Standard Medial Parapatellar Arthrotomy Research Articles

Influence of prosthetic joint line position on outcome after total knee replacement

<p class="abstract"><strong>Background:</strong> The current study had been designed so as to assess whether joint line elevation and change in patellar tendon length influences knee flexion after primary cruciate retaining TKR.</p><p class="abstract"><strong>Methods:</strong> This prospective study involved patients with advanced degenerative joint disease involving one or both knees who presented to the outpatient department of a tertiary care hospital. Exclusion criteria were any prior knee surgery. Surgery was performed under tourniquet with standard medial para-patellar arthrotomy to expose all our knees. In the study radiological assessment was done by true lateral X-ray view of knee in 30 degree of flexion. We choose Caton-Deschamps indices (CI) for diagnosis of post TKR patella infera and joint line elevation. CI<0.6 was defined as patella infera (normal range of CI 0.60-1.45). After all data collection comparison was done between joint line elevation versus without joint line elevation patients (with/without patellar tendon shortening) range of movement.<strong></strong></p><p class="abstract"><strong>Results:</strong> Total of 100 patients (72 females and 28 males) with 176 knees (bilateral=76, unilateral=24) who fulfilled the above said criteria involved in study. The mean age of the patients at the time of surgery was 64.4 years with range of 54 years to 80 years. The average follow up of 24 months, with minimum follow up of 18 months. Average range of motion (ROM) in NO Joint line elevation/patella tendon shortening patient measured 107.2<sup>°</sup>, and joint line elevation with patellar tendon shortening (prior patella infera) and joint line elevation without patella tendon shortening(prior patella infera) patient average ROM was measured 86.7 and 87.8 degree respectively.</p><strong>Conclusions:</strong> In our study patellar tendon shortening and joint line elevation reduces ROM knee. Mechanical factors also explain the association between joint line elevation and patellar tendon length with range of motion. Reduction in length of extensor apparatus reduces the range of flexion.

Incidence of patella baja following patellar eversion in total knee arthroplasty

<p class="abstract"><strong>Background:</strong> 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.</p><p class="abstract"><strong>Methods:</strong> 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.<strong></strong></p><p class="abstract"><strong>Results:</strong> 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/m<sup>2</sup>. 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.</p><p><strong>Conclusions:</strong> 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.</p>

Intraoperative Adductor Canal Block for Augmentation of Periarticular Injection in Total Knee Arthroplasty: A Cadaveric Study

BackgroundFunction is often sacrificed for pain control after total knee arthroplasty. Motor-sparing blocks, including adductor canal block (ACB) and periarticular injection (PAI), have gained interest to address this compromise. Our study evaluates the anatomic feasibility, accuracy, and safety of intraoperative ACB as an adjunct to PAI by analyzing 3 different injection orientations and needle configurations. MethodsEleven cadaveric knees underwent a standard medial parapatellar arthrotomy. Blunt dissection through the suprapatellar recess was performed. Using a 10-mL syringe, various colors of dyed liquid gelatin were injected toward the proximal and distal adductor canal (AC) using 3 needle configurations. Medial dissection of the knee for each specimen was performed. The position of each needle and location of injected dye was identified and described relative to the AC. ResultsAccuracy of each injection orientation and/or needle configuration was different: 86% for a blunt needle in the distal AC, 57% for blunt needle in the proximal AC, and 14% for a spinal needle in the proximal AC. Puncture of the femoral artery was observed with the spinal needle 43% of the time and had the closest average proximity to the femoral artery with a distance of 5.9 mm. There were no vascular punctures using blunt needles, and the average distance from the femoral artery with proximal and distal orientation was 10.2 mm and 15.4 mm, respectively. ConclusionIntraoperative ACB augmentation of PAI appears to be anatomically feasible and safe. There was decreased accuracy and increased risk of vascular puncture using a 3.5-inch spinal needle. A blunt 1.5-inch needle directed toward the distal AC had the highest accuracy while minimizing vascular injury.

