Factors Correlated with the Reducibility of Varus Deformity in Knee Osteoarthritis: An Analysis Using Navigation Guided TKA

Background

We hypothesized that a number of clinical and radiologic parameters could influence the reducibility of varus deformity in total knee arthroplasty. The aim of this study was to identify the factors correlated with reducibility of varus deformity and predict more accurately the amount of medial soft tissue release required in varus deformity total knee arthroplasty.

Methods

One hundred forty-three knees with preoperative varus alignment and medial osteoarthritis were included in this retrospective study. The total knee arthroplasties were performed using a navigation system (OrthoPilot) by single surgeon. To assess varus deformity, the authors measured preoperative mechanical axis angles and valgus stress angles. Mechanical tibial angles, mechanical femoral angles, femoral osteophyte sizes, and tibial osteophyte sizes were measured. The Ahlbäck grading scale was applied for radiologic parameters, and clinical parameters (age, body mass index, sex, duration of pain, and preoperative range of motion) were documented. Correlations between these factors and preoperative valgus stress angle were analyzed.

Results

A negative correlation was found between preoperative mechanical axis angle and preoperative valgus stress angle (p < 0.01, r = -0.38), and a positive correlation was found between the preoperative mechanical tibial angle and preoperative valgus stress angle (p = 0.01, r = 0.19).

Conclusions

The present study shows that preoperative varus deformity and proximal tibial vara (measured by preoperative mechanical axis angle and mechanical tibial angle, respectively) are correlated with reducibility of varus deformity (measured by preoperative valgus stress angle), and clinical parameters (age, range of motion, duration of pain and body mass index) and other radiologic parameters (osteophyte size, severity of osteoarthritis and angulation of distal femoral joint surface) were not significantly correlated with reducibility of varus deformity.     

Accuracy of Individualized Custom Tibial Cutting Guides in UKA

Background

Component malposition is one of the major reasons for early failure of unicompartmental knee arthroplasty (UKA).

Questions/Purposes

It was investigated how reproducibly patient-specific instrumentation (PSI) achieved preoperatively planned placement of the tibial component in UKA specifically assessing coronal alignment, slope and flexion of the components and axial rotation.

Patients and Methods

Based on computer tomography models of ten cadaver legs, PSI jigs were generated to guide cuts perpendicular to the tibial axis in the coronal and sagittal planes and in neutral axial rotation. Deviation ≥3° from the designed orientation in a postoperative CT was defined as outside the range of acceptable alignment.

Results

Mean coronal alignment was 0.4 ± 3.2° varus with two outliers. Mean slope was 2.8 ± 3.9° with six components in excessive flexion. It was noted that the implants were put in a mean of 1.7 ± 8.0° of external rotation with seven outliers

Conclusions

PSI helped achieve the planned coronal orientation of the component. The guides were less accurate in setting optimal tray rotation and slope.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-014-9410-z) contains supplementary material, which is available to authorized users.     

Fibula-related complications during bilateral tibial lengthening: 60 patients followed for mean 5 years

Background and purpose

Complications related to the fibula during distraction osteogenesis could cause malalignment. Most published studies have analyzed only migration of the fibula during lengthening, with few studies examining the effects of fibular complications.

Patients and methods

We retrospectively reviewed 120 segments (in 60 patients) between 2002 and 2009. All patients underwent bilateral tibial lengthening of more than 5 cm. The mean follow-up time was 4.9 (2.5–6.9) years.

Results

The average lengthening percentage was 34% (21–65). The ratio of mean fibular length to tibial length was 1.05 (0.91–1.11) preoperatively and 0.83 (0.65–0.95) postoperatively. The mean proximal fibular migration (PFM) was 15 (4–31) mm and mean distal fibular migration (DFM) was 9.7 (0–24) mm. Premature consolidation occurred in 10 segments, nonunion occurred in 12, and angulation of fibula occurred in 8 segments after lengthening. Valgus deformities of the knee occurred in 10 segments.

