No influence of patellar fixation technique on clinical outcomes of double-bundle medial patellofemoral ligament reconstruction: a systematic review.

PURPOSE: To compare clinical outcomes of double-bundle medial patellofemoral ligament (MPFL) reconstruction with different patellar fixation techniques including Kujala score, functional failure and complications. METHODS: Pubmed, Embase, and Cochrane Library databases were searched for studies with clinical results of double-bundle MPFL reconstruction. The hamstring tendon autografts were used, and femoral fixation was performed with bone tunnel and an interference screw, and knee fixation angle was less than or equal to 45°. Patellar fixation methods were broadly categorized into 3 treatment groups: suture anchor (SA), bone tunnel (BT) and suture techniques (SU). Pooled means for Kujala score and pooled estimates for functional failure rate and complication rate were compared. RESULTS: 21 studies (23 groups) consisting of 691 knees met the inclusion criteria. 12 groups with 344 knees were in SA group, 5 groups of 161 knees were in BT group and 6 groups with 186 knees were in SU group. Statistically significant differences in Kujala score were found among three groups, 90.2 (95% CI 88.7-91.7) in SA group, 88.7 (95% CI 85.3-92.2) in BT group and 89.4 (95% CI 84.2-94.6) in SU group (all P < 0.001), but these differences were not clinically significant. No statistically significant differences were found in the positive apprehension sign rate, recurrent subluxation or dislocation rate, and major or minor complication rate among three groups. CONCLUSION: Patellar fixation with bone tunnel, suture anchor or suture techniques were all effective in the double-bundle MPFL reconstruction. The present systematic review failed to show that one technique was better than the others. More high-quality trials and randomized controlled trials are needed.

The patellar tendon wavy sign as a new secondary sign of ACL tear on MRI.

OBJECTIVE: The purpose of this study was to evaluate the diagnostic value of the patellar tendon wavy (PTW) sign for an anterior cruciate ligament (ACL) tear on MRI. METHODS: One hundred MRI scans were prospectively analyzed, with 50 patients with an ACL tear underwent an ACL reconstruction (group 1) and 50 patients with knee complaints other than ACL tear (group 2). The PTW sign was confirmed on the sagittal MRI. In addition, the patellar tendon length, tibial-femoral angle and tibial anterior translation (TAT) were compared between the groups. RESULTS: The PTW sign was present in 41/50 (82%) MRI scans in group 1 and 10/50 (20%) in group 2, with significant difference between two groups (p = 0.000). Significant differences were also found, in medial TAT (6.29 ± 3.25 mm versus 3.12 ± 2.85 mm) and in lateral TAT (7.62 ± 3.85 mm versus 1.58 ± 3.93 mm) between two groups (both p = 0.000). Comparison of MRI with and without PTW sign, ACL injury was found to be of significant difference with 41/51 (80.4%) versus 9/49 (18.4%) (p = 0.000), and both medial and lateral TAT were with significant differences, 5.39 ± 3.90 mm versus 3.99 ± 2.71 mm (p = 0.039) and 7.67 ± 3.77 mm versus 1.40 ± 3.81 mm (p = 0.000), respectively. The sensitivity and specificity of PTW sign were 82% and 80%. The positive and negative predictive value were 80.4% and 81.6%. The diagnosis accuracy was 81%. CONCLUSION: The PTW sign is a useful secondary MRI sign to establish the diagnosis of an ACL tear. It may be associated with the TAT secondary to an ACL tear. LEVEL OF EVIDENCE: Level III, diagnostic study.

Different Factors Conduct Anterior Knee Pain Following Primary Total Knee Arthroplasty: A Systematic Review and Meta-Analysis.

