Radiographic evaluation of tibial component alignment in total knee arthroplasty following extramedullary and intramedullary tibial referencing

Background: Long term survivorship of total knee arthroplasty (TKA) is significantly dependant on prostheses alignment. The debate on optimal referencing for femoral component is largely resolved with Intra-medullary jigs reproducing superior alignment. However there is still a contention about whether intramedullary or extramedullary jigs are better for tibial referencing. This study aims to compare the accuracy of tibial component alignment in TKA using intramedullary and extramedullary tibial referencing jigs.Methods: Between December 2012 and September 2014, 66 primary conventional cemented TKAs were performed using Nexgen-LPS Flex (Zimmer) implants in 55 patients, 50-80 y old (mean 65.54 y) with osteoarthritis/rheumatoid arthritis. Intramedullary and extramedullary tibial referencing was used in alternate patients undergoing TKA after excluding patients with BMI >35 kg/m2, knee deformity >150,excessive tibial bowing, previous fractures/surgeries/retained metalwork around knee. Postoperatively, tibial component alignment (TCA) in coronal plane was assessed using AP radiograph of leg. A 3º cutoff from neutral mechanical axis (i.e., 90o±3o) was considered acceptable.Results: The intramedullary group (n=33) had 4 outliers (TCA >93º or <87º) whereas the extramedullary group (n=33) had 7 outliers (p=0.511). The difference in mean TCA between intramedullary and extramedullary groups was not statistically significant [90.70±2.43 and 90.55±2.17 (p=0.790)]. There were no significant per-operative/post-operative complications in either group.Conclusions: We conclude that both intramedullary and extramedullary tibial referencing guides can be used to achieve desired tibial component alignment (90±3º) in TKA. However the surgeon should appreciate the benefits and deficiencies of either types of tibial referencing and use whichever is suited in a particular case.

Incidence of patella baja following patellar eversion in total knee arthroplasty

Background: Patella baja is a rare complication of total knee arthroplasty (TKA) leading to decreased mechanical advantage of the extensor mechanism, decreased knee range of motion, anterior knee pain and increased wear of the tibial and patellar polyethylene. There exists a lack of evidence on whether patellar eversion leads to shortening of the patellar tendon. The present study aims to determine if eversion of patella during TKA leads to patella baja.Methods: Between August 2014 and August 2016, 55 knees undergoing primary TKA with a standard medial parapatellar arthrotomy and eversion of patella were included in this two point cross sectional study. Preoperative X-rays were taken to assess the length of the patellar tendon and Insall Salvati ratio (ISR). Postoperatively the Blackburne Peel Index (BPI), ISR and patellar tendon lengths were assessed on lateral X-rays to look for any incidence of patella baja.Results: The postoperative change in the length of the patellar tendon was unpredictable; though most of them decreased. The pre and post op difference in the length of patellar tendon was statistically significant in females (4.43±0.20 cm vs. 4.35±0.24 cm; p value-0.005). Significant decrease in length of patellar tendon was seen in patients aged 66-70 years (p= 0.024) and patients with BMI >30 kg/m2. No case of true patella baja was found postoperatively. No significant correlation could be established between ISR and age, sex or BMI of the patients.Conclusions: The different risk factors for post TKA shortening of patellar tendon include female gender and higher BMI (>30 Kg/m²). However eversion of patella during TKA may not lead to an increased incidence of true patella baja

Management of infected non-union of lower limb long bone fractures using ilizarov technique: a study of outcomes