Interpretation

PFM induced valgus deformity of the knee, and premature consolidation of the fibula was associated with the distal migration of the proximal fibula. These mechanical malalignments could sometimes be serious enough to warrant surgical correction. Thus, during lengthening repeated radiographic examinations of the fibula are necessary to avoid complications.Extensive lower limb lengthening often introduces complications including genu varum, genu valgum, tibia vara, ankle varus, and ankle valgus which may require another surgical correction (Barreto et al. 2007).Soft tissue-resisting forces during the lengthening of bone are responsible for most of the complications. The resisting forces can be soft tissues, interosseus membrane, or bone itself in tibial distraction (Saleh et al. 2002, Hatzokos et al. 2004, Shyam et al. 2009). These resisting forces produce a drag effect on the fibula and hence there is decreased distraction, which is responsible for complications such as tibial axial deviation, and distraction at the proximal and distal tibiofibular joints. Several studies have found migration of the proximal and distal fibula during lengthening (Saleh et al. 2002, Hatzokos et al. 2004) but there is no clinical research regarding long-term outcome of the complications of the fibula itself such as premature consolidation, nonunion, and angulation. In an earlier study (Shyam et al. 2009), we reported increased knee laxity and valgus angulation of the tibia due to proximal fibular migration. In the present study of 120 lengthened tibial segments, we have investigated whether the various complications of the fibula affected the axial limb alignment and had a bearing on the joint-related complications.     

Endstage arthritis following tibia plateau fractures: average 10-year follow-up

Background

Patients with tibial plateau fractures are believed to have an increased risk for posttraumatic arthritis that may require reconstructive surgery. The incidence of this problem is, however, unknown. We sought to determine the average 10-year incidence of posttraumatic arthritis necessitating reconstructive surgery following tibia plateau fractures.

Methods

We used data from our orthopedic trauma database to identify patients with operatively treated tibia plateau fractures. Their cases were cross-referenced with the data from our province’s administrative health database and tracked over time for the performance of reconstructive knee surgery. The average follow-up was 10 years.

Results

There were 311 tibial plateau fractures treated at our institution between 1987 and 1994. The 10-year Kaplan–Meier survival analysis for the primary outcome of endstage arthritis was 96%. Analysis of the secondary outcome measure, specifically surgeries for what was thought to be “minor arthritis,” revealed a 10-year Kaplan–Meier survival of 87%.

Conclusion

Our findings may be used to counsel patients who require surgical treatment of tibia plateau fractures about the long-term risk of requiring reconstructive knee surgery for endstage arthritis in the knee.     

The Huntington procedure: still a reasonable option for large tibial defects in paediatric patients

Background

Management of gap nonunion of tibia is technically difficult, time consuming, physically and psychologically demanding for the patient with unpredictable results. Various techniques have been described in literature for the treatment of gap nonunions, but each one has its own limitations.

Purpose

This study reports the outcomes of ipsilateral fibular transposition for reconstruction of tibial defects in paediatric age group.

Methods

We retrospectively reviewed records of 14 patients who underwent surgery for gap nonunion tibia with ipsilateral tibialization of fibula. Fibula is transferred to tibia as pedicle graft in two-staged procedure. Due to retained blood supply to one end of the transplant, the graft easily takes up and hypertrophies upon weight bearing over a period of time.

Results

Average time of radiographic union was 13.35 weeks. Guarded partial weight bearing was started at an average of 16.5 weeks with gradual progression to full weight bearing. The leg length discrepancy at final follow-up ranged from 0 to 7 cms with an average of 2.60 cms. Hypertrophy of tibialized fibula was observed in all patients, with 8 patients showed grafted fibula reaching the diameter of opposite tibia. On subjective assessment, 9 patients were highly satisfied, 4 patients were satisfied and one patient was dissatisfied with the procedure.

Conclusions

Huntington procedure is a simple, cost-effective and easy procedure for large tibial defects in paediatric patients which does not require any specialized team and implants, and can be performed in moderately equipped hospital. Leg length discrepancy may be addressed, after the transferred fibula is well developed.     

An in vitro comparison of tibial tray cementation using gun pressurization or pulsed lavage

Purpose

Aseptic loosening of the tibial component remains a limitation to the highly successful procedure of total knee arthroplasty (TKA). Pulsed lavage improves bone cement penetration and interface strength in tibial tray cementation. This study tested whether pressurized cement application with a cement gun can compensate the use of jet lavage for bone surface preparation.