BACKGROUND: A systematic review and meta-analysis was performed to investigate the risks associated with anterior knee pain (AKP) following primary total knee arthroplasty (TKA). METHODS: A computerized search was performed of the following databases: MEDLINE, Embase, and Cochrane Central (published prior to July 2017). A total of 37 studies, which included 1641 cases of AKP and 168,090 TKAs, were included in the meta-analysis. RESULTS: A subgroup analysis revealed that compared with those without the following medical conditions, patients who had an infrapatellar fat pad excision and more than 12 months of follow-up (odds ratio [OR] 12.58, 95% confidence interval [CI] 3.245-48.781) were more likely to have AKP after TKA. Circumpatellar electrocautery (>12 months: OR 0.50, 95% CI 0.326-0.760; ≤12 months: OR 0.59, 95% CI 0.408-0.867) and patellar resurfacing (OR 0.25, 95% CI 0.131-0.485) may decrease the risk of AKP. Other factors, including the prosthesis bearing type (mobile bearing or fixed bearing) and the approach (midvastus compared with the medial parapatellar approach), were not significant risk factors for AKP. CONCLUSION: The use of strategies such as patellar denervation and patellar resurfacing in primary TKA is recommended because they are safe and result in good clinical outcomes in preventing AKP. Caution should be taken when using an infrapatellar fat pad excision, because there is an increased risk of AKP at long-term follow-up (>12 months). Future studies should investigate these different strategies to confirm the underlying mechanisms and help prevent the occurrence of AKP after TKA. The timing of AKP onset remains unclear and requires further research.

Lateral retinaculum plasty instead of lateral retinacular release with concomitant medial patellofemoral ligament reconstruction can achieve better results for patellar dislocation.

PURPOSE: To elucidate the outcomes of lateral retinaculum plasty versus lateral retinacular release with concomitant medial patellofemoral ligament (MPFL) reconstruction. METHODS: In a prospective study, 59 patients treated at our institution from 2012 to 2014 were included. The 59 patients were randomly divided into two groups. Group I included 27 patients who underwent lateral retinacular release and MPFL reconstruction. Group II included 32 patients who underwent lateral retinaculum plasty and MPFL reconstruction. All patients were followed up for at least 2 years and all assessments were performed both pre- and post-operation. Clinical evaluation consisted of the Kujala score, patellar medial glide test, and patellar tilt angle, patellar lateral shift, and congruence angle, measured on CT scan. RESULTS: Significant improvement was seen after surgery in both groups. The group of lateral retinaculum plasty achieved better results than the group of lateral retinacular release. No statistically significant differences were found in lateral patellar shift (ns) or congruence angle (ns) between the groups. There were significant differences in Kujala score (P < 0.05) patellar tilt angle (P < 0.05), and patellar medial glide test (P < 0.05) between the groups. CONCLUSIONS: MPFL reconstruction with lateral retinaculum plasty yielded better results than MPFL with lateral retinacular release. Postoperatively, medial and lateral function were restored, and patellar tracking was normal. Lateral retinaculum plasty is a new method that reduces the complications of lateral retinacular release for patellar dislocation. LEVEL OF EVIDENCE: II.

Medial Patellofemoral Ligament Reconstruction with Semi-Patellar Tunnel Fixation: Surgical Technique and Mid-Term Follow-Up.

BACKGROUND The present study aimed to describe a new safe and economical technique for medial patellofemoral ligament (MPFL) reconstruction with satisfactory clinical outcomes, and present the results of a four-year follow-up. MATERIAL AND METHODS Thirty-two patients with recurrent patella dislocation, who underwent MPFL reconstruction with two semi-patellar tunnels and hardware-free patellar fixation between 2011 and 2013, were included in the study. Patella stability was tested by an apprehension test preoperatively and at follow-up. Knee function was evaluated using the Kujala score, Lysholm score, and Crosby-Insall grading system. Patellar congruence angle and patellar tilt angle were measured using an axial computed tomography scan. Furthermore, objective feelings of patients and complications were recorded. RESULTS Thirty knees (30 patients) were followed for a minimum of 48 months. The apprehension test was positive in all patients preoperatively, but negative at follow-up. Kujala and Lysholm scores increased from 58.9±9.6 to 92.0±4.8 (p<0.001) and 53.3±5.6 to 91.6±3.5 (p<0.001), respectively, at the last follow-up. Seventeen patients were graded as excellent and 13 were graded as good by the Crosby-Insall grading system. The patellar congruence angle and patellar tilt angle also improved significantly. No patient experienced patellar re-dislocation, subluxation, or patella fracture. Most patients (93%) were satisfied with the surgery. CONCLUSIONS MPFL reconstruction with two semi-patellar tunnels and hardware-free patellar fixation was described and the study observations indicated it was a safe and economical surgical procedure for recurrent patella dislocation with satisfactory results. It could be an alternative surgery method for patients with patella recurrent dislocation.