Lateral Patellofemoral Ligament Reconstruction With a Hamstring Allograft

Background: Medial patellar instability is rare but may occur after lateral retinacular release. The lateral patellofemoral ligament is a significant stabilizer for medial and lateral patellar displacement, and soft tissue–based reconstruction may restore its stabilizing effect. Indications: Lateral patellofemoral ligament reconstruction (LPFLR) is indicated for patellar instability failing exhaustive nonoperative measures. Technique Description: Diagnostic arthroscopy for medial patellofemoral ligament (MPFL) status, patellar tracking, chondral status, and postoperative changes of lateral retinacular release is conducted. A 5-cm incision is made between the midpoint of the patella and the lateral epicondyle, or a single midline incision can be used if performing a concomitant MPFL reconstruction. Dissection is carried down to the lateral retinaculum and capsule, and two 1-cm incisions are made at the distal and proximal patella through the patellar and quadriceps tendon, respectively. The lateral epicondyle is then directly palpated, and two 1-cm incisions are made directly anterior and posterior to the epicondyle into the iliotibial band in full extension. A hamstring allograft is then shuttled in a V-shaped configuration from the quadriceps tendon through the iliotibial band and finally to the patellar tendon. Excess graft is trimmed and doubled over proximally and distally to replicate the normal (or contralateral) 0° to 15° of patellar eversion. Trial resting length and tension is set with temporary sutures through the proximal and distal doubled graft in full extension. The knee is taken through full range of motion to ensure there is no graft tightening in flexion or loosening in full extension. Eversion and patellar translation are then examined. Heavy nonabsorbable sutures are used to set length of the doubled allograft proximally and distally. Results: Case series of LPFLR have demonstrated significant improvements in patients’ pain, Lysholm score and Knee Injury and Osteoarthritis Outcome Score, and kinesiophobia with no instability events and normal range of motion at short-term follow-up. Discussion/Conclusion: Medial patellar instability can occur following lateral retinacular release and patients experiencing instability despite nonoperative treatment are likely to benefit from a soft tissue–based LPFLR. Although other nongraft-based techniques may confer similar outcomes, the authors find it more reliable to perform a lateral reconstruction as described.

Patellar retraction versus eversion on functional outcomes in total knee replacement: a randomized controlled study protocol

Background Patellar mobilization technique during total knee replacement (TKR) has been debated, with some suggesting that lateral retraction, rather than eversion, of the patella may be beneficial. This randomized controlled trial was to investigate the effects of patellar eversion on functional outcomes in TKR. Methods and analysis This single-center, prospective, randomized controlled test will be conducted in Jingjiang People's Hospital. Primary end-stage osteoarthritis patients that prepared for unilateral TKR were randomized to one of two patellar exposure techniques during the primary total knee arthroplasty: lateral retraction or eversion. The informed consent will be acquired in each patient. The primary outcome was operation time, length of hospital stay, and straight leg raising time. Second outcomes including Insall-Salvati ratio; range of motion at 1 month, 3 months, and 1 year following TKR; visual analog scale (VAS) at 1 month, 3 months; and Knee Society Score (KSS) score at 1 year following TKR. The significance level was defaulted as P < .05. Results Results will be published in relevant peer-reviewed journals. Conclusion Our study aims to systematically assess the functional outcomes of patellar eversion for TKR patients, which will provide clinical guidance for TKR patients.

Robotic-Arm Assisted Total Knee Arthroplasty Demonstrated Soft Tissue Protection

Total knee arthroplasty (TKA) typically addresses end-stage osteoarthritis. While TKA procedures have demonstrated clinical success, occasionally intraoperative complications can occur. This cadaver study examined the potential benefits of soft tissue protection in robotic-arm assisted TKA (RATKA). Six cadaver knees were prepared using RATKA by a single surgeon from a high-volume TKA joint center with no former clinical robotic experience, and compared to seven manually performed cases as a control. The presence of soft tissue disruption was assessed by having the surgeon perform visual evaluation and palpation of the medial collateral ligament (MCL), lateral collateral ligament (LCL), posterior cruciate ligament (PCL), and the patellar ligament after the procedures. The amount of tibial subluxation and patellar eversion was recorded for each case.For all RATKA cases, there was no visible evidence of disruption of any of the ligaments. All RATKA cases were successfully left with a bone island on the tibial plateau, which protected the PCL. Tibial subluxation and patellar eversion were not required for visualization. In two of the seven MTKA cases, there was slight disruption noted of the PCL, although this did not lead to any apparent change in the functional integrity of the ligament. All MTKA cases required tibial subluxation and patellar eversion to achieve optimal visualization.Aspects of soft tissue protection were noted in this cadaver study for RATKA. Standard retraction techniques during cutting are recommended. This is the first study to have soft tissue injury parameters assessed for RATKA, and may serve as a platform for future studies.

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 &gt;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.</p><p><strong>Conclusions:</strong> The different risk factors for post TKA shortening of patellar tendon include female gender and higher BMI (&gt;30 Kg/m²). However eversion of patella during TKA may not lead to an increased incidence of true patella baja.</p>

Short Term Recovery of Function following Total Knee Arthroplasty: A Randomised Study of the Medial Parapatellar and Midvastus Approaches

This pilot double blind randomised controlled study aimed to investigate whether the midvastus (MV) approach without patellar eversion in total knee arthroplasty (TKA) resulted in improved recovery of function compared to the medial parapatellar (MP) approach. Patients were randomly allocated to either the MV approach or the MP approach. Achievements of inpatient mobility milestones were recorded. Knee kinematics, muscle strength, Timed Up and Go, WOMAC, and daily step count were assessed before and up to six months after surgery. Cohen’s effect size d was calculated to inform the sample size in future trials. Twenty-eight participants (16 males, 12 females) participated. Patient mobility milestones such as straight leg raise were achieved on average 1.3 days (95% CI −3.4 to 0.7, d=0.63) earlier in the MV group. Knee extensor strength at 6 weeks after surgery was higher (95% CI −0.38 to 0.61, d=0.73) in the MV group. No trends for differences between the groups were observed in knee kinematics, TUG, WOMAC, or step count. Our results suggest a short term advantage in the first 6 weeks after surgery of the MV approach over the MP approach, but a larger study is required to confirm these findings. This trial is registered with NCT056445.