAT, HTO, and DFO are effective options for young patients suffering from pain and functional limitations secondary to meniscal deficiency.

Varization open-wedge osteotomy of the distal femur: comparison between locking plate and angle blade plate constructs

PURPOSE

Biomechanical properties of locking plate and angle blade plate constructs in opening-wedge distal femur osteotomy were compared, with special attention to the impact of opposite cortex breakage and buttressing.

METHODS

Forty-eight synthetic femora underwent a lateral opening-wedge distal femur osteotomy, which was fixed either with a locking plate or with an angle blade plate. Two main groups were constituted based on the integrity of the opposite medial cortex-intact medial cortex and fractured medial cortex (FMC). Axial compression and torsion tests were performed comparing stiffness of all bone-implant constructs. In the group FMC, a special subgroup has been tested taking into consideration the effect of placing an additional 6.5-mm cancellous screw buttressing the medial cortex. Statistical level of significance was fixed in 0.05 using a confidence interval of 95 %.

RESULTS

Intact medial cortex significantly increased the stiffness for both implants tested in this study. In the FMC group, angle blade plate constructs reached higher stiffness mean values for both torsion and axial compression. The insertion of a buttressing screw on the medial cortex increased the stiffness of all tested bone-plate constructs. This additional screw favoured mostly locking plate constructs implementing their stiffness to torsion to mean values comparable to those reached by angle blade plate constructs.

CONCLUSIONS

Angle blade plate constructs reached higher stiffness mean values than locking plates for both axial compression and torsion loads. The addition of a buttressing screw on the opposite cortex increased the stability of all bone-implant constructs to levels similar to those showed with an intact medial cortex. The present study findings support the clinical use of angle blade plates, alone or associated with a medial buttressing screw, as an alternative fixation method for supracondylar open-wedge osteotomies of the femur.

Midterm results following medial closed wedge distal femoral osteotomy stabilized with a locking internal fixation device

PURPOSE

Aim of this study was to evaluate the subjective and radiological outcome and to evaluate the complications of a medial closing wedge osteotomy at the femur for lateral osteoarthritis with genu valgum.

METHODS

Twenty-three patients with grade III to IV cartilage damage and valgus knee alignment were treated with medial closing wedge osteotomy at the distal femur. The osteotomy was stabilized with an internal plate fixator. Age varied between 25 and 55 years (mean 47 years). One patient was lost to final follow-up.

RESULTS

After 3.5 years, all Knee Osteoarthritis Outcome Score (KOOS) subitems increased significantly. There was no significant difference in the subgroup analysis of KOOS subitems for patients with and without microfracture or age (>50 vs. <50 years). There were no perioperative complications. One patient had an overcorrection. All, but one osteotomy, showed stable bone healing. There was a loss of correction due to delayed bone healing in one case. Possible explanations for this complication were injury of the lateral cortex or smoking. This case required revision with bone graft and an additional lateral plate. In no case, a conversion to an endoprosthesis was necessary.

CONCLUSION

The femoral medial closing wedge osteotomy is a surgical method for improving symptoms of lateral osteoarthritis in the valgus knee.

LEVEL OF EVIDENCE

IV.

Lateral Opening-wedge Distal Femoral Osteotomy: Pain Relief, Functional Improvement, and Survivorship at 5 Years

BACKGROUND

Distal femoral varus osteotomy may be used to treat valgus knee malalignment or to protect a knee compartment in which cartilage restoration surgery (such as osteochondral or meniscus allografting) has been performed. Medial closing-wedge osteotomy has demonstrated good success in treatment of osteoarthritis in published series, but few studies have evaluated distal femoral lateral opening-wedge osteotomy in terms of correction of deformity, pain and function, and survivorship.

QUESTIONS/PURPOSES

(1) Does lateral opening-wedge osteotomy lead to accurate correction? (2) What pain and function levels do patients experience after lateral opening-wedge osteotomy? (3) What are the nonunion, complication, and reoperation rates after lateral opening-wedge osteotomy?

METHODS

Between 2000 and 2010, we performed 40 distal femoral osteotomies. Two knees (two patients) underwent a medial closing-wedge osteotomy and were excluded from the present study. Thirty-eight knees (97%) in 36 patients were lateral opening-wedge varus-producing osteotomies; of those, 31 knees (82%) in 30 patients had followup at a minimum of 2 years (mean, 5 years; SD, 2; range, 2-12 years) and comprised the study population. The indications for osteotomy included symptomatic lateral compartment arthritis with clinical valgus deformity or a cartilage or meniscal defect in the lateral compartment with clinical valgus alignment. The study population was stratified into two groups based on reason for osteotomy: patients with isolated symptomatic lateral compartment arthritis (arthritis group; 19 knees [61%]) and patients who underwent joint preservation procedures including osteochondral allograft transplantation or meniscal allograft transplantation (joint preservation group; 12 knees [39%]). Data collection from our institution's osteotomy database included patient demographics, lower extremity coronal alignment, and operative details. Pain and function were measured preoperatively and postoperatively using the International Knee Documentation Committee (IKDC) score. Time to radiographic union, complications, and reoperations were recorded.