Avoidance of patellar eversion improves range of motion after total knee replacement: a prospective randomized study

Minimally invasive surgery has recently been introduced in TKA surgery. The purpose of this study was to evaluate the effect of eversion of the patella, on safety and functional result after TKA. In a prospective, randomised, double blinded trial, 60 patients were divided in two groups: group A underwent TKA through a standard medial parapatellar arthrotomy, with patellar eversion. Group B underwent the same exposure, except for the fact that the patella was subluxed laterally. All other treatment protocols were identical. Outcomes were measured until 1 year postoperatively. Radiographic evaluation included AP, lateral, skyline and full leg standing radiographs. VAS, WOMAC score, Knee Society Knee and Function score were performed. Active and passive range of motion (ROM) and knee proprioception was measured. All patients underwent isokinetic strength testing. The mean passive ROM changed from 121 degrees preoperatively to 121 degrees postoperatively in group A, compared to 118 degrees -131 degrees respectively in group B at 1 year (P = 0.003). The mean active ROM changed from 112 degrees to 115 degrees in group A, and from 108 degrees to 125 degrees in group B (P = 0.005). All other parameters were not significantly different. Patellar dislocation without eversion for exposing the knee during TKA is a safe procedure and improves ROM at 1 year postoperatively.

The Mini-Incision Mid-Vastus Approach for Total Knee Arthroplasty

Rapid functional recovery and improved range of motion after total knee arthroplasty (TKA) without compromising implant position. Osteoarthritis of the knee requiring TKA. Preoperative flexion < 80 degrees. Flexion contracture > 20 degrees. Body mass index > 40 kg/m(2). Fixed valgus deformity > 15 degrees. Relative: previous open surgery on the knee; systematic steroids (skin fragility); tall muscular males. Straight skin incision over the medial third of the patella from 2 cm proximal to the patella, and then to the level of the tibial tuberosity. Extension of capsular incision 2 cm into the vastus medialis muscle from a point 2 cm proximal to the patella. Deep incision around the medial border of the patella and distally to the level of the tibial tuberosity. The patella is displaced laterally but is not everted in flexion. Knee flexion and extension as necessary to move the soft-tissue surgical window for proximal or distal exposure. Hyperflexion of the knee only for insertion of the tibial component. Knee flexion exercises extension/flexion 0-0-70 degrees using continuous passive motion the day after surgery. Weight bearing to tolerance allowed at 1st day after surgery (walker, two crutches). Thrombosis prophylaxis. 69 patients with 74 TKAs done through the mini-incision mid-vastus approach were available with a minimum 1-year follow-up. A control group was evaluated retrospectively including 52 patients with 57 total knee replacements in which a standard medial parapatellar arthrotomy with patella eversion was used. At all clinical evaluations flexion and the ability to climb stairs were significantly superior in the mid-vastus group indicating a faster recovery and return to functional activities. There were no complications and the radiographic evaluation found no implant or limb malalignment, or signs of early loosening.

Sub-vastus approach versus the medial parapatellar approach in primary total knee: a randomised controlled trial [ISRCTN44544446

BackgroundThirty thousand knee replacements are performed annually in the UK. There is uncertainty as to the best surgical approach to the knee joint for knee arthroplasty. We planned a randomised controlled trial to compare a standard medial parapatellar arthrotomy with sub-vastus arthrotomy for patients undergoing primary total knee arthroplasty in terms of short and long term knee function.MethodsPatients undergoing primary total knee arthroplasty at the local NHS Trust are to be recruited into the study. Patients are to be randomised into either the subvastus or medial parapatellar approache to knee arthroplasty. The primary outcome measures will be the American Knee Society and WOMAC Scores. The secondary outcome measures will be patient based measures of EuroQol and SF-36. All outcomes will be measured pre-operatively, 1, 6, 12 and 52 weeks post-operatively. We will also review pain intensity using a pain and analgesia diary. Ease of surgical exposure and complications will also be analysed.DiscussionEvidence is lacking concerning the best surgical approach to the knee joint for patients undergoing primary total knee replacement. This pragmatic randomised trial tests the hypothesis that the sub-vastus approach is significantly superior to the standard medial parapatellar approach in terms of short and long term knee function.