Methods

Tibial components were implanted in six pairs of cadaveric tibiae. On one side, pulsed lavage of the tibial bone was combined with finger packing of bone cement; on the other side, syringe lavage and gun cementing was used. Cement penetration into the bone was determined from computed tomography scans, and Interface strength was determined by pull-out testing.

Results

Cement penetration was greater (p = 0.004) and interface strength was higher (p = 0.028) in the pulsed lavage group.

Conclusion

Pressurization of cement by gun application could not compensate for the omission of pulsed lavage. Thus, pulsed lavage should be considered a crucial factor in TKA to improve implant fixation, which cannot be compensated for by cement application technique.     

The Influence of Tibial Positioning on the Diagnostic Accuracy of Combined Posterior Cruciate Ligament and Posterolateral Rotatory Instability of the Knee

Background

To determine if tibial positioning affects the external rotation of the tibia in a dial test for posterolateral rotatory instability combined with posterior cruciate ligament (PCL) injuries.

Methods

Between April 2007 and October 2007, 16 patients with a PCL tear and posterolateral rotatory instability were diagnosed using a dial test. The thigh-foot angle was measured at both 30° and 90° of knee flexion with an external rotation stress applied to the tibia in 2 different positions (reduction and posterior subluxation). The measurements were performed twice by 2 orthopedic surgeons.

Results

In posterior subluxation, the mean side-to-side difference in the thigh-foot angle was 11.56 ± 3.01° at 30° of knee flexion and 11.88 ± 4.03° at 90° of knee flexion. In the sequential dial test performed with the tibia reduced, the mean side-to-side difference was 15.94 ± 4.17° (p < 0.05) at 30° of knee flexion and 16.88 ± 4.42° (p = 0.001) at 90° of knee flexion. The mean tibial external rotation was 5.31 ± 2.86° and 6.87 ± 3.59° higher in the reduced position than in the posterior subluxation at both 30° and 90° of knee flexion.

Conclusions

In the dial test, reducing the tibia with an anterior force increases the ability of an examiner to detect posterolateral rotary instability of the knee combined with PCL injuries.     

Preoperative surgical planning versus navigation system in valgus tibial osteotomy: a cross-sectional study

Purpose

The objective of this study was to verify whether the correction obtained using a navigation system (NS) corresponds to the wedge calculated by the Dugdale method (DM) in high tibial osteotomy (HTO).

Methods

We included 17 patients with primary varus and HTO indication, consecutively admitted to a public university hospital. All patients underwent panoramic radiography with bipedal load for the wedge calculation by DM. They underwent HTO with an opening wedge, fixed with an HTO plate and monitored by the OrthoPilot NS. Bone grafts were used in every case. The wedge opening obtained by the NS was compared to that calculated in the radiographs.

Results

The mean opening by DM was 9.53° and by the NS 11.8° (p < 0.045).

Conclusions

There was a significant difference in the calculation of the wedge opening between the DM and NS. HTO without the aid of the NS could theoretically lead to undercorrection of the deformity.     

The use of external fixation combined with vacuum sealing drainage to treat open comminuted fractures of tibia in the Wenchuan earthquake

Purpose

The purpose of this study was to review the results of external fixation combined with vacuum sealing drainage (VSD) to treat patients who sustained tibial and fibular fractures in the Wenchuan earthquake.

Methods

We retrospectively analysed 179 cases (of which 85 were classified as Gustilo grade III) of open comminuted fracture of the tibia and fibula caused by the Wenchuan earthquake. The patients were followed up for an average of 15 months; detailed records were kept on their function and recovery.

Results

After caring for the life-threatening injuries; fractures were treated by external fixation, with VSD used on the surface or in the cavity of the wound after debridement. Antibiotics were administered on the basis of drug sensitivity test results. After the infection had been controlled and healthy granulation tissue had developed, the patients underwent secondary suture, free skin grafting, or skin flap transfer.

Conclusion

Good results can be achieved when external fixation combined with vacuum sealing drainage were used to treat open comminuted fractures of tibia and fibula in the Wenchuan earthquake.     