RESULTS

Twenty-one of 31 knees had postoperative radiographic data available for review. Of these, seven of 15 knees in the arthritis group and three of six knees in the joint preservation group were within the correction goal of ± 3° from neutral mechanical alignment. In the arthritis group, the mean IKDC total score improved from 47 (SD, 15) preoperatively to 67 (SD, 10) postoperatively. In the joint preservation group, the mean IKDC total score improved from 36 (SD, 12) preoperatively to 62 (SD, 18) postoperatively. One nonunion occurred in the arthritis group. No postoperative complications were experienced. Ten knees in the arthritis group and six knees in the joint preservation group had additional surgery after the osteotomy, consisting primarily of hardware removal, arthroscopy for cartilage-related conditions, or conversion to arthroplasty. Survivorship at 5 years, with conversion to arthroplasty as the endpoint, was 74% in the arthritis group and 92% in the joint preservation group.

CONCLUSIONS

Lateral opening-wedge distal femoral osteotomy was less accurate in correction of valgus deformity than expected, but the procedure was associated with improved knee pain and function scores. Our clinical and radiographic results are comparable to published series evaluating medial closing-wedge distal femoral osteotomy. Achieving our desired correction of ± 3° from neutral alignment was clinically difficult. An improved method of preoperative templating and refinement of the intraoperative technique may improve this. Future studies with more patients and longer followup will provide clarity on this topic.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Expanding the indications: distal femoral osteotomy used successfully to treat recurrent knee effusion

Distal femoral osteotomy (DFO) is successful in treating painful valgus arthritis of the knee. We present a case where painless recurrent knee effusion was attributed to constitutional valgus. The absence of pain made the indication for surgery atypical so DFO was carefully considered and planned. A small correction was performed, bringing alignment closer to neutral with complete resolution of the recurrent effusion. We suggest that the indications for knee osteotomy can be expanded to include recurrent joint effusion in carefully selected patients.

Distal femoral osteotomy

Osteotomies around the knee are well-recognized treatments for unloading the affected compartment in cases of lower limb malalignment. There are few papers in the literature describing the outcomes of distal femoral osteotomy (DFO), as compared with the studies reporting on high tibial osteotomy (HTO), probably because valgus malalignment is less common than the varus one. There is still debate as to what the correct indication is and which surgical techniques lead to the best outcomes in performing a DFO. Besides, it is still controversial whether patellofemoral arthritis should be considered as a contraindication to performing a DFO, as well as in HTO. In this article, we will summarize the indications for DFO, the surgical techniques reported in the literature, and their outcomes.

Fixed bearing lateral unicompartmental knee arthroplasty--short to midterm survivorship and knee scores for 101 prostheses

BACKGROUND

Isolated unicompartmental knee arthritis is less common laterally than medially. Lateral unicompartmental knee arthroplasty (UKA) constitutes only 1% of all knee arthroplasty performed. Use of medial UKA is supported by several published series showing good long-term survivorship and patient satisfaction, in large patient cohorts. Results of lateral UKA however have been mixed. We present the short and mid-term survivorship and 5-year clinical outcome of 101 lateral UKAs using a single prosthesis.

METHODS

Over a 9 year period, 100 patients who satisfied inclusion criteria underwent a lateral fixed-bearing unicompartmental arthroplasty. American Knee Society (AKSS), Oxford Knee (OKS) and modified Western Ontario McMaster Universities Arthritis Index (WOMAC) scores were completed preoperatively and at 1, 2 and 5 years postoperatively. Kaplan-Meier survival analysis was used to determine the 2-year and 5-year survivorship, using revision for any cause as end point.

RESULTS

Survivorship was 98.7% and 95.5% at 2 and 5 years respectively. 1 knee was revised for subsidence of the tibial component and 1 knee for progression of medial compartment osteoarthritis. Of a possible 35 knees in situ at 5 year follow-up, 33 knees were fully scored. Median AKSS, OKS and modified WOMAC scores were 182, 41, and 16 respectively.

CONCLUSIONS

The mid-term survivorship and outcome scores at 5-years suggest that lateral unicompartmental knee arthroplasty provides a valuable alternative to total joint replacement in selected patients with isolated lateral tibio-femoral arthritis at mid-term follow-up. Level II evidence.

Opening wedge distal femoral varus osteotomy for lateral compartment osteoarthritis in the valgus knee

INTRODUCTION

Osteotomy aims to reduce pain and the rate of progression of arthritis by correcting deformity and offloading the affected compartment. This study reports the results of a case series of opening wedge distal femoral varus osteotomies for valgus lateral osteoarthritis of the knee.

PATIENTS AND METHODS

Eighteen patients underwent osteotomy surgery (21 knees) with the aim of correcting the mechanical axis to 48-50% from medial to lateral.

RESULTS

The mean follow-up for the study population was 4.5 years (range 1.6 to 9.2 years). Four patients underwent conversion to arthroplasty at a mean time of 3.3 years postosteotomy. Kaplan-Meier analysis demonstrates a cumulative survival of 79% at 5 years. In the remaining 17 osteotomies, all patients reported that outcome measures improved from baseline. However, only the IKDC and pain subdomain of KOOS showed a statistically significant and clinically relevant difference. Re-operation for non-arthroplasty related surgery was common. In part this was due to symptoms related to prominence of metalwork (10). Other reasons included non-union (1), loss of correction (2), infection (1), and persistent symptoms (2).

CONCLUSION

Cumulative survival of opening wedge DFVO is comparable with that reported in closing wedge series. Clinically relevant differences in the IKDC and KOOS pain scores suggest that opening wedge DFVO is a useful option in the management of valgus gonarthrosis. However, DFVO is a technically demanding procedure and re-operation, particularly for removal of metalwork, is common.