Good clinical outcomes after patellar cartilage repair with no evidence for inferior results in complex cases with the need for additional patellofemoral realignment procedures: a systematic review

Purpose Focal, patellar cartilage defects are a challenging problem as most cases have an underlying multifactorial pathogenesis. This systematic review of current literature analysed clinical results after regenerative cartilage repair of the patella with a special focus on the assessment and treatment of existing patellofemoral malalignment. Methods A systematic review was conducted to identify articles reporting clinical results after cartilage regenerative surgeries of the patella using the PubMed and Scopus database. The extracted data included patient-reported outcome measures (PROMS) and whether cartilage repair was performed alone or in combination with concomitant surgeries of underlying patellofemoral co-pathologies. In cases of isolated cartilage repair, specific exclusion criteria regarding underlying co-pathologies were screened. In cases of concomitant surgeries, the type of surgeries and their specific indications were extracted. Results A total of 35 original articles were included out of which 27 (77%) were cohort studies with level IV evidence. The most frequently used technique for cartilage restoration of the patella was autologous chondrocyte implantation (ACI). Results after isolated cartilage repair alone were reported by 15 (43%) studies. Of those studies, 9 (60%) excluded patients with underlying patellofemoral malalignment a priori and 6 (40%) did not analyse underlying co-pathologies at all. Among the studies including combined surgeries, the most frequently reported concomitant procedures were release of the lateral retinaculum, reconstruction of the medial patellofemoral ligament (MPFL), and osteotomy of the tibial tubercle. In summary, these studies showed lower preoperative PROMS but similar final PROMS in comparison with the studies reporting on isolated cartilage repair. The most frequently used PROMS were the IKDC-, Lysholm- and the Modified Cincinnati Score. Conclusion This comprehensive literature review demonstrated good clinical outcomes after patellar cartilage repair with no evidence of minor results even in complex cases with the need for additional patellofemoral realignment procedures. However, a meaningful statistical comparison between isolated patellar cartilage repair and combined co-procedures is not possible due to very heterogeneous patient cohorts and a lack of analysis of specific subgroups in recent literature. Level of evidence Level IV.

Preoperative Performance of PROMIS in Patients With Patellofemoral Malalignment and Chondral Disease

Background: Use of the Patient-Reported Outcomes Measurement Information System (PROMIS) instrument has not yet been validated in patients undergoing operative treatment for patellofemoral malalignment and chondral disease. Purpose: To evaluate the PROMIS Physical Function Computer Adaptive Testing (PF CAT) instrument in a population of patients with patellofemoral malalignment and chondral disease relative to established patient-reported outcome (PRO) instruments. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Eligible patients were prospectively enrolled at the time of indication for surgery and completed 5 PRO instruments preoperatively: 36-Item Short Form Health Survey (SF-36); Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC); Marx activity rating scale (Marx); EuroQol 5-dimension, 5-level instrument (EQ-5D-5L); and PROMIS PF CAT. Convergent and discriminant validity was assessed by measuring correlations between PROMIS PF CAT and other PRO instruments, including the Knee injury and Osteoarthritis Outcome Score (KOOS). Strength of correlation was measured by use of Spearman correlation coefficients. Results: In total, 37 patients (40 knees) were enrolled in the study. All knees underwent Fulkerson osteotomy and concomitant cartilage procedure (29 chondroplasty, 6 allograft, 5 microfracture). Mean patient age was 33.4 years, and 73% of knees were in female patients. Correlations ( r) between PROMIS PF CAT and knee PRO instruments were as follows: SF-36 PF ( r = 0.80; P < .01); KOOS Pain ( r = 0.74; P < .01); KOOS Symptoms ( r = 0.47; P < .01); KOOS Quality of Life ( r = 0.68; P < .01); KOOS Sports and Recreation ( r = 0.72; P < .01); KOOS Activities of Daily Living (ADL) ( r = 0.80; P < .01); WOMAC Function ( r = 0.80; P < .01); WOMAC Pain ( r = 0.72; P < .01); WOMAC Stiffness ( r = 0.38; P = .02); Marx ( r = 0.22; P = .31); and EQ-5D-5L ( r = 0.72; P < .01). Neither floor nor ceiling effects were observed in PROMIS PF CAT or KOOS ADL. Mean (±SD) question burden with PROMIS PF CAT was 5.6 ± 0.6 questions. Conclusion: In patients with patellofemoral malalignment and chondral disease, PROMIS PF CAT is an efficient and reliable PRO instrument to preoperatively assess patients across a spectrum of knee function without floor or ceiling effects.

Surgical treatment of symptomatic patellofemoral malalignment: Do we need an ideal patellofemoral congruency to solve the symptoms?

Background/Aim. The aim of this prospective nonrandomized study was to test functional results of different surgical strategies in the operative treatment of symptomatic patellofemoral malalignment. Our hypothesis was that immediate extensive surgery does not have serious advantage comparing to ?step by step? procedure, regarding the main symptoms and functional end result. We wanted to check whether obtaining ideal surgical patellofemoral congruency is an essential prerequisite for subsidence of the major symptoms of patellofemoral malalignment. Methods. The study included 35 patients with patellofemoral malalignment who had persistant major symptoms: patellar pain and slipping, 3 months after nonoperative treatment. Divided into three groups, they all underwent the realignment surgery, but in different extent and sequence: immediate extensive surgery, step by step surgery, and only proximal realignment. Their overall functional scores as well as major symptoms were assessed at the beginning, after the surgery, and during the 3-years follow-up period and then, compared at the end. Results. There was no significant difference in the functional results among the groups, neither at the beginning (p = 0.1318) nor at the end of the study (p = 0.3996), but the results at the beginning compared to those at the end of the study showed a statistically significant difference in all three groups (p1 = 0.005062; p2 = 0.011719; p3 = 0.000352). The same result was in regard to the major symptoms. Conclusion. The study confirmed that insisting on immediate extensive surgery in order to achieve precise and complete congruency of the patellofemoral joint, did not prove its advantage over the less invasive, individual surgical approach concerning functional scores and major symptoms.