An unusual stress fracture: Bilateral posterior longitudinal stress fracture of tibia

INTRODUCTION

Stress fractures (SF) occur when healthy bone is subjected to cyclic loading, which the normal carrying range capacity is exceeded. Usually, stress fractures occur at the metatarsal bones, calcaneus, proximal or distal tibia and tends to be unilateral.

PRESENTATION OF CASE

This article presents a 58-year-old male patient with bilateral posterior longitudinal tibial stress fractures. A 58 years old male suffering for persistent left calf pain and decreased walking distance for last one month and after imaging studies posterior longitudinal tibial stress fracture was detected on his left tibia. After six months the patient was admitted to our clinic with the same type of complaints in his right leg. All imaging modalities and blood counts were performed and as a result longitudinal posterior tibial stress fractures were detected on his right tibia.

DISCUSSION

Treatment of tibial stress fracture includes rest and modified activity, followed by a graded return to activity commensurate with bony healing. We have applied the same treatment protocol and our results were acceptable but our follow up time short for this reason our study is restricted for separate stress fractures of the posterior tibia.

CONCLUSION

Although the main localization of tibial stress fractures were unilateral, anterior and transverse pattern, rarely, like in our case, the unusual bilateral posterior localization and longitudinal pattern can be seen.     

Utility of Preoperative Distractive Stress Radiograph for Beginners to Extent of Medial Release in Total Knee Arthroplasty

Background

This study evaluated the preoperative distractive stress radiographs in order to quantify and predict the extent of medial release according to the degree of varus deformity in primary total knee arthroplasty.

Methods

We evaluated 120 varus, osteoarthritic knee joints (75 patients). The association of the angle on the distractive stress radiograph with extent of medial release was analyzed. The extent of medial release was classified into the following 4 groups according to the stage: release of the deep medial collateral ligament (group 1), release of the posterior oblique ligament and/or semimembranous tendon (group 2), release of the posterior capsule (group 3) and release of the superficial medial collateral ligament (group 4).

Results

The mean femorotibial angle on the preoperative distractive stress radiograph was valgus 2.4° (group 1), valgus 0.8° (group 2), varus 2.1° (group 3) and varus 2.7° (group 4). The extent of medial release increased with increasing degree of varus deformity seen on the preoperative distractive stress radiograph.

Conclusions

The preoperative distractive stress radiograph was useful for predicting the extent of medial release when performing primary total knee arthroplaty.     

Hydroxyapatite (HA) coating appears to be of benefit for implant durability of tibial components in primary total knee arthroplasty

Background

It is unclear whether there is a clinical benefit to adding hydroxyapatite (HA) coatings to total knee implants, especially with the tibial component, where failure of the implant more often occurs. A systematic review of the literature was undertaken to identify all prospective randomized trials for determining whether the overall clinical results (as a function of durability, function, and adverse events) favored HA-coated tibial components.

Methods

A comprehensive literature search was performed for the years 1990 to September 16, 2010. We restricted our search to randomized controlled trials involving participants receiving either an HA-coated tibia or other forms of tibial fixation. The primary outcome measures evaluated were durability, function, and acute adverse events.

Results

Data from 926 evaluable primary total knee implants in 14 studies were analyzed. Using an RSA definition for durability, HA-coated tibial components (porous or press-fit) without screw fixation were less likely to be unstable at 2 years than porous and cemented metal-backed tibial components (RR = 0.58, 95% CI: 0.34–0.98; p = 0.04, I² = 39%, M-H random effects model). There was no significant difference in durability, as measured from revision and evaluated at 2 and 8–10 years, between groups. Also, functional status using different validated measures showed no significant difference at 2 and 5 years, no matter what measure was used. Lastly, there was no significant difference in adverse events. Limitations included small numbers of evaluable patients (≤ 50) in 7 of the 14 trials identified, and a lack of “hard” evidence of durability with need for replacement (i.e. frank failure, pain, or loss of functionality).

Interpretation

In patients > 65 years of age, an HA-coated tibial implant may provide better durability than other forms of tibial fixation. Larger trials should be undertaken comparing the long-term durability, function, and adverse events of HA-coated implants with those of other porous-coated tibial implants in younger, more active OA patients.