Background: Nonunion of long bone fractures is a common condition treated by an orthopaedic surgeon. Many nonunions can be treated effectively by internal fixation with or without bone grafting but, an infected nonunion can prove to be a tough challenge. The Ilizarov method is effective in managing infected nonunion of long bones. This study aims to assess the outcome of management of infected nonunions of long bones of lower limb with Ilizarov Ring fixator using bone and functional results as per Association for the Study and Application of Methods of Ilizarov (ASAMI) Scoring System.Methods: We retrospectively analysed 18 patients (16 Male: 2 Female; Mean age 43.2 years) managed with Ilizarov technique for an infected tibial or femoral nonunion between 01 January 2013 and 31 December 2014. They were followed up for an average of 25.4 months after removal of fixator. They were assessed for functional and Bone (radiological) outcomes using the Association for the Study and Application of Methods of Ilizarov (ASAMI) criteria.Results: 17 limbs were salvaged and union could be achieved. One limb required amputation due to severe persistent intractable infection. None required any additional skeletal stabilisation after removal of fixator frame except casting in a few patients for a period of 6 weeks. Mean time to union was 211.83 days (range 136 - 320days/median 184) or 7.01 months. As per the ASAMI score, Bone results were excellent in 10, good in 5, fair in 2 and poor in 1. Functionally 7 were graded as excellent, 6 as good, 3 as fair and 1 as poor and 1 patient underwent amputation.Conclusions: The Ilizarov’s method remains one of the most versatile and successful means of achieving bone healing in infected nonunions of long bones of lower limbs with additional benefits of correcting bone defects, deformities and limb length inequalities.

Comparative study between proximal femoral nail and proximal femoral nail antirotation in management of unstable trochanteric fractures

Background: In the management of peri-trochanteric fractures, intramedullary (IM) devices have proven advantage over extramedullary devices. IM devices allow for stable anatomical fixation of more comminuted fractures without shortening the abductor lever arm or changing the proximal femoral anatomy. Between IM devices like proximal femoral nail (PFN) and proximal femoral nail antirotation (PFNA), the helical blade of latter is believed to provide stability, compression and rotational control of the fracture with higher cut out strength. The following study was undertaken in an attempt to compare these two types of Intra-medullary devices.Methods: Between January 2012 and June 2013, 50 patients with unstable intertrochanteric fractures fulfilling inclusion and exclusion criteria, were randomized into 2 groups to undergo CRIF with either standard PFN (n=25) or PFNA (n=25). They were compared in terms of demography, per-operative variables and postoperative parameters including functional evaluation till 1year postoperatively.Results: Background demographic variables, fracture type and pre-injury ambulatory status were comparable between the groups. Operative duration of surgery, amount of blood loss and number of fluoroscopic images were significantly lower in PFNA group as compared to PFN group. Post op complications like infection, non-union, cut out/z-effect, loss of reduction, re-operation and mortality rates didn’t differ significantly between the groups. Post op functional recovery as evaluated by pain, use of walking aids and Harris hip scores were similar in both groups. Conclusions: PFNA significantly reduces the operative time, amount of blood loss and fluoroscopic imaging as compared to PFN. However PFNA offers no significant benefits over PFN in terms of post-operative functional recovery or complications

Rotational malalignment after closed intramedullary nailing of femoral shaft fractures and its influence on functional outcome

Background: Rotational malalignment after closed intramedullary nailing of femoral shaft fractures is one of the most common complication. Data on functional outcome of such rotational malalignment particularly in an Asian population is lacking. This cross sectional study intends to determine the prevalence of rotational malalignment occurring after intramedullary nailing of femoral shaft fractures using CT scans and also compare this with femoral malrotation detected by clinical methods. The study also aims to analyze the effect of such femoral malrotation on functional outcome.  Methods: 81 patients who underwent closed IM nailing of femoral shaft fractures were reviewed after fracture union. The rotational malalignment was measured using CT scans and clinical methods. CT based torsional deformity >15° were considered significant. Functional outcome was assessed using Harris hip score (HHS), lower extremity functional scale (LEFS) and WOMAC osteoarthritis index for knee.Results: On CT 30 (37%), 24 (29.6%) and 27 (33.33%) patients had rotational malalignment of <10°, 10°-14° and >15° respectively. This was independent of the fracture location, fracture type, implant design or metallurgy. The clinical method of assessing femoral rotation was less accurate (sensitivity 18.52% and specificity of 79.63%) as compared to CT method though not statistically significant. However LEFS (P=0.009) and WOMAC (P=0.033) scores were statistically poorer in patients with true rotational malalignment (≥15°). However no significant difference was noted between the groups in HHS. Patients with external and internal rotation deformities had comparable functional results.Conclusions: In this study, true rotational malalignment (>15°) after closed intramedullary nailing of femoral shaft fractures was found in 33.33% of patients. This is independent of fracture location, fracture type, implant design or implant metallurgy. Torsional deformities of femur >15° affect knee and lower limb function as a whole. External and internal rotational deformities perform equally.