Subvastus approach for total knee arthroplasty: A prospective, randomized, and observer-blinded trial

A prospective, randomized, and blinded trial was conducted with 89 consecutive primary knee arthroplasties comparing standard medial parapatellar arthrotomy with the subvastus approach. All patients received the same prosthesis (Insall-Burstein II) inserted by one surgeon using an identical technique with the only difference being the approach. The parapatellar approach (group I) was used in 43 knees, and in the remaining 46 knees the subvastus approach (group II) was used. Assessment revealed significantly earlier return of straight-leg raise (3.2 days vs 5.8 days, P <.001), lower consumption of opiates in the first week (78 mg vs 102 mg, P <.001), less blood loss (527 mL vs 748 mL, P <.001), and greater knee flexion at 1 week (78° vs 55°, P <.001) in group II (subvastus approach). The subvastus approach offers early advantages over the standard parapatellar arthrotomy. It preserves the integrity of the vastus medialis and peripatellar plexus of vessels. We advise its wider use in primary total knee arthroplasty.

Simultaneous femoral osteotomy and total knee arthroplasty for treatment of osteoarthritis associated with severe extra-articular deformity.

In the presence of large extra-articular deformity, complex imbalance of the collateral ligaments may result if standard techniques of soft-tissue releases and intra-articular bone resection are used during total knee arthroplasty. The purpose of this paper is to review our experience with simultaneous corrective osteotomy and total knee arthroplasty for the treatment of severe extra-articular femoral deformity associated with ipsilateral osteoarthritis of the knee. The results of simultaneous corrective osteotomy and total knee arthroplasty in eleven knees with osteoarthritis and associated extra-articular angular deformity of the femur were reviewed retrospectively. The femoral deformity resulted from fracture malunion in ten knees and from hypophosphatemic rickets in one. There were five primarily uniplanar deformities (four varus deformities and one antecurvatum deformity), five biplanar (varus and antecurvatum) deformities, and one triplanar (varus, antecurvatum, and internal rotation) deformity. Four knees were approached through a standard medial parapatellar arthrotomy and seven, through an anterolateral subvastus approach with an osteotomy of the tibial tubercle. The site of the femoral osteotomy was fixed with a blade-plate in seven patients, a press-fit long-stemmed femoral component in two, and a retrograde femoral nail in two. An extramedullary alignment system was utilized in eight patients, and intramedullary alignment was used in three. The duration of follow-up averaged forty-six months (range, twenty-six to eighty-eight months). According to the classification system of the Knee Society, the mean function score increased from 22 points preoperatively to 81 points at the time of follow-up and the mean knee score increased from 10 points preoperatively to 87 points at the time of follow-up. The mean flexion contracture decreased from 19 degrees preoperatively to 2 degrees at the time of follow-up. The arc of motion averaged 56 degrees (range, 30 to 75 degrees) preoperatively and 89 degrees (range, 65 to 115 degrees) at the time of follow-up. The mechanical alignment in the coronal plane was restored to within 2 degrees of normal in each patient. Ten femoral osteotomy sites healed, and one, in a patient treated with a press-fit long-stemmed femoral component, had not healed by the time of follow-up. All seven sites of the tibial tubercle osteotomies healed. There were no complete radiolucent lines at the prosthetic interfaces, and no total knee arthroplasty was revised. One patient had a nonfatal postoperative pulmonary embolism. As determined by clinical examination and the patients' assessment of function, no ligament imbalance was noted at the time of the most recent follow-up. Simultaneous femoral osteotomy and total knee arthroplasty is a technically difficult but effective treatment for patients with severe femoral deformity associated with ipsilateral osteoarthritis of the knee. We recommend that the femoral osteotomy site be secured with a plate or a locked intramedullary nail, depending on the location of the deformity and the subsequent osteotomy.

The vastus medialis muscle-splitting approach: a technique for total knee arthroplasty

Twenty-five patients who had 26 primary total knee replacements using a standard medial parapatellar arthrotomy (MPP) were prospectively compared with 14 patients who had 15 primary total knee replacements using an alternative vastus medialis muscle-splitting (VMS) arthrotomy. The randomized groups were compared with regards to daily range of motion, ability to straight-leg raise, and Knee Society scores pre-op, 1 week, and 6 weeks post-operatively. The mean day to discharge included a stay on the Physical Therapy and Rehabilitation Unit for all patients. The return of quadriceps strength, as manifested by the ability to straight-leg raise, was significantly ( P<0.05) earlier in the VMS approach (4.0 days) vs. the MPP approach (7.1 days). We could not find a difference in the Knee Society scores between the two approaches (groups). The mean day to discharge was 13.8 days in the VMS approach vs. 19.4 days in the MPP approach.